Patent Publication Number: US-2021174947-A1

Title: Failed image management apparatus, operation method of failed image management apparatus, and failed image management system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. application Ser. No. 15/080,744 filed Mar. 25, 2016, which claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2015-067015, filed Mar. 27, 2015 and Japanese Patent Application No. 2015-067016, filed Mar. 27, 2015. The above applications are hereby expressly incorporated by reference, in their entirety, into the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a failed image management apparatus, an operation method of the failed image management apparatus, and a failed image management system. 
     2. Description Related to the Prior Art 
     In medical practice, medical images are captured with use of various types of imaging systems. For example, radiographic images are captured with use of a radiation imaging system, and MRI images are captured with use of a MRI (Magnetic Resonance Imaging) system. In the case of capturing such medical images, a medical staff member such as a doctor and a radiation technologist sets an imaging menu through a console of an imaging system. Imaging conditions axe preliminarily associated with the imaging menu. The imaging conditions are adjusted finely in accordance with a body type or the like of a patient by a medical staff member, and set in an imaging system. 
     When a radiographic image is captured with use of the radiation imaging system, for example, one set including a body part to be imaged such as a cephalic part and a chest part, an imaging posture such as an upright imaging posture, a supine imaging posture, and sitting imaging posture, and an imaging direction such as a front direction and a rear direction is set as an imaging menu. Additionally, a tube voltage and a tube current to be applied to a radiation source for irradiating radiation toward a patient and an irradiation time of the radiation are set as the imaging conditions. 
     In the case of capturing a medical image, imaging failure occurs due to an error in positioning a patient, body motion of a patient, an error in setting imaging conditions, or the like, in some cases. The medical image captured in such a case is hereinafter referred to as a failed image, and the failed image is useful information in considering improvement on the image capturing for a medical staff member. 
     In Japanese Patent Laid-Open Publication No. 2006-218139, a failed image management apparatus for managing failed images is proposed. According to Japanese Patent Laid-Open Publication No. 2006-218139, the failed image management apparatus stores a failed image and an imaging menu associated with each other, and delivers a failed image corresponding to a designated imaging menu, which is designated by a medical staff member on a client terminal, to the client terminal. The client terminal displays a failed image delivered from the failed image management apparatus on a display panel. Thereby, the failed image is viewed by a medical staff member. 
     The purpose for viewing a failed image and considering improvement on the image capturing for a medical staff member is to improve his/her imaging skill and decrease a frequency of imaging failure or suppress increase in the frequency of imaging failure. Therefore, the failed image to be viewed by a medical staff member need to be associated with an imaging menu in which the frequency of imaging failure or an increasing rate of the frequency of imaging failure is relatively high. To that end, it is necessary for the medical staff member to extract and designate an imaging menu in which the frequency of imaging failure or the increasing rate of the frequency of imaging failure is relatively high. 
     In order to extract and designate an imaging menu in which the frequency of imaging failure or the increasing rate of the frequency of imaging failure is relatively high, the medical staff member need to know exactly an imaging failure state of each imaging menu. However, it imposes a heavy burden on a busy medical staff member to know exactly an imaging failure state of each imaging menu and extract and designate an imaging menu in which the frequency of imaging failure or the increasing rate of the frequency of imaging failure is relatively high. 
     The frequency of imaging failure is represented by any one of the number of times of occurrence of imaging failure and the rate of the number of times of occurrence of imaging failure with respect to the total number of times of imaging (hereinafter referred to as rate of occurrence of imaging failure). However, any one of the number of times of occurrence of imaging failure and the rate of occurrence of imaging failure is insufficient to know exactly the imaging failure state because of the following reason. For example, in both of an imaging menu in which the total number of times of imaging (abbreviated as T.NUM.I in the drawings) is 100 and the number of times of occurrence of imaging failure is 20 and an imaging menu in which the total number of times of imaging is 5 and the number of times of occurrence of imaging failure is 1, the rate of occurrence of imaging failure is 20%, namely, the same. Therefore, only the rate of occurrence of imaging failure is insufficient to judge whether or not the imaging failure state is proper. Although the imaging menu in which the total number of times of imaging is 100 and the number of times of occurrence of imaging failure is 20 has a statistical reliability higher than that of the imaging menu in which the total number of times of imaging is 5 and the number of times of occurrence of imaging failure is 1, the two imaging menus are treated the same due to the same rate of occurrence of imaging failure. 
     In the case where it is impossible to know exactly the imaging failure state of each imaging menu, there is a fear that an imaging menu in which the frequency of imaging failure or the increasing rate of the frequency of imaging failure is relatively low is extracted and designated. In such a case, the possibility of decreasing the frequency of imaging failure or the possibility of suppressing the increase in the frequency of imaging failure is low even by considering improvement on the image capturing. Therefore, the consideration is all in vain and results in waste of precious time of the medical staff members. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing problems, an object of the present invention is to provide a failed image management apparatus which enables efficient consideration for improvement in image capturing, and further enables consideration for reliably decreasing frequency of imaging failure or consideration for reliably suppressing increase in the frequency of imaging failure, an operation method of the failed image management apparatus, and a failed image management system. 
     In order to achieve the above and other objects and advantages of the present invention, a failed image management apparatus of the present invention includes a first calculator and a first extractor. The first calculator calculates a first index value which quantitatively indicates an imaging failure state based on each imaging menu associated with a plurality of medical images containing failed images obtained as a result of failure in image capturing. The first calculator calculates the first index value using a first calculation formula having at least a variable based on the number of times of occurrence of imaging failure for each imaging menu and a variable based on a rate of occurrence of imaging failure for each imaging menu, or calculates the first index value using a first calculation formula having at least a variable based on an increasing rate of frequency of imaging failure for each imaging menu. The first extractor automatically extracts a target menu which is the imaging menu as a target to be subject to consideration for the purpose of preventing occurrence of imaging failure based on the first index value. 
     Preferably, the medical image is also associated with information regarding a medical staff member who performed the image capturing, and a participant as the medical staff member who attends the consideration is designated. 
     Preferably, the first calculation formula also has a variable based on the number of times of occurrence of imaging failure for each imaging menu for each participant and a variable based on the rate of occurrence of imaging failure for each imaging menu for each participant, in the case where the first index value is calculated using the first calculation formula having at least the variable based on the number of times of occurrence of imaging failure for each imaging menu and the variable based on the rate of occurrence of imaging failure for each imaging menu. 
     Preferably, the medical image is also associated with information regarding an imaging order for instructing a medical staff member to perform the image capturing. It is preferable that the first calculation formula also has a variable based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same imaging order, in the case where the first index value is calculated using the first calculation formula having at least the variable based on the number of times of occurrence of imaging failure for each imaging menu and the variable based on the rate of occurrence of imaging failure for each imaging menu. 
     Preferably, the medical image is also associated with information regarding a patient as a target for the image capturing. It is preferable that the first calculation formula also has a variable based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same patient, in the case where the first index value is calculated using the first calculation formula having at least the variable based on the number of times of occurrence of imaging failure for each imaging menu and the variable based on the rate of occurrence of imaging failure for each imaging menu. 
     It is preferable that the first calculation formula also has a variable based on the increasing rate of frequency of imaging failure of the target menu extracted at a previous consideration, in the case where the first index value is calculated using the first calculation formula having at least the variable based on the increasing rate of frequency of imaging failure for each imaging menu. 
     Preferably, the medical image is also associated with information regarding a medical staff member who performed the image capturing, and a participant as the medical staff member who attends the consideration is designated. It is preferable that the first calculation formula also has a variable based on whether or not a participant, who attended a previous consideration and was designated to attend a current consideration, failed in the image capturing corresponding the target menu extracted at the previous consideration, in the case where the first index value is calculated using the first calculation formula having at least the variable based on the increasing rate of frequency of imaging failure for each imaging menu. 
     Preferably, the medical image is also associated with information regarding date and time of the image capturing, and a calculation target period, as a period in which the medical image having the first index value to be calculated by the first extractor is captured, is designated. 
     Preferably, the failed image management apparatus further includes a second extractor for extracting a consideration image that is the failed image associated with the target menu among a plurality of the failed images. 
     Preferably, the failed image management apparatus further includes a second calculator for calculating a second index value which quantitatively indicates a degree of priority of the consideration image to be viewed. Preferably, the medical image is also associated with information regarding a medical staff member who performed the image capturing, and a participant as the medical staff member who attends the consideration is designated. The second calculator preferably calculates the second index value using a second calculation formula having at least a variable based on whether or not the failed image as the consideration image is associated with the participant. The second extractor preferably determines the failed image as the consideration image based on the second index value. 
     Preferably, the medical image is also associated with information regarding the medical staff member who performed the image capturing, and a participant as the medical staff member who attends the consideration is designated. Preferably, the second extractor replaces the target menu with another target menu and extracts the consideration image again, in the case where there is no consideration image associated with the participant among the consideration images extracted based on the target menu. Replacement of the target menus and re-extraction of the consideration images are preferably repeated until the consideration image associated with the participant is extracted. 
     It is preferable that the second extractor increases the number of failed images to be extracted as the consideration images, as the imaging failure state indicated by the first index value of the target menu with which the failed image is associated is poorer, in the case where there are a plurality of the target menus extracted by the first extractor. 
     The number of consideration images to be extracted by the second extractor is preferably designated. 
     It is preferable that the medical image is also associated with information regarding the date and time of the image capturing, and an extraction target period, as a period in which the failed image to be extracted as the consideration image by the second extractor is captured, is designated. 
     Preferably, the failed image management apparatus further includes screen output controller for controlling an output of a display screen for displaying the target menu and a second extractor for extracting a consideration image that is the failed image associated with the target menu among a plurality of the failed images, and the consideration image is also displayed on the display screen. Preferably, the failed image management apparatus further includes a second calculator for calculating a second index value which quantitatively indicates a degree of priority of the consideration image to be viewed. In the case where there are a plurality of the consideration images extracted by the second extractor, it is preferable that the consideration images arranged in accordance with the second index value are displayed on the display screen, or the consideration images each having a display size and a display position in accordance with the second index value are displayed on the display screen. 
     An operation method of a failed image management apparatus of the present invention includes a calculation step and an extraction step. The calculation step calculates an index value which quantitatively indicates an imaging failure state based on each imaging menu associated with a plurality of medical images containing failed images obtained as a result of failure in image capturing. The calculation step calculates the index value using a calculation formula having at least a variable based on the number of times of occurrence of imaging failure for each imaging menu and a variable based on a rate of occurrence of imaging failure for each imaging menu, or calculates the index value using a calculation formula having at least a variable based on an increasing rate of frequency of imaging failure for each imaging menu. The extraction step automatically extracts a target menu which is the imaging menu as a target to be subject to consideration for the purpose of preventing occurrence of imaging failure based on the index value. 
     A failed image management system including a failed image management apparatus of the present invention includes a calculator and an extractor. The calculator calculates an index value which quantitatively indicates an imaging failure state based on each imaging menu associated with a plurality of medical images containing failed images obtained as a result of failure in image capturing. The calculator calculates the index value using a calculation formula having at least a variable based on the number of times of occurrence of imaging failure for each imaging menu and a variable based on a rate of occurrence of imaging failure for each imaging menu, or calculates the index value using a calculation formula having at least a variable based on an increasing rate of frequency of imaging failure for each imaging menu. The extractor automatically extracts a target menu which is the imaging menu as a target to be subject to consideration for the purpose of preventing occurrence of imaging failure based on the index value. 
     According to the present invention, the index value is calculated using the calculation formula having at least the variable based on the number of times of occurrence of imaging failure for each imaging menu and the variable based on the rate of occurrence of imaging failure for each imaging menu. Alternatively, the index value is calculated using the calculation formula having at least the variable based on the increasing rate of frequency of imaging failure for each imaging menu. Based on the index value thus calculated, the target menu which is the imaging menu as the target to be subject to consideration for the purpose of preventing occurrence of imaging failure, is automatically extracted. Thereby, it is possible to provide the failed image management apparatus which enables efficient consideration for improvement in image capturing, and further enables consideration for reliably decreasing frequency of imaging failure or consideration for reliably suppressing increase in the frequency of imaging failure, the operation method of the failed image management apparatus, and the failed image management system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above objects and advantages of the present invention will become more apparent from the following detailed description when read in connection with the accompanying drawings, in which: 
         FIG. 1  illustrates a medical information system; 
         FIG. 2  is an explanatory view illustrating a flow of radiography from a step at which an imaging order is acquired to a step at which an imaging menu and imaging conditions are set; 
         FIG. 3  is an explanatory view illustrating a flow of radiography from a step at which a radiographic image is detected to a step at which an image file is transmitted to a PAS and a failed image management server; 
         FIG. 4  illustrates contents of the image file; 
         FIG. 5  illustrates various types of information transmitted/received between a client terminal and the failed image management server; 
         FIG. 6  is a block diagram illustrating a computer constituting the client terminal and the failed image management server; 
         FIG. 7  is a block diagram illustrating a function of a CPU of the client terminal; 
         FIG. 8  illustrates a designation screen; 
         FIG. 9  illustrates contents of designation information contained in a delivery request; 
         FIG. 10  is a block diagram illustrating a function of the CPU of the failed image management server; 
         FIG. 11  illustrates that a first calculator acquires a diagnostic image file and a failed image file; 
         FIG. 12  illustrates that the first calculator derives variables based on the number of times of occurrence of imaging failure for each imaging menu and variables based on the rate of occurrence of imaging failure for each imaging menu; 
         FIG. 13  illustrates that the first calculator derives variables based on the number of times of occurrence of imaging failure for each imaging menu for each participant and variables based on the rate of occurrence of imaging failure for each imaging menu for each participant; 
         FIG. 14  illustrates derivation results of variables based on the number of times of occurrence of imaging failure (abbreviated as NUM.I.F. In the drawings) for each imaging menu for each participant and variables based on the rate of occurrence of imaging failure (abbreviated as R.I.F. In the drawings) for each imaging menu for each participant; 
         FIG. 15  illustrates that the first calculator derives variables based on the number of times of occurrence of imaging failure for each imaging menu in image capturing corresponding to the same imaging order; 
         FIG. 16  illustrates that the first calculator derives variables based on the number of times of occurrence of imaging failure for each imaging menu in image capturing corresponding to the same patient; 
         FIG. 17  is an explanatory view illustrating a function of the first calculator for calculating a first index value; 
         FIG. 18  is an explanatory view illustrating a function of the first extractor for extracting a target menu; 
         FIG. 19  illustrates that a second extractor acquires a failed image as a consideration image; 
         FIG. 20  illustrates that a second calculator derives variables based on whether or not the failed image as the consideration image is associated with a participant and variables regarding a narrowing-down condition; 
         FIG. 21  is an explanatory view illustrating a function of the second calculator for calculating a second index value; 
         FIG. 22  is an explanatory view illustrating a function of the second extractor for extracting the failed image as the consideration image; 
         FIG. 23  illustrates that the second extractor acquires a diagnostic image as a reference image; 
         FIG. 24  is an explanatory view illustrating a screen output control function of a screen output controller; 
         FIG. 25  illustrates a conference screen in an initial display state; 
         FIG. 26  illustrates the conference screen on which a consideration image selection region is displayed; 
         FIG. 27  illustrates the conference screen on which the consideration image and the reference image are displayed; 
         FIG. 28  illustrates an accompanying information display region; 
         FIG. 29  is a flow chart illustrating a flow of processing performed by a CPU of the client terminal and a CPU of the failed image management server; 
         FIG. 30  illustrates another display example of the consideration image selection region; 
         FIG. 31  is a block diagram illustrating the function of the CPU of the failed image management server according to a second embodiment; 
         FIG. 32  illustrates contents of conference history information; 
         FIG. 33  illustrates that the first calculator acquires the failed image file; 
         FIG. 34  illustrates that the first calculator counts the number of times of occurrence of imaging failure for each imaging menu; 
         FIG. 35  illustrates that the first calculator derives variables based on an increasing rate of the number of times of occurrence of imaging failure for each imaging menu; 
         FIG. 36  illustrates that the first calculator derives variables based on whether or not a participant, who attended the previous conference and was designated to attend the current conference, failed in the imaging capturing corresponding to a target menu extracted at the previous conference; 
         FIG. 37  is an explanatory view illustrating the function of the first calculator for calculating the first index value according to the second embodiment; 
         FIG. 38  illustrates that a R/W controller updates the conference history information; 
         FIG. 39  illustrates a flow of processing performed by the second extractor according to a third embodiment; 
         FIG. 40  illustrates an allocation rate of the consideration images and the number of consideration images to be extracted for each target menu according to a forth embodiment; 
         FIG. 41  illustrates another example of the conference screen; 
         FIG. 42  illustrates an example of a display state of a target menu display region before and after selection of a check box for designating a particularly notable participant; and 
         FIG. 43  illustrates an example of a display state of the consideration image selection region before and after selection of a check box for designating a particularly notable participant. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRAL EMBODIMENT(S) OF THE PRESENT INVENTION 
     First Embodiment 
     In  FIG. 1 , a medical information system  2  includes a radiation imaging system  10 , a PACS (Picture Archiving and Communication System)  11 , a client terminal  12 , and a failed image management server  13  corresponding to a failed image management apparatus, which are connected to one another through a network  14  such as a LAN (Local Area Network) provided in a medical facility. 
     As wellknown, the radiation imaging system  10  includes a radiation source  15  for irradiating radiation such as X-rays toward a patient P as an imaging target, a radiation source controller  16  for controlling an operation of the radiation source  15  in accordance with an imaging condition, a radiographic image detector  17 , and a console  18  for controlling an operation of the radiographic image detector  17 . The imaging condition consists of a tube voltage and a tube current to be applied to the radiation source  15  and an irradiation time of the radiation. The radiographic image detector  17  receives the radiation having been irradiated from the radiation source  15  and having passed through the Patient P, and detects a radiographic image  26  (see  FIG. 3 ) corresponding to a medical image. Incidentally, although one radiation imaging system  10  is depicted in  FIG. 1 , in fact, a plurality of the radiation imaging systems  10  are provided in each of a plurality of imaging rooms. 
     Each of the PACS  11 , the client terminal  12 , and the failed image management server  13  is composed of a computer (e.g., personal computer, server computer, workstation, or the like) installed with a control program (e.g., operating system) and various types of application programs. 
     The PACS  11  includes an image database (hereinafter abbreviated as DB)  20 , in which a diagnostic image file (see  FIG. 3 ) is stored in a retrievable manner. The PACS  11  stores and manages the diagnostic image file. 
     The failed image management server  13  includes an imaging failure case example DB  21 , in which the diagnostic image file and the failed image file (see  FIG. 3 ) are stored in a retrievable manner. The failed image management server  13  stores and manages the diagnostic image file and the failed image file. 
     The diagnostic image file is an image file created based on a diagnostic image, which is usable for diagnosis, among radiographic images  26  captured by the radiation imaging system  10 . The failed image file is an image file created based on a failed image, which is unsuccessfully captured, among the radiographic images  26  captured by the radiation imaging system  10 . Note that, the cause of the failure in image capturing is an error in positioning the patient P, body motion of the patient P, an error in setting the imaging condition, or the like. 
     The client terminal  12  is operated by a medical staff member at a conference for considering improvement on the image capturing at which a plurality of medical staff members such as a radiation technologist in charge of the image capturing gather. The conference is periodically held, for example, every one month. Incidentally, although one client terminal  12  is depicted in  FIG. 1 , a plurality of the client terminals  12  may be provided for a plurality of medical staff members on one-to-one basis. 
     In  FIG. 2 , the console  18  receives an imaging order for instructing a medical staff member to perform image capturing. The imaging order is issued using an electronic medical chart by a doctor belonging to a diagnosis and treatment department such as an internal medicine department (abbreviated as “I.M. DEP.” in the drawing) and a trauma department, and transmitted to the console  18  through a RIS (Radiology Information System, not shown in the drawing). The console  18  represents the contents of an imaging menu to the medical staff member. Incidentally, instead of using the system such as the RIS, the imaging order in a printed paper version is passed from the doctor belonging to the diagnosis and treatment department to the medical staff member in some cases. In this case, the imaging order is manually inputted to the console  18  by the medical staff member. 
     The imaging order contains items such as “order ID (Identification data)”, “department as requestor”, “staff ID”, “patient ID”, and “body part to be imaged/imaging posture/imaging direction”. The order D consists of symbols and numbers, for identifying an individual imaging order, and is automatically assigned by the RIS. The name of the diagnosis and treatment department, which issued the imaging order, is inputted to the item “department as requestor”. The staff ID of the doctor as the requestor of the image capturing, who issued the imaging order, is inputted to the item “staff ID”. The patient ID of the patient P as the imaging target is inputted to the item “patient ID”. The staff ID consists of symbols and numbers, for identifying an individual medical staff member such as a doctor and a radiation technologist. The patient ID consists of symbols and numbers, for identifying an individual patient. 
     The body part to be imaged, the imaging posture, and the imaging direction, designated by the doctor who issued the imaging order, are inputted to the item “body part to be imaged/imaging posture/imaging direction”. The body part to be imaged includes cephalic part, cervical spine, chest part, abdominal part, hand, finger, elbow, and knee of a human body. The imaging posture is the posture of the patient P, such as an upright imaging posture, a supine imaging posture, and a sitting imaging posture. The imaging direction is an orientation of the patient. P toward the radiation, such as a front direction, a side direction, and a rear direction. In an example shown in  FIG. 2 , the chest part is designated as the body part to be imaged, the upright imaging posture is designated as the imaging posture, and the front direction is designated as the imaging direction. Note that, in addition to the above items, the date and time on which the PIS receives the imaging order, the purpose of the image capturing such as follow-up after surgery and response evaluation of a curative drug, a message from the doctor belonging to the diagnosis and treatment department to the radiation technologist, and the like may be added as the items. 
     In some cases, one imaging order is issued for one patient, and in other cases, a plurality of the imaging orders are issued for one patient at the same time. In the case where a plurality of the imaging orders are issued for one patient at the same time, an identification code for identifying the one patient is assigned to the order ID of each of a plurality of the imaging orders. 
     A menu/condition table  25  is stored in the console  1 . The imaging menu including the body part to be imaged, the imaging posture, and the imaging direction as one set, and the imaging condition corresponding to the imaging menu are associated with each other and registered in the menu/condition table  25 . The console  18  represents the contents of the menu/condition table  25  to the medical staff member such that the medical staff member can set the imaging menu. Incidentally, the imaging menu including the body part to be imaged and the imaging direction as one set, with the imaging posture being excluded from the imaging menu, and the imaging menu adapted to special imaging such as tomosynthesis imaging and long time-scale imaging may be provided. 
     The medical staff member confirms the contents of the imaging order using the console  18 , and selects and sets the imaging menu including the body part to be imaged, the imaging posture, and the imaging direction designated by the imaging order. Then, the medical staff member manually sets the imaging condition which is the same as the imaging condition corresponding to the set imaging menu, or the imaging condition obtained by finely adjusting the imaging condition corresponding to the set imaging menu in accordance with a body type or the like of the patient P, to the radiation source controller  16 . 
     After setting the imaging condition, the medical staff performs the positioning of each of the radiation source  15 , the radiographic image detector  17 , and the patient P to a desired position. Thereafter, the medical staff member drives the radiation source  15 , so as to irradiate radiation to the patient P. The radiation having passed through the patient P is irradiated to the radiographic image detector  17 , and thus the radiographic image detector  17  detects the radiographic image  26 . 
     In  FIG. 3 , the radiographic image detector  17  transmits the radiographic image  26  to the console  18 . The console  18  displays the radiographic image  26  to the medical staff member. The medical staff member judges whether the radiographic image  26  displayed by the console  18  is the diagnostic image or the failed image, and inputs the judgment result to the console  18 . A point of time when the medical staff member judges the radiographic image  26  as the diagnostic image corresponds to a sign of the completion of the image capturing for one imaging order. 
     The console  18  creates an image file in which the radiographic image  26  is associated with the imaging menu set at the time of capturing the radiographic image  26  and other accompanying information. As described above, there are two types of image files, namely, there are the diagnostic image file based the diagnostic image and the failed image file based the failed image. The console  18  transmits the diagnostic image f ile to the PACS  11 , and transmits the diagnostic image file and the failed image file to the failed image management server  13 . Note that, the timing of transmitting each of the image files by the console  18  may be just after each of the image files is created. As the failed image file is not necessary for diagnosis, the failed image file after being created may be stocked once and transmitted at a predetermined timing. For example, when the day&#39;s work is completed and the console  18  is shut down, the failed image files may be transmitted at a time. 
     In  FIG. 4 , the image file is in a file format compatible with DICOM (Digital Imaging and Communication in Medicine) standard, for example. The image file includes an accompanying information storage  27  in which accompanying information is stored and an image storage  28  in which the radiographic image  26  is stored. 
     In the accompanying information storage  27 , there are stored items “file I”. “date and time of imaging”, “patient ID”, “patient name”, “gender”, “date of birth”, “age”, “body height (unit: cm)”, “body weight (unit: kg)”, “inpatient/outpatient classification (abbreviated as “IP/OP CLASSIFICATION” in the drawings)”, “order ID”, “imaging menu”, “tube voltage (unit: kV)”, “tube current (unit: mA)”, “irradiation time (unit: ms)”, “staff ID”, “imaging room”, and “imaging failure flag”. 
     The file ID consists of symbols and numbers for identifying each image file, and is automatically assigned by the console  18  at the time of creating an image file. The date and time of imaging is literally the date and time when the image capturing is performed, and automatically assigned by the radiographic image detector  17  at the time of detecting the radiographic image  26 . 
     The patient ID and the like of the patient P as the imaging target are respectively inputted to the items “patient ID”, “patient name”, “gender”, “date of birth”, “age”, “body height”, “body weight”, and “inpatient/outpatient classification”. The information regarding the patient P can be obtained from HIS (Hospital Information System, not shown in the drawing), for example. Incidentally, in addition to the above items, an item “body type index” such as EMI (Body Mass Index) calculated from the body height and the body weight may be added. 
     The order ID of the imaging order of the imaging target is inputted to the item “order ID”. Until the medical staff member judges the radiographic image  26  as the diagnostic image and the sign of the completion of the image capturing is issued, the same order ID is inputted to the item “order ID”. Namely, in the case where the image capturing fails and the failed image is captured, at least one of the failed image files in each of which the same order ID is inputted and one diagnostic image file are created. The number of the failed image files in each of which the same order ID is inputted represents the number of times of occurrence of imaging failure corresponding to the order ID. 
     The imaging menu set by the medical staff ember is set to the item “imaging menu”. The tube voltage, tube current, and irradiation time set to the radiation source controller  16  by the medical staff member are respectively inputted to the items “tube voltage”, “tube current”, and “irradiation time”. The staff ID of the medical staff member who performed the image capturing (radiographer) is inputted to the item “staff ID”. The imaging room in which the image capturing was performed is inputted to the item “imaging room”. 
     An imaging failure flag is used to distinguish the image file between the diagnostic image file and the failed image file. In the case of the diagnostic image file, “0” is inputted to the item “imaging failure flag”, and in the case of the failed image file, “1” is inputted to the item “imaging failure flag”. 
     Since “1” is inputted to the item “imaging failure flag” in  FIG. 4 , the image file shown in  FIG. 4  is the failed image file. The radiographic image  26  stored in the image storage  28  is the failed image. As shown by the botted lines, positional displacement due to a positioning error of the patient P, image blur due to body motion of the patient P, excessive concentration or insufficient concentration due to the setting error in the imaging condition, and the like appear. 
     In  FIG. 5 , the client terminal  12  outputs the delivery request to the failed image management server  13 . The failed image management server  13  receives the delivery request from the client terminal  12 . The failed image management server  13  automatically extracts a target menu as the imaging menu to be considered at the conference, and a consideration image  26 C (see  FIG. 27 ) to be viewed by the medical staff members at the conference, in response to the delivery request. The failed image management server  13  generates a conference screen  30  (corresponding to display screen, also see  FIG. 25  to  FIG. 27 ) for displaying the target menu and the consideration image  26 C, and outputs the conference screen  30  to the client terminal  12  as a requestor of the delivery request. 
     The failed image management server  13  outputs the conference screen  30  in the XML data format for web delivery, which is described by a markup language such as XML (Extensible Markup Language), for example. The client terminal.  12  reproduces and displays the conference screen  30  on the web browser based on the XML data. Incidentally, instead of the XML, a data description language such as JSON (JavaScript (registered trademark) Object Notation) may be used. 
     In  FIG. 6 , the computer constituting the client terminal  12  and the computer constituting the failed image management server  13  have the same basic structure. Each of the computers includes a storage device  35 , a memory  36 , a CPU (Central Processing Unit)  37 , a communication section  38 , a display panel  39 , and an input device  40 , which are connected to one another through a data bus  41 . 
     The storage device  35  is incorporated in the computer constituting the client terminal  12  or the like. Alternatively, the storage device  35  is a hard disk drive connected through a cable or a network, or a disk array composed of two or more connected hard disk drives. The storage device  35  stores a control program such as an operating system, various types of application programs, and display data of various types of operation screens associated with the programs. 
     The memory  36  is a working memory, which is used by the CPU  37  to execute processing. The CPU  37  loads the programs, which are stored in the storage device  35 , into the memory  36 , and executes the processing in accordance with the programs. Thereby, the CPU  37  centrally controls each section of the computer. 
     The communication section  38  is a network interface that controls transmissions of various types of information through the network  14 . The display panel  39  displays various types of operation screens in accordance with the operation of the input device  40  such as a mouse and a keyboard. The operation screen is provided with an operation function using a GUI (Graphical User Interface). A computer, which constitutes the client terminal  12  or the like, receives the input of an operation command from the input device  40  through the operation screen. 
     Incidentally, in the descriptions below, a suffix “A” is attached to a numeral that denotes each component of the computer that constitutes the client terminal  12 , and a suffix “B” is attached to a numeral that denotes each component of the computer that constitutes the failed image management server  13 , for distinction. 
     In  FIG. 7 , upon the startup of the web browser, a CPU  37 A of the client terminal  12  works together with the memory  36 , and thereby functions as a GUI controller  45  and a browser controller  46 . 
     The GUI controller  45  displays various types of operation screens on the display panel  39 A, and receives an operation command inputted using the input device  40 A through various types of operation screens. The operation command is a command for delivering the conference screen  30  or the like. The GUI controller  45  outputs the received operation command to the browser controller  46 . 
     The browser controller  46  controls the operation of the web browser. The browser controller  46  issues the delivery request to the failed image management server  13 . Further, the browser controller  46  receives the XML data of the conference screen  30  from the failed image management server  13 . The browser controller  46  reproduces the conference screen  30  to be displayed on the web browser based on the XML data, and outputs the conference screen  30  to the GUI controller  45 . The GUI controller  45  displays the conference screen  30  on the display pane  39 A. 
     At the conference, the medical staff member accesses a site established by the failed image management server  13  on the web browser. Upon completion of the access to the site, a designation screen  50  as shown in FIG. R is displayed on the display panel  39 A. The designation screen  50  is a screen for inputting a command for delivering the conference screen  30 . 
     In  FIG. 8 , a designation screen  50  includes a participant selection region  51 , an input region  52  for inputting the number of target menus, the number of consideration images, and a target period (hereinafter simply referred to as input region  52 ), and a narrowing-down condition selection region  53 . The participant selection region  51  is a region for selecting medical staff members (participants) who attend the conference. The full name of each medical staff member is displayed in a participant selection region  51 . Check boxes  54  for selecting the medical staff members as the participants, and a scroll bar  55  for displaying hidden full names of medical staff members and hidden check boxes are provided in the participant selection region  51 . The check box  54  is selectable using a cursor  56 , and a check mark is displayed in the check box  54  selected using the cursor  56 . 
     The participants are displayed in the participant selection region  51  by acquiring the information regarding the staff ID from the item “staff ID” in each of the diagnostic image file and the failed image file stored in the imaging failure case example DB  21  and converting the acquired staff ID to the full name. Incidentally, a function for selecting all the medical staff members as the participants collectively and a function for selecting the participants for each group containing some of the medical staff members may be provided to the participant selection region  51 . 
     The input region  52  is a region for inputting the number of target menus (abbreviated as NUM.T.M. in the drawings), the number of consideration images  26 C, and the period. The period includes a calculation target period and an extraction target period. The calculation target period is a period in which the radiographic image  26  having the first index value to be calculated by a first calculator  72  (see  FIG. 10 ) was captured. The extraction target period is a period in which the failed image to be extracted as the consideration image  26 C by a second extractor  74  (see  FIG. 10 ) was captured. 
     The item input region  52  is provided with an input box  57  for inputting the number of target menus, an input box  58  for inputting the number of consideration images  26 , and input boxes  59  and  60  for inputting the period. The numerical value indicating the number of target menus is inputted to the input box  57 . The numerical value indicating the number of consideration images  26   r  is inputted to the input box  58 . The starting date of the period is inputted to the input box  59 , and the ending date of the period is inputted to the input box  60 . Here, the calculation target period and the extraction target period are designated together using the input boxes  59  and  60 . However, the calculation target period and the extraction target period may be designated separately by providing an input box dedicated for the calculation target period and an input box dedicated for the extraction target period. 
     The narrowing-down condition selection region  53  is a region for selecting the narrowing-down condition. The narrowing-down condition includes the age and gender of the patient, inpatient/outpatient classification, a period of time of the image capturing, a day of week of the image capturing, and the imaging room. The narrowing-down condition selection region  53  is provided with pull-down menus  61 ,  62 ,  63 ,  64 ,  65 , and  66  each for selecting the narrowing-down condition. Incidentally, the narrowing-down condition may include the ranges of body height and body weight of the patient, and the range of the imaging condition such as the tube voltage. 
     At least one of the check boxes  54  in the participant selection region  51  is required to be selected. In contrast, the input of the number of target menus to the input box  57 , the input of the number of consideration images  26 C to the input box  58 , and the input of the period to the input boxes  59  and  60  in the item input region  52  may be arbitrarily performed. As well, the selection of the pull-down menus  61  to  66  each for selecting the narrowing-down condition in the narrowing-down condition selection region  53  may be arbitrarily performed. 
     A start button  67  is disposed under the narrowing-down condition selection region  53 . In response to selection of the start button  67  after the selection of at least one of the check boxes  54 , the command for delivering the conference screen  30  is received by the GUI controller  45 , and outputted to the browser controller  46 . 
     In  FIG. 8 , as the participants, four participants, “Tadashi YAMADA”, “Ichiro KAWAMURA”, “Misaki OIWA”, “Ayaka HYAFUYASU” are selected. (Each person&#39;s name is abbreviated as an initial in terms of space in the drawings but it is fully displayed without abbreviations in practice.) “1” is inputted to the input box  57 , “50” is inputted to the input box  58 , “2015.01.05” is inputted to the input box  59 , and “2015.03.13” is inputted to the input box  60 , respectively. Further, in  FIG. 8 , as the narrowing-down condition, gender “male” (abbreviated “M” in the drawings), inpatient/outpatient classification “outpatient” are respectively selected, by way of example. 
     The browser controller  46  generates designation information shown in  FIG. 9  in response to the command for delivering the conference screen  30  from the GUI controller  45 . The designation information includes items of the staff ID of the participant, the number of target menus, the number of consideration images, the period, and the narrowing-down condition. The information corresponding to the selected state and the inputted state in each of the regions  51  to  53  in the designation screen  50  is inputted to the items. The browser controller  46  issues the request for delivering the conference screen  30  containing the designation information. 
       FIG. 9  illustrates the designation information in which information corresponding to the selected state and the inputted state in the designation screen  50  shown in  FIG. 8  is contained. Incidentally, the staff ID “R0001” inputted to the item of the staff ID corresponds to “Tadashi YAMADA”, the staff ID “R0002” inputted to the item of the staff ID corresponds to “Ichiro KAWAMURA”, the staff ID “R0005” inputted to the item of the staff ID corresponds to “Misaki OIWA”, and the staff ID “R0008” inputted to the item of the staff ID corresponds to “Ayaka HYAKUYASU” as the participants. 
     As shown in  FIG. 10 , a failed image management program  70  is stored in a storage device  35 B of the failed image management server  13 . The failed image management program  70  is an application program for making the computer constituting the failed image management server  13  function as the failed image management apparatus. The failed image management program  70  corresponds to an operation program. 
     Upon the startup of the ailed image management program  70 , the CPU  37 B of the failed image management server  13  works together with the memory  36 , such that the CPU  37 B and the memory  36  function as a receiving unit  71 , the first calculator  72 , a first extractor  73 , the second extractor  74 , a second calculator  75 , and a screen output controller  76 . 
     The receiving unit  71  receives the delivery request from the client terminal  12 . The receiving unit  71  outputs the information regarding the staff ID of the participant and the information regarding the period as the designation information contained in the delivery request to the first calculator  72 , and outputs the information regarding the period as the designation information contained in the delivery request to the first extractor  73 . Further, the receiving unit  71  outputs the information regarding the number of consideration images and the information regarding the extraction target period to the second extractor  74 , and outputs the information regarding the staff ID of the participant and the information regarding the narrowing-down condition to the second calculator  75 . Furthermore, the receiving unit  71  outputs the information regarding the staff ID of the participant to the screen output controller  76 . 
     The first calculator  72  calculates the first index value quantitatively indicating the imaging failure state for each of the imaging menus based on the imaging menus inputted in the diagnostic image file and the failed image file stored in the imaging failure case example DB  21 . The first extractor  73  automatically extracts the target menu based on the first index value. 
     The second extractor  74  extracts the failed image file, in which the target menu extracted by the first extractor  73  is inputted, from a plurality of the failed image files stored in the imaging failure case example DB  21 . The second calculator  75  calculates a second index value quantitatively indicating a degree of priority of the consideration image  26 C in the case where the consideration image  26 C is viewed by the participants. 
     The screen output controller  76  generates the conference screen  30  based on the target menu extracted by the first extractor  73 , the failed image file extracted by the second extractor  74 , and the like. The screen output controller  76  outputs the XML data of the generated conference screen  30  to the client terminal  12  as the requestor of the delivery request. 
     In  FIG. 1 , the first calculator  72  receives the information regarding the period from the receiving unit  71 . The first calculator  72  outputs a search command designating the same period as the received period to the imaging failure case example DE  21 . In response to the search command from the first calculator  72 , the imaging failure case example DB  21  searches the diagnostic image file and the failed image file in each of which the date and time of imaging corresponding to the designated period is inputted, and outputs a search result  80  to the first calculator  72 . 
     Note that, in the case where the period is not inputted in the designation screen  50  and there is no information regarding the period in the designation information, all the diagnostic image files and the failed image files in the imaging failure case example DB  21  are outputted as the search result  80  from the imaging failure case example DB  21  to the first calculator  72 . 
     In  FIG. 11 , as the period, “from 2015.01.05 to 2015.03.13” is illustrated by way of example in the similar manner as  FIGS. 8 and 9 . Therefore, the search result  80  consists of the diagnostic image files and the failed image files in each of which the date and time of imaging corresponding to the period “from 2015.01.05 to 2015.03.13” is inputted. 
     In  FIG. 12 , the first calculator  72  generates intermediate process data  81  based on the search result  80 . Specifically, at first, the first calculator  72  focuses attention on the imaging menus of the diagnostic image file and the failed image file in the search result  80 , and counts the total number of times of imaging by summing up the number of diagnostic image files and the number of failed image files for each imaging menu. 
     Next, based on the number of failed image files in the search result  80 , the number of times of occurrence of imaging failure is counted for each imaging menu, and further the number of times of occurrence of imaging failure is divided by the total number of times of imaging, so as to calculate the rate of occurrence of imaging failure that is the rate of the number of times of occurrence of imaging failure relative to the total number of times of imaging for each imaging menu. For example, in the case of the imaging menu “chest part/upright imaging posture/front” (abbreviated as “C.P./U.I.P./F” in the drawings), the total number of times of imaging is 200, the number of times of occurrence of imaging failure is 30, and thus the rate of occurrence of imaging failure expressed by (30/200)×100 equals to 15%. 
     After the counting of the number of times of occurrence of imaging failure and the calculation of the rate of occurrence of imaging failure, the first calculator  72  ranks each imaging menu according to the number of times of occurrence of imaging failure in descending order and the rate of occurrence of imaging failure in descending order. Then, by referring to a table  85  according to rank and variable, a variable X1 based on the number of times of occurrence of imaging failure in accordance with the rank thereof, and a variable X2 based on the rate of occurrence of imaging failure in accordance with the rank thereof are derived for each imaging menu. The variable X1 is a variable based on the number of times of occurrence of imaging failure for each imaging menu, and the variable X2 is a variable based on the rate of occurrence of imaging failure for each imaging menu. 
     The table  85  according to rank and variable is a data table in which variables corresponding to the rank are registered, and stored in the storage device  35 B, for example. Here, a variable “10” Is registered for the first rank, a variable “9” is registered for the second rank, . . . , a variable “2” is registered for the ninth rank, and a variable “I” is registered for the tenth rank. Namely, the variable is decreased by 1 from “10” registered for the first rank. A variable “0” is registered for the 11th or lower rank. 
     In the case of the imaging menu “chest part/upright imaging posture/front”, for example, the number of times of occurrence of imaging failure is ranked at third place, and therefore “8” is derived as the variable X1, and the rate of occurrence of imaging failure is ranked at sixth place, and therefore “S” is derived as the variable X2. The variables X1 and X2 are registered in the intermediate process data  81 . In the case of the imaging menu “abdominal part/upright imaging posture/front” (abbreviated as “A.P./U.I.P./F” in the drawings), the number of times of occurrence of imaging failure is ranked at 12th place and the rate of occurrence of imaging failure is ranked at 16th place, namely, both of them are ranked at lower than 11th place. Therefore, “0” is derived as each of the variables X1 and X2, and registered in the intermediate process data  81 . 
     In  FIG. 13 , the first calculator  72  receives the information regarding the staff IDs of the participants from the receiving unit  71 . The first calculator  72  generates intermediate process data  82  based on the information regarding the staff IDs and the search result  80 . The first calculator  72  focuses attention on the imaging menus and the staff IDs in the diagnostic image file and the failed image file in the search result  80 , and subjects the diagnostic image file and the failed image file, in which the staff IDs of the participants are inputted, to the same process as in the case of the intermediate process data  81 , so as to generate the intermediate process data  82 . 
     As shown in  FIG. 14 , the intermediate process data  82  is obtained by gathering the intermediate process data  81  of each of the participants. Here, as the staff IDs of the participants, “R0001”, “R0002”, “R0005”, and “R0008” are illustrated by way of example in the similar manner as  FIGS. 8 and 9 , and variables X3, X5, X7, and X9 based on the number of times of occurrence of imaging failure and variables X4, X6, X8, and X10 based on the rate of occurrence of imaging failure are derived for the respective staff IDs. The variables X3, X5, X7, and X9 are variables based on the number of times of occurrence of imaging failure for each imaging menu for each participant, and the variables X4, X6, X8, and X10 are variables based on the rate of occurrence of imaging failure for each imaging menu for each participant. Note that, regarding the staff ID “R0005” and “R0008”, due to the limitation of drawing space, the number of times of occurrence of imaging failure, the rate of occurrence of imaging failure, and the like are not shown in the drawing. 
     Further, as shown in  FIG. 15 , the first calculator  72  focuses attention on the imaging menu and the order ID in the failed image file in the search result  80 , and generates intermediate process data  83 . Specifically, the first calculator  72  extracts the order ID and the imaging menu of two or more failed image files in each which the same order ID is inputted among the failed image files in the search result  80 . Then, the first calculator  72  registers the number of failed image files as the number of times of occurrence of imaging failure. The first calculator  72  derives a variable X11 based on the number of times of occurrence of imaging failure. Here, the fir st calculator  72  derives a numerical value, which is equal to the number of times of occurrence of imaging failure, as the variable X11. The variable X11 is a variable based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same imaging order. 
     In  FIG. 15 , there are two failed image files in each of which the order ID “OD0001” and the imaging menu “chest part/upright imaging posture/front” are inputted in the search result  60 , and therefore the order ID “OD0001”, the imaging menu “chest part/upright imaging posture/front”, the number of times of occurrence of imaging failure “2”, and the variable X11 “2” are registered in the intermediate process data  83 . 
     Further, as shown in  FIG. 16 , the first calculator  72  focuses attention on the imaging menu and the patient ID in the failed image file in the search result  80 , and generates intermediate process data  84 . Specifically, the first calculator  72  extracts the patient ID and the imaging menu in two or more failed image files in each of which the same patient ID is inputted among the failed image files in the search result  80 . Then, the first calculator  72  registers the number of failed image files as the number of time of occurrence of imaging failure. The first calculator  72  derives a variable X12 based on the number of times of occurrence of imaging failure. Here, as the variable X12, as in the case of the variable X11, a numerical value which is the same as the number of times of occurrence of imaging failure is derived. The variable X12 is a variable based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same patient. 
     In  FIG. 16 , there are two failed image files in each of which the patient ID “P0001” and the imaging menu “chest part/upright imaging posture/front” are inputted in the search result  80 , and therefore the patient ID “P0001”, the imaging menu “chest part/upright imaging posture/front”, the number of times of occurrence of imaging failure “2”, and the variable X12 “2” are registered in the intermediate process data  84 . Incidentally, in the case where there are two or more failed image files, in each of which the same patient ID is inputted, for a plurality of the imaging menus in the search result  80 , the number of times of occurrence of imaging failure and the variable X12 for each imaging menu are registered, as shown in the item of patient ID “P0010” in the intermediate process data  84 . 
     In  FIG. 17 , the first calculator  72  reads out each variable Xi (i=1 to 12) from each of the intermediate process data  81  to  84 . The first calculator  72  calculates the first index value for each imaging menu using a first calculation formula ΣXi for obtaining summation of the variables Xi. The first calculator  72  outputs a calculation result  86  of the first index value to the first extractor  73  and the screen output controller  76 . 
     The first index value may be calculated by adding or multiplying an adequate weighting coefficient to each variable Xi. For example, 10 is added to each of the variable X1 based on the number of times of occurrence of imaging failure for each imaging menu and the variable X2 based on the rate of occurrence of imaging failure for each imaging menu. Alternatively, each of the variable X11 based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same imaging order and the variable X12 based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same patient is multiplied by 2. In this case, the weighting coefficient may be configured to be settable on the client terminal  12 . 
     Note that, since there are four patients here, there are four variables X3, X5, X7, and X9 based on the number of times of occurrence of imaging failure for each imaging menu for each participant, and there are four variables X4, X6, X8, and X10 based on the rate of occurrence of imaging failure for each imaging menu for each participant. However, the change in the number of participants varies the number of the variables. Therefore, the suffix “i” is not limited to 1 to 12 described above. Further, although the suffix “i” of the variable based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same imaging order is set to 11, and the suffix “i” of the variable based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same patient is set to 12, for the convenience of explanation, the suffix “i” varies depending on the number of the participants. 
     In  FIG. 18 , the first extractor  73  receives the information regarding the number of target menus from the receiving unit  71  and the calculation result  86  of the first index value from the first calculator  72 . The first extractor  73  extracts the designated number of target menus based on the calculation result  86 . 
     More specifically, the first extractor  73  generates intermediate process data  90  in which the imaging menus are sorted in descending order of the first index value of the calculation result  86 . Then, the first extractor  73  extracts the imaging menu as the target menu in order of rank of the first index value from first place in the intermediate process data  90 , and stops the extraction at the point of time when the number of extracted target menus reaches the designated number. The first extractor  73  outputs the target menus extracted as described above as an extraction result  91  to the second extractor  74  and the screen output controller  76 . 
     Note that, in the case where the number of the target menus is not inputted in the designation screen  50  and there is no information regarding the number of target menus in the designation information, three imaging menus ranked at first to third places in the intermediate process data  90  are extracted as the target menus, for example. 
     In  FIG. 18 , the number of the target menus is set to “1” and the imaging menu ranked at first place in the intermediate process data  90  is “chest part/upright imaging posture/front”, and therefore the imaging menu “chest part/upright imaging posture/front” ranked at first place is extracted as the target menu. 
     In  FIG. 19 , the second extractor  74  receives the information regarding the period from the receiving unit  71  and an extraction result  91  of the target menu from the first extractor  73 . The second extractor  74  outputs the period which is the same as the received period, the imaging menu which is the same as the received target menu, and the search command which designates an imaging failure flag “1” (failed image file) to the imaging failure case example DB  21 . The imaging failure case example DB  21  searches the failed image file, in which the date and time of imaging corresponding to the period and the imaging menu that is the same as the target menu are inputted, in response to the search command from the second extractor  74 , and outputs a search result  95  to the second extractor  74 . The second extractor  74  outputs the search result  95  to the second calculator  75 . 
     Note that, in the case where the period is not inputted in the designation screen  50  and there is no information regarding the period in the designation information, all the failed image files, in each of which the imaging menu that is the same as the target menu in the imaging failure case example DB  21  is inputted, are outputted as the search result  95  from the imaging failure case example DB  21  to the second extractor  74 . 
     In  FIG. 19 , as the period, “from 2015.01.05 to 2015.03.13” is illustrated by way of example in the similar manner as  FIG. 9  and the like. Further, as the target menu, “chest part/upright imaging posture/front” is illustrated by way of example in the similar manner as  FIG. 18 . Therefore, the search result  95  consists of the failed image files, in each of which the date and time of imaging corresponding to the period “from 2015.01.05 to 2015.03.13” and the imaging menu “chest part/upright imaging posture/front.” are inputted. 
     In  FIG. 20 , the second calculator  75  receives the information regarding the staff Ds of the participants and the information regarding the narrowing-down condition from the receiving unit  71 . Further, the second calculator  75  receives the search result  95  from the second extractor  74 . 
     The second calculator  75  generates intermediate process data  98  based on the search result  95 . Specifically, at first, the second calculator  75  focuses attention on the staff ID in the failed image file of the search result  95 , and derives a variable Y1 regarding the participant, and registers the variable Y1 for each file ID in the failed image file of the search result  95 . The variable Y1 is a variable based on whether or not the failed image as the consideration image  26 C is associated with the participant. 
     Regarding the failed image file in which a staff D that is the same as the staff ID of the participant is inputted, namely, the failed image file based on the failed image captured by the participant, “1” is derived aa the variable Y1. In contrast, regarding the failed image file in which a staff ID that is different from the staff ID of the participant is inputted, namely, the failed image file based on the failed image captured by a person other than the participant, “0” is derived as the variable Y1. 
     In  FIG. 20 , as the staff IDs of the participants, the staff IDs “R0001”, “R0002”, “R0005”, and “R0008” are illustrated by way of example in the similar manner as  FIG. 9  and the like. Further, since the staff IDs of the participants “R0001” and “R0002” are inputted in the failed image files having the file IDs “F0110” and “F0115”, respectively, the variable Y1 “1” is registered in the item of the file ID of each of the failed image files of the intermediate process data  98 . 
     In contrast, in the failed image file having the file ID “F0250”, a staff ID “R0010” that is different from the staff ID of the participant is inputted, and therefore a variable Y1 “0” is registered in the item of the file ID “F0250” of the intermediate process data  98 . 
     Next, the second calculator  75  focuses attention on the item designated by the narrowing-down condition in the accompanying information of the failed image file of the search result  95 , and derives variables Y2 to Y7 regarding the narrowing-down condition and registers the variables Y2 to Y7 for each file ID. The variable Y2 corresponds to the age, the variable Y3 corresponds to the gender, the variable Y4 corresponds to the inpatient/outpatient classification, the variable Y5 corresponds to the period of time, the variable Y6 corresponds to the day of week, and the variable Y7 corresponds to the imaging room, as the narrowing-down condition. 
     Regarding the failed image file in which the accompanying information corresponding to the narrowing-down condition is inputted, “1” is derived as the variables Y2 to Y7. In contrast, regarding the failed image file in which the accompanying information that does not correspond to the narrowing-down condition is inputted, “0” is derived as the variables Y2 to Y7. 
     Note that, the second calculator  75  derives only the variable corresponding to the narrowing-down condition from the receiving unit  71  among the variables Y2 to Y7. Other variables are not derived as shown by diagonal lines in the drawing. Further, in the case where the narrowing-down condition is not selected in the designation screen  50  and there is no information regarding the narrowing-down condition in the designation information, the second calculator  75  does not derive the variables Y2 to Y7, and derives only the variable Y1. 
     In  FIG. 20 , as the narrowing-down condition, the gender “male” and the inpatient/outpatient classification “outpatient” are illustrated by way of example in the similar manner as  FIG. 9 . Since the gender “male” and the inpatient/outpatient classification “outpatient”, which correspond to the narrowing-down condition from the receiving unit  71 , are inputted in the failed image file having the file ID “F0110”, the variable Y3 “1” and the variable Y4 “.” are registered in the item of the file ID “F0110” of the intermediate process data  98 . 
     In contrast, since the gender “female” (abbreviated “F” in the drawings) and the inpatient/outpatient classification “inpatient”, which do not correspond to the narrowing-down condition from the receiving unit  71 , are inputted in the failed image file having the file ID “F0250”, “0” is registered as the 1$ variables Y3 and Y4 in the item of file ID “F0250” of the intermediate process data  98 . 
     In  FIG. 21 , the second calculator  75  reads out each variable Yj (j=1 to 7) from the intermediate process data  98 . The second calculator  75  calculates a second index value for each failed image file using a second calculation formula ΣYj for obtaining summation of the variables Yj. The second calculator  75  outputs a calculation result  99  of the second index value to the second extractor  74  and the screen output controller  76 . Incidentally, as in the case of the first index value, the second index value may be calculated by adding or multiplying an adequate weighting coefficient to each variable Yj. Further, the weighting coefficient may be configured to be settable on the client terminal  12 . 
     In  FIG. 22 , the second extractor  74  receives the information regarding the number of the consideration images from the receiving unit  71  and a calculation result  99  of the second index value from the second calculator  75 . The second extractor  74  extracts the designated number of failed image files (failed images as the consideration images  26 C) based on the calculation result  99 . 
     More specifically, the second extractor  74  generates intermediate process data  103  in which the file IDs of the failed image files of the search result  95  are sorted in descending order of the second index value of the calculation result  99 . The second extractor  74  registers the file IDs of the failed image files each having the same second index value in the same rank, and assigns a serial number to each of the file IDs in ascending order of the number of the file ID. Then, the second extractor  74  extracts the failed image file in ascending order of the serial number from the failed image file having the file ID assigned with the serial number “1” in the intermediate process data  103 , and stops the extraction at the point of time when the number of extracted failed image files reaches the designated number. The second extractor  74  outputs the failed image files extracted as described above as an extraction result  104  to the screen output controller  76 . 
     Note that, in the case where the number of consideration images is not inputted in the designation screen  50  and there is no information regarding the number of the consideration images in the designation information, ten failed image files having the file IDs assigned with the serial numbers “1” to “10” are extracted. Further, in the case where the number of failed image files of the search result  95  does not reach the designated number, all the failed image files of the search result  95  are extracted regardless of the second index value. 
     In  FIG. 22 , the number of consideration images is set to “50”, the file ID “F0110” is registered with the serial number “1”, the file ID “F0113” is registered with the serial number “2”, . . . , the file ID “F0195” is registered with the serial number “49”, and the file ID “F0200” is registered with the serial number “50” in the intermediate process data  103 , and therefore the failed image files having the file IDs “F0110”, “F0113”, . . . , “F0195”, and “F0200” are extracted. 
     In  FIG. 23 , after the extraction of the failed image files, the second extractor  74  searches the diagnostic images as reference images  26 R (see  FIG. 27 ). Specifically, the second extractor  74  outputs a search command designating an imaging menu which is the same as the target menu, a patient ID which is the same as that of the failed image file of the extraction result  104 , and an imaging failure flag “0” (diagnostic image file) to the imaging failure case example DB  21 . In response to the search command from the second extractor  74 , the imaging failure case example DB  21  searches a diagnostic image file, in which an imaging menu that is the same as the target menu containing the diagnostic image file having the same patient ID as that of the failed image file of the extraction result  104  is inputted, and outputs the search result  105  to the second extractor  74 . The second extractor  74  outputs the search result  105  to the screen output controller  76 . Instead of the patient ID, the order ID may be designated by the search command. 
     In  FIG. 23 , as the target menu, the target menu “chest part/upright imaging posture/front” is illustrated byway of example in the similar manner as  FIG. 18  and the like. Therefore, the search result  105  consists of the diagnostic image files in each of which the imaging menu “chest part/upright imaging posture/front” is inputted. Further, as the patient ID of the failed image file of the extraction result  104 , “P0050” and “P0070” are illustrated by way of example. Therefore, the diagnostic image files having the patient IDs “P0050” and “P0070”, and the diagnostic image file having another patient ID such as “P0060” and “P0150” are mixed in the search result  105 . 
     In  FIG. 24 , the screen output controller  76  receives the information regarding the staff IDs of the participants f rom the receiving unit  71 , the calculation result  86  of the first index value from the first calculator  72 , and the extraction result  91  of the target menu from the first extractor  73 . Further, the screen output controller  76  receives the calculation result  99  of the second index value from the second calculator  75 , the extraction result  104  of the failed image file and the search result  105  of the diagnostic image file from the second extractor  74 . The screen output controller  76  generates the conference screen  30  based on the information regarding the staff IDs of the participants, the calculation results  86  and  99 , the extraction results  91  and  104 , and the search result  105 . 
     More specifically, the screen output controller  76  displays the information regarding the participants based on the information regarding the staff IDs of the participants on the conference screen  30 . Further, the screen output controller  76  displays the target menu based on the extraction result  91  on the conference screen  30 . 
     Further, the screen output controller  76  displays the consideration image  26 C based on the extraction result  104  and the reference image  26 R based on the search result  105  on the conference screen  30 . The consideration image  26 C is the radiographic image  26  (failed image) stored in the image storage  26  of the failed image file of the extraction result  104 . The reference image  26 R is the radiographic image  26  (diagnostic image) stored in the image storage  28  of the diagnostic image file of the search result  105 . 
     In the case where there are a plurality of the target menus extracted by the first extractor  73 , the screen output controller  76  displays the target menus arranged in accordance with the first index values of the calculation result  86  on the conference screen  30 . Further, in the case where there are a plurality of the failed image files extracted by the second extractor  74 , namely, in the case where there are a plurality of the consideration images  26 C, the screen output controller  76  displays the consideration images  26 C arranged in accordance with the second index values of the calculation result  99  on the conference screen  30 . 
     In  FIG. 25  illustrating the conference screen  30  in an initial display state, the conference screen  30  includes a target menu display region  110 , a participant display region  111 , a consideration image display region  112 , a reference image display region  113 , and a reference image candidate display region  114 . 
     The display state of the target menu display region  110  is in accordance with the information regarding the staff D of the participants, the calculation result  86  of the first index value, and the extraction result  91  of the target menu. The target menu display region  110  consists of a display field  110 A for icons  115  representing individual participants and a display field  110 B for the target menus. The icon  115  in the display field  110 A represents that there is the consideration image  26 C captured by the participant represented by the icon  115  among the consideration images  26 C extracted in accordance with the target menu in the display field  110 B. 
     The target menus are arranged from the top in descending order of the first index value in the display field  110 B. Expand buttons  116  are provided next to the target menus on one-to-one basis. 
     The display state of the participant display region  111  is in accordance with the information regarding the staff IDs of the participants. The icons  115  and the full names of the participants are displayed in the participant display region  111 . The icons  115  displayed in the participant display region  111  are the same as those displayed in the display field  110 A of the target menu display region  110 . The icons  115  are different from one another in the color and the pattern as shown by the hatching so as to distinguish the individual participants. 
     In  FIG. 25 , three target menus “chest part/upright imaging posture/front”, “chest part/upright imaging posture/rear” (abbreviated as “C.P./U.I.P./R” in the drawings), and “abdominal part/upright imaging posture/front” are displayed in the display field  110 B, by way of example. In this case, the target menu “chest part/upright imaging posture/front” displayed at the top in the display order has the largest first index value among the three target menus. The target menu “abdominal part/upright imaging posture/front” displayed at the bottom in the display order has the smallest first index value among the three target menus. 
     Further, in  FIG. 25 , four participants, “Tadashi YAMADA”, “Ichiro KAWAMURA”, “Misaki GIWA”, and “Ayaka HYANUYASU” are displayed by way of example in the similar manner as  FIG. 8 . In the display field  110 A corresponding to the target menu “chest part/upright imaging posture/front” in the display field  110 B, for example, the icons  115  of all the four participants are displayed. Thus, it is represented that there are the consideration images  26 C captured by the four participants among the consideration images  26 C extracted regarding the target menu “chest part/upright imaging posture/front”. 
     The display state of the consideration image display region  112  is in accordance with the information regarding the staff IDs of the participants and the extraction result  104  of the failed image file. Further, the display state of each of the reference image display region  113  and the reference image candidate display region  114  is in accordance with the search result  105  of the diagnostic image file. Incidentally, the display regions  112  to  114  are blank in the initial display state as shown in  FIG. 25 . 
     An information button  117  for displaying the accompanying information in association with the consideration image  26 C, and a note button  114  in which notes such as a reason of the imaging failure and what the participant says are written are disposed in the upper portion of the consideration image display region  112 . An information button  119  for displaying the accompanying information in association with the consideration image  26 R is disposed in the upper portion of the reference image display region  113  as in the case of the information button  117 . 
     In  FIG. 26 , in the case where the expand button  116  of the desired target menu in the display field  1108  is selected using the cursor  56 , a consideration image selection region  120  appears next to the target menu display region  110 . The target menu of which expand button  116  is selected changes in the color and the pattern as shown by the hatching so as to be distinguished from the other target menus. Here, an example, in which the target menu “chest part/upright imaging posture/front” displayed at the top is selected, is illustrated. 
     The display state of the consideration image selection region  120  is in accordance with the information regarding the staff IDs of the participants, the calculation result  99  of the second index value, and the extraction result  104  of the failed image file. The consideration image selection region  120  consists of a display field  120 A for the icons  115  and a display field  1208  for thumbnails  121  of the consideration images  26 C. Further, a scroll bar  122  used for displaying hidden icons  115  and thumbnails  121  is disposed in the consideration image selection region  120 . 
     The icon  115  in the display field  120 A represents that the consideration image  26 C displayed by the thumbnail  121  in the display field  120 B was captured by the participant corresponding to the icon  15 . Further, the thumbnails  121  are arranged in descending order of the second index value in the display field  1208 . 
     In  FIG. 27 , in the case where a desired thumbnail  121  in the display field  1208  is selected using the cursor  56 , the consideration image selection region  120  disappears. Then, the consideration image  26 C of which thumbnail  121  is selected using the cursor  56 , and the icon  115  which is the same as that in the display field  120 A and corresponds to the consideration image  26 C are displayed in the consideration image display region  112 . Incidentally, among the icons  115  in the participant display region  111 , the icon  115  which is the same as that displayed in the consideration image display region  112  may be highlighted by being blinked, for example. 
     The reference image  26 R is displayed in the reference image display region  113 , and thumbnail  123  of the candidate of the reference image  26 R is displayed in the reference image candidate display region  114 , respectively. The thumbnails  123  in the reference image candidate display region  114  are displayed as the candidates of the reference images  26 R arranged in the upper portion of the reference image candidate display region  114  and the candidates of the reference images  26 R arranged in the lower portion of the reference image candidate display region  114 , among the reference images  26 R in association with the imaging menu which is the same as the target menu of which expand button  116  is selected. The candidates of the reference images  26 R arranged in the upper portion of the reference image candidate display region  114  are associated with a patient different from the imaging target of the consideration image  26 C displayed in the consideration image display region  12 . The candidates of the reference images  26 R arranged in the lower portion of the reference image candidate display region  114  are associated with a patient that is the same as the imaging target of the consideration image  26 C displayed in the consideration image display region  112 . The reference image  26 R to be displayed in the reference image display region  113  can be switched by selecting the thumbnail  123  using the cursor  56 . Incidentally, instead of the candidates of the reference images  26 R associated with a patient different from the imaging target of the consideration image  26 C displayed in the consideration image display region  112 , the reference images  26 R each of which imaging order is the same as that of the consideration image  26 C displayed in the consideration image display region  112  (i.e., the diagnostic images obtained by performing the image capturing again after the consideration image  26 C as the failed image was captured) may be displayed in the upper portion of the reference image candidate display region  114 . 
     As shown in  FIG. 28 , in the case where the information button  117  is selected using the cursor  56 , an accompanying information display region  124  appears in the consideration image display region  112 . Accompanying information associated with the consideration image  26 C (e.g, the file ID, date and time of imaging, patient ID, order ID, tube voltage, tube current, irradiation time, and the like) is displayed in the accompanying information display region  124 . Although not shown in the drawing, in the case where the information button  119  is selected using the cursor  56 , an accompanying information display region for displaying accompanying information associated with the reference image  26 R appears in the reference image display region  113 . In the case where the note button  118  is selected using the cursor  56 , a text input box appears on the conference screen  30 , and thereby it become possible to input a note through the text input box. The inputted note is associated with the consideration image  26 C, and registered in the imaging failure case example DB  21 . 
     An operation of the above configuration is explained hereinbelow by referring to the flowchart in  FIG. 29 . At first, as a preparation for the conference, each of the medical staff members operates the client terminal  12 , and inputs a command for delivering the conference screen  30  through the designation screen  50 . In response to the command for delivering the conference screen  30 , the browser controller  46  generates designation information. Then, as shown in step S 100 , the delivery request for the conference screen  30  containing the designation information is issued from the browser controller  46  to the failed image management server  13 . 
     On the designation screen  50 , it is possible to designate the number of the target menus to be extracted, the number of the consideration images  26 C to be extracted, a calculation target period in which the first index value is calculated, and an extraction target period in which the consideration image  26 C is extracted. Since it becomes possible to designate the number of the target menus, the number of the consideration images, the calculation target period, and the extraction target period as described above, the consideration with the focus on main points can be performed within a limited consideration time. 
     In the failed image management server  13 , a delivery request is received by the receiving unit  71  (step S 200 ). The information regarding the staff IDs of the participants and the information regarding the period in the designation information contained in the delivery request are transmitted to the first calculator  72 . The information regarding the number of target menus is outputted to the first extractor  73 . The information regarding the number of consideration images  26 C and the information regarding the period are outputted to the second extractor  74 . The information regarding the staff IDs of the participants and the information regarding the narrowing-down condition are outputted to the second calculator  75 . The information regarding the staff IDs of the participants is outputted to the screen output controller  76 . 
     The first index value is calculated by the first calculator  72  (step S 210 ). The calculation result  86  of the first index value is outputted to the first extractor  73  and the screen output controller  76 . 
     The first index value is calculated using the first calculation formula xi having the variable Xi based on the number of times of occurrence of imaging failure for each imaging menu and the variable X2 based on the rate of occurrence of imaging failure for each imaging menu. Therefore, the first index value is based on both of the number of times of occurrence of imaging failure for each imaging menu and the rate of occurrence of imaging failure for each imaging menu. Consequently, the first index value makes it possible to know exactly the imaging failure state for each imaging menu. 
     The first calculation formula ΣXi has not only the variables X1 and X2 but also the variables X3, X5, X7, and X9 based on the number of times of occurrence of imaging failure for each imaging menu for each participant and the variables X4, X6, X8, and X10 based on the rate of occurrence of imaging failure for each imaging menu for each participant. Therefore, the first index value is also based on the imaging failure state for each imaging menu for each participant. 
     Further, the first calculation formula ΣXi also has the variable X11 based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same imaging order, and the variable X12 based on the number of times of occurrence of imaging failure for each imaging menu in the image capturing corresponding to the same patient. Therefore, the first index value is also based on the imaging failure state in the image capturing corresponding to the same imaging order and the imaging failure state in the image capturing corresponding to the same patient. 
     In the first extractor  73 , based on the calculation result  86  of the first index value, the designated number of the target menus are extracted (step  3220 ). Specifically, the first extractor  73  extracts the imaging menu as the target menu in order of rank of the first index value from first place, and stops the extraction at the point of time when the number of extracted target menus reaches the designated number. The first extractor  73  outputs the extraction result  91  of the target menus extracted as described above to the second extractor  74  and the screen output controller  76 . 
     In this embodiment, the first index value is summation of the variables Xi as expressed by the first calculation formula ΣXi. Therefore, the first index value is increased as the number of times of occurrence of imaging failure is increased at the same time as the rate of occurrence of imaging failure is increased and as the variables Xi become larger, namely, as the frequency of imaging failure is increased. Concurrently, the rank of the first index value becomes higher. Consequently, the imaging menu having the first index value of which rank is relatively high is an imaging menu of which frequency of imaging failure is relatively high. 
     In this embodiment, since the imaging menu having the first index value of which rank is relatively high is automatically extracted as the target menu by the first extractor  73 , the imaging menu of which frequency of imaging failure is relatively low is extracted and designated. Therefore, there is no fear that useless consideration is performed and results in waste of precious time of the medical staff members, and it becomes possible for the medical staff members to perform the consideration for reliably achieving decrease in the frequency of imaging failure. 
     Further, since the target menu is automatically extracted, it is unnecessary for the medical staff members to know exactly the imaging failure state for each imaging menu in order to extract and designate the imaging menu of which frequency of imaging failure is relatively high. Consequently, it is possible to decrease a burden on each of the medical staff members, such that the medical staff members can sufficiently consider improvement on the image capturing. 
     At the conference, it is preferable that not the radiographic image  26  captured by a person other than the participants but the radiographic image  26  captured by one of the participants is viewed as the consideration image  26 C, because the radiogzaphic image  26  captured by one of the participants is more familiar to the participants and the consideration proceeds. 
     In this embodiment, the imaging failure state of each imaging menu of each participant is taken consideration into the first index value due to the variables X3 to X10 as described above. Therefore, as the number of times of occurrence of imaging failure of the participant is increased at the same time as the rate of occurrence of imaging failure of the participant is increased, the imaging menu has the first index value of which rank is higher, and thus the imaging menu tends to be frequently extracted as the target menu by the first extractor  73 . Consequently, the probability of the radiographic image  26  captured by one of the participants being viewed as the consideration image  26 C is increased. 
     In the case where the image capturing corresponding to the same imaging order or the image capturing corresponding to the same patient fails many times, the necessity of considering improvement on the image capturing is high, in order to prevent repeated failures and prevent increase in the frequency of imaging failure. 
     In this embodiment, the imaging failure state in the image capturing corresponding to the same imaging order and the imaging failure state in the image capturing corresponding to the same patient are taken consideration into the first index value due to the variables X11 and X12 as described above. Therefore, in the case where the image capturing corresponding to the same imaging order or the image capturing corresponding to the same patient fails many times, the imaging menu has the first index value of which rank is higher, and thus the imaging menu tends to be frequently extracted as the target menu by the first extractor  73 . Consequently, the probability of the radiographic image  26  obtained in the failed image capturing corresponding to the same imaging order or the same the patient being viewed as the consideration image  26 C is increased. 
     The second extractor  74  acquires the search result  95  of the failed image file, in which the imaging menu that is the same as the target menu is inputted, from the imaging failure case example DB  21 . The search result  95  is outputted to the second calculator  75 . 
     The second calculator  75  calculates the second index value regarding the failed image file of the search result  95  (step S 230 ). The calculation result  99  of the second index value is outputted to the second extractor  74  and the screen output controller  76 . 
     The second extractor  74  extracts the designated number of the failed image files (consideration images  26 C) based on the calculation result  99  of the second index value (step S 240 ). Specifically, the second extractor  74  extracts the failed image file in order of rank of the second index value from first place, and stops the extraction at the point of time when the number of failed image files reaches the designated number. The extraction result  104  of the failed image file thus extracted is outputted to the screen output controller  76 . 
     The second index value is calculated using the second calculation formula ΣYj having the variable Y1 based on whether or not the failed image f ile of the search result  95  is associated with the participant. Therefore, in the failed image file in which the staff ID that is the same as that of the participant is inputted, the second index value becomes larger, and the rank of the second index value becomes higher. Thus, the failed image file in which the staff ID that is the same as that of the participant is inputted can be preferentially extracted. 
     Further, the second calculation formula ΣYj has the variables Y2 to Y7 corresponding to the narrowing-down condition, in addition to the variable Y1, and therefore the failed image file in which accompanying information corresponding to the narrowing-down condition is inputted has the larger second index value, and the rank of the second index value becomes higher. Thus, the failed image file in which the accompanying information corresponding to the narrowing-down condition is inputted can be preferentially extracted. 
     The search result  105  of the diagnostic image file, in which the imaging menu that is the same as the target menu containing the diagnostic image file having the patient ID that is the same as that of the failed image file of the extraction result  104  is inputted, is acquired as the reference image  26 R by the second extractor  74  from the imaging failure case example DB  21  (step S 250 ). The search result  105  is outputted to the screen output controller  76 . 
     The screen output controller  76  generates the conference screen  30  based on the information regarding the staff IDs of the participants, the calculation result  86  of the first index value, the extraction result  91  of the target menu, the calculation result  99  of the second index value, the extraction result  104  of the failed image file, and the search result  105  of the diagnostic image file. The XML data of the conference screen  30  is outputted from the screen output controller  76  to the client terminal  12  as the requestor of the delivery request (step  3260 ). 
     In the client terminal  12 , the ML data of the conference screen  30  is received by the browser controller  46  (step S 110 ). Based on the XML data, the browser controller  46  reproduces the conference screen  30  to be displayed on the web browser, and the GUI controller  45  displays the conference screen  30  on the display panel  39 A (step  3120 ). 
     On the conference screen  30 , the target menu is displayed in the target menu display region  110 , and the consideration image  26 C is displayed in the consideration image display region  112 . The participants of the conference view the conference screen  30  and consider improvement on the image capturing. 
     In the target menu display region  110 , the target menus are arranged in descending order of the first index value. Further, in the consideration image selection region  120 , the thumbnails  121  of the consideration images  26 C are arranged in descending order of the second index value. In the case where there are two or more target menus or consideration images  26 C, it is possible to easily find and select the target menu or the consideration image  26 C which is highly beneficial in sufficiently decreasing the frequency of imaging failure. 
     The icon  115  representing the individual participant is displayed in the display field  110 A of the target menu display region  110 . The icon  115  is useful in noticing the existence of the consideration image  26 C captured by the participant represented by the icon  115  among the consideration images  26 C extracted regarding the target menu in the display field  110 B, and the icon  115  can be referred to in selecting the target menu. 
     Further, the icon  115  is also displayed in the display field  120 A of the consideration image selection region  12 . The icon  115  is useful in knowing that the consideration image  26 C displayed using the thumbnail  121  in the display field  120 B was captured by the participant represented by the icon  115 , and the icon  15  can be referred to in selecting the consideration image  26 C. 
     Note that, instead of or in addition to displaying the icon  115 , the target menu corresponding to the consideration image  26 C captured by the participant, or the thumbnail  121  of the consideration image  26 C captured by the participant may be displayed distinctively from others. 
     Not only the consideration image  26 C but also the reference image  26 R is displayed on the conference screen  30 . Further, by selecting the information buttons  117  and  119  with use of the cursor  56 , the accompanying information in association with the consideration image  26 C and the accompanying information in association with the reference image  26 P can be displayed, respectively. Therefore, it is possible to compare the consideration image  26 C with the reference image  26 R and compare the accompanying information in association with the consideration image  26 C and the accompanying information in association with the reference image  26 P. For example, after confirmation of the imaging condition in each of the accompanying information in association with the consideration image  26 C and the accompanying information in association with the reference image  26 R, it is possible to give a tutorial on the setting of the imaging condition for the purpose of preventing failure. 
     Note that, a frame-feed button and a frame-reverse button for manually switching the display between the consideration image  26 C and the reference image  26 R may be disposed in the consideration image display region  112  and the reference image display region  113 . The frame feeding may be automatically performed at regular time intervals so as to display the consideration image  26 C in the consideration image display region  112 . In this case, it is preferable that the consideration images  26 C are displayed in descending order of the second index value. 
     In the first embodiment described above, as illustrated by the thumbnails  121  in the display field  120 B of the consideration image selection region  120 , the consideration images  26 C are displayed in accordance with the second index value. However, the arrangement for displaying the consideration images  26 C is not limited thereto. The consideration images  26 C may be displayed with the display size and the display position in accordance with the second index value. 
     Specifically, as in the case of a consideration image selection region  130  shown in  FIG. 30 , each of the thumbnails  121  of the consideration images  26 C is displayed with the display size and the display position in accordance with the second index value. Namely, as the rank of the second index value of the consideration image  26 C represented by the thumbnail  121  is higher, the display size of the thumbnail  121  becomes larger, and as the rank of the second index value of the consideration image  26 C represented by the thumbnail  121  is higher, the display position of the thumbnail  121  becomes nearer to the center of the consideration image selection region  130 . As described above, in the case where each of the consideration images  26 C is displayed with the display size and the display position in accordance with the second index value, the consideration image  26 C having the second index value ranked at relatively high place is selected more frequently due in part to a visual effect. Incidentally, as in the case of the consideration image selection region  120 , the icon  115  may be displayed at the upper portion of the thumbnail  121  or the like. 
     In the first embodiment, based on the second index value calculated by the second calculator  75 , the second extractor  74  determines the failed image as the consideration image  26 C. However, the failed image as the consideration image  26 C may not be determined based on the second index value. In this case, the second calculator  75  is not established in the CPU  37 B, and the second extractor  74  extracts the failed image file of the search result  95  in reverse chronological order of date and time of imaging. Further, the second extractor  74  displays the thumbnails  121  of the consideration images  26 C in reverse chronological order of date and time of imaging in the consideration image selection region  120 . 
     Second Embodiment 
     In the first embodiment, the first calculation formula ΣXi having at least the variable X1 based on the number of times of occurrence of imaging failure for each imaging menu and the variable X2 based on the rate of occurrence of imaging failure for each imaging menu is used to calculate the first index value. However, according to a second embodiment illustrated in  FIG. 31  to  FIG. 38 , the first index value is calculated using the first calculation formula having at least a variable based on an increasing rate of the frequency of imaging failure for each imaging menu. 
     Note that, in the second embodiment, the period designated in the item input region  52  of the designation screen  50  is only the extraction target period. Further, in the second embodiment, the staff  1  of the participant who attends the current conference is described as the current staff ID. 
     In  FIG. 31 , Upon the startup of the failed image management program  70 , a reading/writing (hereinafter abbreviated as R/W) controller  77  is established in the CPU  37 B of the failed image management server  13 , in addition to the respective components  71  to  76  of the first embodiment. 
     The R/W controller  77  controls writing and reading of conference history information  78  stored in the storage device  35 B. The R/W controller  77  outputs the conference history information  78  to the first calculator  72 . 
     The conference history information  78  is information representing the history of the conference held previously. Specifically, as shown in  FIG. 32 , the conference history information  78  consists of summary data  78 A representing the summary of the previous conference and data  78 B on the number of times of occurrence of imaging failure. The date of the previous conference, the staff IDs of the participants who attended the previous conference (hereinafter referred to as previous staff IDs), and the target menu extracted by the first extractor  73  at the previous conference (hereinafter referred to as previous target menu) are inputted in the summary data  78 A. The data  78 B on the number of times of occurrence of imaging failure represents the number of times of occurrence of imaging failure for each imaging menu in a period from the following day of the date of the last but one conference to the previous conference (hereinafter referred to as previous number of times of occurrence of imaging failure). 
     In  FIG. 32 , “2015.02.27” as the date of the previous conference, “R0001, R0004, R0007, R0008” as the previous staff ID, and “chest part/upright imaging posture/front, chest part/upright imaging posture/rear” as the previous target menu are illustrated by way of example. Additionally, as the previous number of times of occurrence of imaging failure, “15” cor responds to the imaging menu “chest part/upright imaging posture/front”, and “30” corresponds to the imaging menu “chest part/upright imaging posture/rear”. 
     In  FIG. 33 , the first calculator  72  outputs the search command designating the period and an imaging failure flag “1” (failed image file) to the imaging failure case example DB  21 . In this case, the period designated by the search command is the period from the following day of the date of the previous conference inputted in the summary data  78 A of the conference history information  78  from the R/W controller  77  to the date on which the delivery request is received by the receiving unit  71 , namely, the date of the current conference (hereinafter referred to as previous-current period). The imaging failure case example DB  21  searches the failed image file, in which the date and time of imaging in the previous-current period is inputted, in response to the search command from the first calculator  72 , and outputs a search result  140  to the first calculator  72 . 
     Note that, in the case where the current conference is a conference held for the first time and the conference history information  78  is not stored in the storage device  35 B, all the failed image files in the imaging failure case example DB  21  are outputted as the search result  140  from the imaging failure case example DB  21  to the first calculator  72 . 
     In  FIG. 33 , the period from “2015.02.28” that is the following day of the date of the previous conference “2015.02.27” shown in  FIG. 32  to “2015.03.27” that is the date of the current conference is illustrated as the previous-current period. Therefore, the search result  140  consists of the failed image files in each of which the date and time of imaging corresponding to the previous-current period “from 2015.02.28 to 2015.03.27” is inputted. 
     In  FIG. 34 , the first calculator  72  generates intermediate process data  141  based on the search result  140 . Specifically, the first calculator  72  focuses attention on the imaging menu of the failed image file of the search result  140 , and counts the number of times of occurrence of imaging failure for each imaging menu based on the number of the failed image files for each imaging menu. For example, in the case of the imaging menu “chest part/upright imaging posture/front”, “40” is counted as the number of times of occurrence of imaging failure. The number of times of occurrence of imaging failure thus counted is the number of times of occurrence of imaging failure for each imaging menu in the previous-current period (hereinafter, referred to as current number of times of occurrence of imaging failure). After counting the current number of times of occurrence of imaging failure, the first calculator  72  outputs the intermediate process data  141  to the R/W controller  77 . 
     In  FIG. 35 , the first calculator  72  further generates intermediate process data  142  based on the conference history information  78  from the R/W controller  77  and the intermediate process data  141 . Specifically, the first calculator  72  registers the previous number of times of occurrence of imaging failure from the data  78 B on the number of times of occurrence of imaging failure of the conference history information  78 , and the current number of times of occurrence of imaging failure from the intermediate process data  141 , respectively in the intermediate process data  142 . Then, the first calculator  72  calculates increment or decrement (abbreviated as “IN. OR DE.” in the drawings) by subtracting the previous number of times of occurrence of imaging failure from the current number of times of occurrence of imaging failure, and divides the increment or decrement by the previous number of times of occurrence of imaging failure, so as to calculate an increasing rate, for each imaging menu. 
     In the case of the imaging menu “chest part/upright imaging posture/front”, for example, the previous number of times of occurrence of imaging failure is “1”, the current number of times of occurrence of imaging failure is “40”, and the increment or decrement obtained by subtracting 15 from 40 equals to “25”, and the increasing rate is expressed by 25/15×100≅167, namely approximately equals to “167%”. In the case of the imaging menu “abdominal part/upright imaging posture/rear” (abbreviated as “A.P./U.I.P./R” in the drawings), the previous number of times of occurrence of imaging failure is “36”, the current number of times of occurrence of imaging failure is “25”, and the increment or decrement obtained by subtracting 36 from 25 equals to “−11”, and therefore the increasing rate is expressed by −11/36×100≅−31, namely approximately equals to “−31%”. 
     Subsequently, the first calculator  72  derives a variable Z1 based on the increasing rate of the number of times of occurrence of imaging failure for each imaging menu in accordance with a table  144  according to increasing rate and variable. 
     The table  144  according to increasing rate and variable is a data table in which the variable corresponding to the increasing rate is registered, and stored in the storage device  35 B, for example. Here, a variable “10” for the increasing rate of 100% or more, a variable “9” for the increasing rate of 90% or more to less than 100%, . . . , a variable “2” for the increasing rate of 20% or ore to less than 30%, and a variable “I” for the increasing rate of 10% or more to less than 20% are registered. Namely, the variable is decreased by one from “10” corresponding to the increasing rate of 100% for every 10%. A variable “0” is registered for the increasing rate of less than 10%. 
     In the case of the imaging menu “chest part upright imaging posture/front”, for example, the increasing rate is “167%”, namely, in the range of 100% or more, and therefore “10” is derived as the variable Z1 and registered in the intermediate process data  142 . In the case of the imaging menu “abdominal part/upright imaging posture rear”, the increasing rate is “−31%”, namely in the range of less than 10%, and therefore “0” is derived as variable Z1 and registered in the intermediate process data  142 . 
     Further, the first calculator  72  also derives a variable Z2 based on the increasing rate of the number of times of occurrence of imaging failure of the previous target menu in the summary data  78 A of the conference history information  78  in accordance with the table  144  according to increasing rate and variable. The first calculator  72  derives the variable Z2 only for the imaging menu corresponding to the previous target menu among the imaging menus. Incidentally, how to derive the variable Z2 is the same as that of the variable Z1. 
     In  FIG. 35 , as the previous target menu, “chest part/upright imaging posture/front, chest part/upright imaging posture/rear”, which is the same as that in  FIG. 32 , is illustrated. As the variable Z2 of the imaging menu “chest part/upright imaging posture/front” corresponding to the previous target menu, “10” is derived as in the case of the variable Z1, and registered in the intermediate process data  142 . Further, as the variable Z2 of the imaging menu “chest part/upright imaging posture/rear”, “3” is derived as in the case of the variable Z1, and registered in the intermediate process data  142 . Regarding the imaging menus “abdominal part/upright imaging posture/front” and “abdominal part/upright imaging posture/rear”, each of which does not correspond to the previous target menu, the variable Z2 is not derived as shown by diagonal lines in the drawing, and not registered. 
     Further, the first calculator  72  also derives a variable  23  regarding the imaging menu which is not extracted as the previous target menu. The first calculator  72  derives the variable Z3 only for the imaging menu which does not correspond to the previous target menu among the imaging menus. 
     In  FIG. 35 , “5” is registered as the variable Z3, without exception, for the imaging menus “abdominal part/upright imaging posture/front” and “abdominal part/upright imaging posture/rear” each of which does not correspond to the previous target menu. The variable  23  is not derived for the imaging menus “chest part/upright imaging posture/front” and “chest part upright imaging posture/rear” each of which corresponds to the previous target menu as shown by diagonal lines in the drawing, and not registered. 
     In  FIG. 36 , the first calculator  72  receives the information regarding the current staff ID from the receiving unit  71 . The first calculator  72  generates intermediate process data  143  based on the information regarding the current staff IDs, the information regarding the previous staff IDs and the previous target menu which is inputted in the summary data  78 A of the conference history information  78  of the P/W controller  77 , and the search result  140 . 
     Specifically, the first calculator  72  focuses attention on the imaging menu of the failed image file of the search result  140  and the staff IDs, and counts the number of times of occurrence of imaging failure of the imaging menu corresponding to the previous target menu based on the imaging menu corresponding to the previous target menu and the number of failed image files in each of which the staff ID as both of the previous staff ID and the current staff ID is inputted. 
     The participant having the staff ID as both of the previous staff ID and the current staff ID is a participant who attended the previous conference and is designated to attend the current conference (hereinafter, referred to as consecutive participant). The number of times of occurrence of imaging failure thus counted is the number of times of occurrence of imaging failure for the imaging menu corresponding to the previous target menu made by the consecutive participant in the previous-current period. 
     After counting the number of times of occurrence of imaging failure, the first calculator  72  derives a variable  24  based on whether or not the consecutive participant failed in the image capturing of the previous target menu. Here, as the variable Z4, a numerical value that is equal to the counted number of times of occurrence of imaging failure is derived. The first calculator  72  derives the variable Z4 only for the imaging menu corresponding to the previous target menu among the imaging menus. 
     In  FIG. 36 , as the current staff IDs, the staff IDs “R0001”, “R0002”, “R0005”, and “R0008” are illustrated in the same manner as in  FIG. 9 . Additionally, as the previous staff IDs, the staff IDs “R0001”, “R0004”, “R0007”, and “R0008” which are the same as those in  FIG. 32  are illustrated, and as the previous target menu, the imaging menu “chest part/upright imaging posture/front, chest part/upright imaging posture/rear” which is the same as that in  FIG. 32  is illustrated. The staff  10  as both of the previous staff ID and the current staff ID is “R0001” and “R0008”. 
     Further,  FIG. 36  illustrates the case where there are three failed image files in each of which the imaging menu “chest part/upright imaging posture/front” corresponding to the target menu and the staff ID “0001” or “R0008” are inputted, and one failed image file in which the imaging menu “chest part/upright imaging posture/rear” corresponding to the target menu and the staff ID “R0008” are inputted, in the search result  140 . 
     In this case, “3” is registered as the number of times of occurrence of imaging failure in the item of the imaging menu “chest part/upright imaging posture/front” in the intermediate process data  143 , and “1” is registered as the number of times of occurrence of imaging failure in the item of the imaging menu “chest part/upright imaging posture/rear” in the intermediate process data  143 , respectively. Additionally, “3” is derived and registered as the variable  24  for the imaging menu “chest part/upright imaging posture/front”, and “1” is derived and registered as the variable Z4 for the imaging menu “imaging menu “chest part/upright imaging posture/rear”, respectively. An item is not provided for the imaging menu which does not correspond to the previous target menu in the intermediate process data  143 , and therefore the variable Z4 is not derived and not registered. 
     In  FIG. 37 , the first calculator  72  reads out each variable Zk (k=1 to 4) from each of the intermediate process data  142  and  143 . The first calculator  72  calculates the first index value for each imaging menu using a first calculation formula ΣZk for obtaining summation of the variables Zk. The first calculator  72  outputs a calculation result  146  of the first index value to the first extractor  73  and the screen output controller  76 . 
     The first index value may be calculated by adding or multiplying an adequate weighting coefficient to each variable Zk. For example, “10” is added to the variable Z1 based on the increasing rate of the number of times of occurrence of imaging failure for each imaging menu. Alternatively, the variable Z4 based on whether or not the consecutive participant failed in the image capturing corresponding to the previous target menu is multiplied by “2”. In this case, the weighting coefficient may be configured to be settable on the client terminal  12 . 
     The subsequent process is approximately the same as that of the above first embodiment, and therefore only the difference in the process between this embodiment and the above first embodiment is described hereinbelow. 
     Firstly, the first extractor  73  adds the extraction result  91  of the extracted target menu to the second extractor  74  and the screen output controller  76 , and outputs it to the R/W controller  77 . 
     Further, as shown in  FIG. 38 , the R/W controller  77  receives the information regarding the current staff ID from the receiving unit  71 , the intermediate process data  141  of the current number of times of occurrence of imaging failure from the first calculator  72 , and the extraction result  91  of the target menu from the first extractor  73 . The R/W controller  77  updates the conference history information  78  based on the information regarding the current staff IDs, the intermediate process data  141 , and the extraction result  91 . 
     Specifically, the R/W controller  77  rewrites the date of the previous conference in the summary data  78 A to the date on which the deliver y request was received by the receiving unit  71 , namely, the date of the current conference, rewrites the previous staff IDs to the current staff IDs received from the receiving unit  71 , and rewrites the previous target menu to the target menu of the extraction result  91 . Further, the R/W controller  77  replaces the data  78 B on the number of times of occurrence of imaging failure with the intermediate process data  141 . 
     According to this embodiment, the first index value is calculated using the first calculation formulas ΣZk having the variable Z1 based on the increasing rate of the number of times of occurrence of imaging failure for each imaging menu. Therefore, the first index value is based on the increasing rate of the number of times of occurrence of imaging failure for each imaging menu. Consequently, the first index value makes it possible to know exactly the imaging failure state for each imaging menu. 
     The first calculation formula ΣZk has not only the variable Z1 but also the variable Z2 based on the increasing rate of the number of times of occurrence of imaging failure of the previous target menu. Therefore, the first index value is based on the imaging failure state of the previous target menu in the previous-current period. 
     Further, the first calculation formula ΣZk also has the variable Z3 regarding the imaging menu which was not extracted as the previous target menu. Therefore, the first index value is also based on the imaging menu which does not correspond to the previous target menu. 
     Furthermore, the first calculation formula ΣZk has the variable Z4 based on whether or not the consecutive participant failed in the image capturing of the previous target menu. Therefore, the first index value is also based on whether or not the consecutive participant failed in the image capturing of the imaging menu corresponding to the previous target menu in the previous-current period. 
     According to this embodiment, the first index value is the summation of the variables Zk as expressed by the first calculation formula ΣZk. Therefore, as the increasing rate of the number of times of occurrence of imaging failure is higher and the variable Zk is larger, namely, as the increasing rate of the frequency of imaging failure is higher, the first index value is increased and the first index value is ranked at higher place. Consequently, the imaging menu having the first index value of which rank is relatively high is an imaging menu of which increasing rate of the frequency of imaging failure is relatively high. 
     According to this embodiment, since the imaging menu having the first index value of which rank is relatively high is automatically extracted as the target menu by the first extractor  73 , the imaging menu of which increasing rate of the frequency of imaging failure is relatively low is extracted and designated. Therefore, there is no fear that useless consideration is performed and results in waste of precious time of the medical staff members, and it becomes possible for the medical staff members to perform the consideration for reliably suppressing the increase in the frequency of imaging failure. 
     Further, since the target menu is automatically extracted, it is unnecessary for the medical staff members to know exactly the imaging failure state for each imaging menu in order to extract and designate the imaging menu of which increasing rate of the frequency of imaging failure is relatively high. Consequently, it is possible to decrease a burden on each of the medical staff members, such that the medical staff members can sufficiently consider improvement on the image capturing. 
     In the case where the increasing rate of the number of times of occurrence of imaging failure of the previous target menu extracted at the previous conference becomes relatively lower at the current conference, it is represented that the consideration at the previous conference was useful and the imaging skill for the previous target menu has been improved. In contrast, in the case where the increasing rate of the number of times of occurrence of imaging failure of the previous target menu extracted at the previous conference becomes relatively higher at the current conference, it is represented that the consideration at the previous conference was not sufficient and the imaging skill for the previous target menu has not been improved yet. 
     In the case where the increasing rate of the number of times of occurrence of imaging failure of the previous target menu becomes relatively higher at the current conference, it is preferable that the previous target menu is extracted as the target menu also at the current conference and the radiographic image  26 , which was obtained by the failed image capturing of the imaging menu corresponding to the previous target menu is viewed as the consideration image  26 C, because the consideration can be consecutively performed from the previous conference and the improvement on the image capturing can be studied again. 
     In this embodiment, the first index value is based on the imaging failure state of the previous target menu in the previous-current period using the variable Z2 as described above. Therefore, the previous target menu, in which the increasing rate of the number of times of occurrence of imaging failure is relatively high, has the first index value ranked at higher place, and tends to be frequently extracted as the target menu by the first extractor  73 . Consequently, the probability of the radiographic image  26  obtained by the failed image capturing of the imaging menu corresponding to the previous target menu being viewed as the consideration image  26 E is increased. 
     In contrast, in the case where the increasing rate of the number of times of occurrence of imaging failure of the previous target menu becomes relatively lower at the current conference, it is preferable that not the previous target menu but the imaging menu which does not correspond to the previous target menu is extracted as the target menu and the radiographic image  26  obtained by the failed image capturing of the imaging menu which does not correspond to the previous target menu is viewed as the consideration image  26 C at the current conference, because it is possible to prevent the increase in the frequency of imaging failure for each imaging menu equally for each imaging menu. 
     In this embodiment, the first index value is based on the imaging menu which does not correspond to the previous target menu using the variable Z3 as described above. Therefore, in the case where the increasing rate of the number of times of occurrence of imaging failure of the previous target menu becomes relatively lower at the current conference, the imaging menu which does not correspond to the previous target menu has the first index value ranked at higher place, and tends to be extracted frequently as the target menu by the first extractor  73 . Consequently, the probability of the radiographic image  26  obtained by the failed image capturing of the imaging menu which does not correspond to the previous target menu being viewed as the consideration image  26 C is increased. 
     Further, in the case where the consecutive participant failed in the image capturing of the imaging menu corresponding to the previous target menu in the previous-current period, it is represented that the consideration at the previous conference was not sufficient and the imaging skill of the consecutive participant has not been improved yet. 
     In such a case, in order to prevent a situation that the consecutive participant repeats the failure hereafter and the increasing rate of the frequency of imaging failure s increased, the necessity of considering improvement on the image capturing is high. Therefore, it is preferable that the radiographic image  26  obtained in the failed image capturing of the imaging menu corresponding to the previous target menu by the consecutive participant in the previous-current period is viewed as the consideration image  26 C. 
     In this embodiment, the first index value is based on whether or not the consecutive participant failed in the image capturing of the imaging menu corresponding to the previous target menu in the previous-current period using the variable Z4 as described above. Therefore, the previous target menu, for which the number of times of occurrence of imaging failure made by the consecutive participant in the previous-current period is larger, has the first index value ranked at higher place, and tends to be extracted frequently as the target menu by the first extractor  73 . Consequently, the probability of the radiographic image  26  obtained by the failed image capturing of the imaging menu corresponding to the previous target menu by the consecutive participant in the previous-current period being viewed as the consideration image  26 C is increased. 
     Further, also in this embodiment, as in the case of the above first embodiment, the target menus are arranged in descending order of the first index value in the target menu display region  110 . Furthermore, the thumbnails  121  of the consideration images  26 C are arranged in descending order of the second index value in the consideration image selection region  120 . In the case where there are two or more target menus or consideration images  26 C, it is possible to easily find and select the target menu or the consideration image  26 C which is highly beneficial in sufficiently suppressing the increasing rate of the frequency of imaging failure. 
     Third Embodiment 
     Note that, in the case where there are no staff IDs of the participants (referred to as current staff IDs in the second embodiment) in the failed image file of the search result  95  searched by the second extractor  74  based on the target menu, it turns out that the consideration images  26  all of which were captured by a person other than the participants are viewed. As described above, at the conference, not the radiographic image  26  captured by a person other than the participants but the radiographic image  26  captured by the participant is preferably viewed as the consideration image  26 C, and therefore it is not a preferable situation that the consideration images  26 C all of which were captured by a person other than the participants are viewed. 
     Accordingly, in this embodiment, in the case where there are no staff IDs of the participants in the failed image file of the search result  95 , the second extractor  74  replaces the target menu with another one to search the failed image file again. Until the failed image file in which the staff ID of the participant is inputted is retrieved, the replacement of the target menus and the search for the failed image file are repeated. 
     In this case, the receiving unit  71  outputs the information regarding the staff IDs of the participants to the second extractor  74 . As illustrated in step S 500  of  FIG. 39 , the second extractor  74  receives the information regarding the staff IDs of the participants from the receiving unit  71 . As with the case shown in  FIG. 19 , the second extractor  74  searches the failed image file, in which the imaging menu that is the same as the target menu is inputted, from the imaging failure case example DE  21  (step S 510 ). Then, the second extractor  74  compares the staff ID inputted in the searched failed image file with the staff IDs of the participants received from the receiving unit  71  (step S 520 ). 
     As a result of the comparison, there are no failed image files, in each of which the staff IDs of the participants are inputted, among the searched failed image files (NO in step S 530 ), the target menu used to search the failed image file in step S 510  is replaced with another target menu (step S 540 ). Thereafter, the new target menu is used to search the failed image file again in step S 510 . 
     Until the failed image file in which the staff ID of the participant is inputted is retrieved (YES in step S 530 ), the second extractor  74  repeats the replacement of the target menus in step S 540  and the search for the failed image file in step S 510 . 
     The target menu replaced by the second extractor  74  is an imaging menu having the first index value ranked at first place among the imaging menus which were not extracted as the target menu by the first extractor  73 , for example. By referring to  FIG. 18  as an example, in the case where there is no staff ID of the participant in the failed image file in which the imaging menu “chest part/upright imaging posture/front” having the first index value ranked at first place is inputted, the imaging menu is replaced with the imaging menu “cephalic part/sitting imaging posture/front” having the first index value ranked at second place, and the failed image file is searched again. In the case where there is no staff ID of the participant in the searched failed image file in which the imaging menu “cephalic part/sitting imaging posture/front” having the first index value ranked at second place is inputted, the imaging menu is replaced with the imaging menu “abdominal part/upright imaging posture/rear” having the first index value ranked at third place, and the failed image file is searched again. 
     As a result, since there is inevitably the radiographic image  26  captured by the participant as the consideration image  26 C, it is possible to avoid the situation that the consideration images  26 C all of which were captured by a person other than the participants are viewed. Incidentally, in this case, there is a fear that the imaging menu having the first index value ranked at relatively lower place is retrieved as the target menu as a result of the replacement of the target menus, and therefore a mark for indicating that the target menu is a replaced one may be displayed in the display field  110 B of the target menu display region  110 , for example, so as to draw participant&#39;s attention. 
     Forth Embodiment 
     In the case where there are two or more target menus extracted by the first extractor  73 , in comparison between the target menu having the first index value ranked at relatively higher place and the target menu having the first index value ranked at relatively lower place, the frequency of imaging failure or the increasing rate of the frequency of imaging failure is higher and the imaging failure state is poor in the target menu having the first index value ranked at relatively higher place. Therefore, the consideration image  26 C of the target menu having the first index value ranked at relatively higher place is preferably viewed, such that the effect of decreasing the frequency of imaging failure or suppressing the increase in the frequency of imaging failure is achieved. 
     Accordingly, in this embodiment, the number of the consideration images  260  to be extracted by the second extractor  74  is increased for the failed image file corresponding to the target menu having the first index value ranked at relatively higher place and worse imaging failure state. 
     In this case, the second extractor  74  generates intermediate process data  145  shown in  FIG. 40 . An allocation rate of the number of the failed image files to be extracted as the consideration images  260  (the number of the consideration images  26 C to be extracted) for each of three target menus  1 ,  2 , and  3 , for example, is calculated based on the first index value and registered in the intermediate process data  145 . Incidentally, the target menu  1  has the first index value of “100” ranked at first place, the target menu  2  has the first index value of “70” ranked at second place, and the target menu  3  has the first index value of “30” ranked at third place. 
     The allocation rate of the number of the failed image files to be extracted as the consideration image  26 C is calculated by dividing the first index value of each of the target menus  1  to  3  by summation of the first index values of the target menus  1  to  3 . In this case, the first index value of each of the target menus  1  to  3  is “100, “70”, and “30”, respectively, and the summation of the first index values of the target menus  1  to  3  is expressed by 100+70+30, namely equals to 200. Accordingly, the allocation rate for the target menu  1  is expressed by (100/200)×100, namely equals to 50%. In the similar manner, the allocation rate for the target menu  2  is 35%, and the allocation rate for the target menu  3  is 15%. 
     In the case where “100” is designated as the number of the consideration images  26 C on the designation screen  50 , as shown in  FIG. 40 , the number of the consideration images  260  to be extracted for the target menu  1  is expressed by 100×0.5, namely equals to “50”. In the similar manner, the number of the consideration images  26  to be extracted for the target menu  2  is “35”, and the number of the consideration images  26 C to be extracted for the target menu  3  is “15”. 
     The second extractor  74  extracts the failed image file of each of the target menus  1  to  3  based on the intermediate process data  145 . Thus, for the target menu in which the frequency of imaging failure can be decreased, or for the target menu in which the increase in the frequency of imaging failure can be suppressed, the number of the consideration images  26 C to be extracted becomes larger, and therefore it is possible to perform meaningful consideration and promote the decrease in the frequency of imaging failure or the suppression of the increase in the frequency of imaging failure. 
     The number of consideration image  26 C to be extracted is not necessarily calculated based on the first index value. For example, in the case where the number of target menus extracted by the first extractor  73  is “9”, and “45” is designated as the number of consideration images  26 C on the designation screen  50 , the number of the consideration images  26 C to be extracted for the target menu having the first index value ranked at first place may be set to “9”, the number of the consideration images  26   e  to be extracted for the target menu having the first index value ranked at second place may be set to “8”, . . . , the number of the consideration images  26 C to be extracted for the target menu having the first index value ranked at eighth place may be set to “2”, and the number of the consideration images  26 C to be extracted for the target menu having the first index value ranked at ninth place may be set to “1”, namely, the number of the consideration images  26 C to be extracted may be decreased by one as the rank of the first index value is decreased. Further, in the case where the number of the target menus is two, the allocation rate for the target menu having the first index value ranked at first place may beset to 70%, and the allocation rate for the target menu having the first index value ranked at second place may be set to 30%, namely the allocation rate may be preliminarily set in accordance with the number of the target menus. 
     Note that, as shown in  FIG. 41 , a check box  150  for designating a particularly notable participant may be disposed next to the icon  115  of each participant in the participant display region  111  of the conference screen  30 . In the case where the check box  150  is selected using the cursor  56 , the extraction of the target menu and consideration image  26 C may be performed by the failed image management server  13  again. 
     In this case, in the failed image management server  13 , at the time of calculating the first index value by the first calculator  72 , a weighting coefficient that is more than 0 is added to the variable based on the number of times of occurrence of imaging failure and the variable based on the rate of occurrence of imaging failure of the participant of which check box  150  is selected using the cursor  56 . Alternatively, the variable based on the number of times of occurrence of imaging failure and the variable based on the rate of occurrence of imaging failure of the participant of which check box  150  is selected using the cursor  56  are multiplied by a weighting coefficient more than. In  FIG. 41 , the check box  150  corresponding to “Ayaka HYAKUYASU” having the staff ID “R0001” is selected, and therefore a weighting coefficient more than 0 is added to the variable X9 based on the number of times of occurrence of imaging failure and the variable X10 based on the rate of occurrence of imaging failure corresponding to the staff ID “P0008” shown in  FIG. 14 , or the variables X9 and X10 are multiplied by a weighting coefficient more than 1. Alternatively, a weighting coefficient more than 0 is added to the variable Z4 of the imaging menus “chest part/upright imaging posture/front” and “chest part/upright imaging posture/rear” shown in  FIG. 36  or the variable Z4 is multiplied by a weighting coefficient more than 1. 
     Furthermore, when the second calculator  75  calculates the second index value, a weighting coefficient more than 0 is added to the variable Y1 regarding the participant of the failed image file, in which the staff ID of the participant of which check box  150  is selected using the cursor  56  is inputted, or the variable Y1 is multiplied by a weighting coefficient more than 1. 
     As described above, the target menu and the consideration image  26 C are extracted again such that the contribution ratio of the variable regarding the participant of which check box  150  is selected using the cursor  56  to the first index value and the second index value is increased. Thereby, probability of the imaging menu that the participant of which check box  150  was selected using the cursor  56  failed in the image capturing, and the failed image captured by the participant of which check box  150  was selected using the cursor  56  being extracted as the target menu and the consideration image  26 C is increased, respectively. 
     For example,  FIG. 42  illustrates a display state of the target menu display region  110  before and after selection of the check box  150 . In this case, before the check box  150  corresponding to “Ayaka HYAUYASU” is selected, the target menu containing the consideration image  26 C captured by “Ayaka HYAKUYASU” is not displayed in the target menu display region  110 . In contrast, after the selection of the check box  150  corresponding to “Ayaka HYAKUYASU”, the contribution ratio of the variable regarding “Ayaka HYAKUYASU” to the first index value is increased, and thereby the target menu “abdominal part/upright imaging posture/front” containing the consideration image  26 C captured by “Ayaka HYAKUYASU” is displayed at the top of the target menu display region  110 . 
     Further, for example,  FIG. 43  illustrates a display state of the consideration image selection region  120  before and after the selection of the check box  150 . In this case, before the check box  150  corresponding to “Ayaka HYAKUYASU” is selected, the thumbnail  121  of the consideration image  26  captured by “Ayaka HYAKUYASU” is not displayed in the consideration image selection region  120 . In contrast, after the selection of the check box  150  corresponding to “Ayaka HYAKUYASU”, the contribution ratio of the variable regarding “Ayaka HYAKUYASU” to the second index value is increased, and thereby a series of three thumbnails  121  of the consideration images  26  captured by “Ayaka HYAKUYASU” are displayed from the top in the consideration image selection region  120 . 
     Note that, a function of the check box  150  for designating the particularly notable participant may be provided in the participant selection region  51  of the designation screen  50 . However, it is preferable that the check box  150  is provided in the participant display region  111  of the conference screen  30  as shown in  FIG. 41 , because it is possible to promptly respond to the case where the failed image corresponding to the particularly notable participant is required to be considered in the middle of the conference, thus resulting in high convenience. 
     In the above first embodiment, the narrowing-down condition is used only for the calculation of the second index value. However, the narrowing-down condition may be contained in the search command at the time of searching the diagnostic image file and the failed image file by the first calculator  72  as shown in  FIG. 11 , at the time of searching the failed image file by the second extractor  74  as shown in  FIG. 19 , and at the time of searching the diagnostic image file by the second extractor  74  as shown in  FIG. 23 . 
     It is sufficient that the first calculation formula has at least the variable X1 based on the number of times of occurrence of imaging failure for each imaging menu and the variable X2 based on the rate of occurrence of imaging failure for each imaging menu, or the variable Z1 based on the increasing rate of the frequency of imaging failure for each imaging menu. Further, it is sufficient that the second calculation formula has at least the variable Y1 based on whether or not the failed image as the consideration image  26 C is associated with the participant. 
     The first calculation formula and the second calculation formula are not limited to the summation ΣXi of the variables Xi, the summation ΣYj of the variables Yj, and the summation ΣZk of the variables Zk, as described in the first and second embodiments by way of example. For example, an infinite product ΠXi of the variables Xi, an infinite product ΠYj of the variables Yj, and an infinite product ΠZk of the variables Zk may be used. Further, the variable Xi becomes larger as the number of times of occurrence of imaging failure is increased or as the rate of occurrence of imaging failure is increased in each of the above embodiments. However, in contrast, the variable Xi may be larger as the number of times of occurrence of imaging failure is decreased or as the rate of occurrence of imaging failure is decreased. In the similar manner, the variable Zk may be larger as the increasing rate of the frequency of imaging failure or the like is decreased. 
     Various modifications are possible for the hardware configuration of the computer constituting the failed image management server  13  corresponding to the failed image management apparatus of the present invention. For example, the failed image management server  13  may consist of a plurality of server computers separated as the hardware, for the purpose of improving ability of processing and reliability. 
     Specifically, the functions of the receiving unit  71 , the first calculator  72 , and the first extractor  73 , and the functions of the second extractor  74 , the second calculator  75 , and the screen output controller  76  are dispersedly assumed by two server computers. In this case, the two server computers constitute the failed image management system. The server computer having the functions of the receiving unit  71 , the first calculator  72 , and the first extractor  73  outputs the calculation result.  86  of the first index value and the extraction result  91  of the target menu to the server computer having the functions of the second extractor  74 , the second calculator  75 , and the screen output controller  76 . 
     Further, all the functional components  71  to  76  may be established in the CPU  37 A of the client terminal  12 , such that the client terminal  12  operates as the failed image management apparatus. Alternatively, part of the functional components  71  to  76  may be established in the CPU  37 A of the client terminal  12 . In this case, the client terminal  12  and the failed image management server  13  constitute the failed image management system. 
     In the case where all the functional components  71  to  76  are established in the CPU  37 A of the client terminal.  12 , the client terminal  12  issues search requests corresponding to the search command of the diagnostic image file and the failed image file shown in  FIG. 1 , the search command of the failed image file shown in  FIG. 19 , and the search command of the diagnostic image file shown in  FIG. 23 , to the failed image management server  13 . The failed image management server  13  outputs the search results  80 ,  95 , and  105  to the client terminal  12  in response to the search requests. 
     The receiving unit  71  established in the CPU  37 A of the client terminal  12  receives the search results  80 ,  95 , and  105  from the failed image management server  13 , and receives the delivery command from the GUI controller  45 . Further, the screen output controller  76  established in the CPU  37 A of the client terminal  12  generates the conference screen  30 , and outputs the generated conference screen  30  to the GUI controller  45 . 
     Alternatively, the imaging failure case example DB  21  may be established in the PACS  11 , such that the PACS  11  manages not only the diagnostic image file but also the failed image file and the PACS  11  assumes the function of the failed image management apparatus. 
     As described above, the hardware configuration of the computer may be appropriately changed in accordance with the required properties such as the ability of processing, safety, and reliability. Further, as a matter of course, not only the hardware but also the application programs such as the failed image management program  70  may be duplicated or dispersedly stored in a plurality of storage devices, for the purpose of securing the safety and reliability. 
     The means for providing the target menus and the consideration images  26   c  to the medical staff members is not limited to the delivery of the conference screen  30  using the web described in each of the above embodiments. For example, a DB for storing a consideration file in which the target menus and the consideration images  26 C are recorded may be provided, and the access authority to the DB may be given to the medical staff members, such that each of the medical staff members reads out the consideration file from the DB. A publicly-known file transfer protocol such as FTPS (File Transfer Protocol over SSL/TLS) may be used to automatically transmit the consideration file to the client terminal  12 . Instead of the file transfer protocol, e-rail may be used. Further, a paper material on which the target menus and the consideration images  26 C are printed may be outputted. 
     According to each of the above embodiments, the medical information system  2  established in one medical facility is described by way of example, and the failed image management server  13  is used in one medical facility. However, the failed image management server  13  may be used in a plurality of medical facilities. 
     According to each of the above embodiments, the client terminal  12  installed in one medical facility is communicably connected to the failed image management server  13  using the network  14  such as the LAN, such that various functions in response to various requests from the client terminal  12  are provided. For the purpose of using the various functions in a plurality of medical facilities, the failed image management server  13  is communicably connected to the client terminals  12  installed in a plurality of medical facilities using WAN (Wide Area Network) such as the internet and public telecommunication network. Then, the request from each of the client terminals  12  in a plurality of medical facilities is received by the failed image management server  13  using the WAN, and various functions are provided to each of the client terminals  12 . Incidentally, in the case of using the WAN, by taking the information security into consideration, it is preferable that VPN (Virtual Private Network) is established, or a communication protocol at a high security level such as HTTPS (Hypertext Transfer Protocol Secure) is used. 
     In this case, the failed image management server  13  may be installed in and managed by a data center managed by a company independent from the medical facility or one of the medical facilities. 
     Although the radiographic image captured by the radiation imaging system  10  is exemplified as the medical image in each of the above embodiments, the medical image may be an MRI image captured by an MRI imaging system or the like. Further, the radiographic image  26  and the accompanying information are not necessarily organized in a file format in the similar manner as the image file. Furthermore, it is described that one diagnostic image f ile corresponds to one imaging order, however a plurality of diagnostic image files may correspond to one imaging order. 
     Furthermore, although the failed image file and the diagnostic image file are stored in one imaging failure case example DB  21 , a DB for storing the failed image file and a DB for storing the diagnostic image file may be separately provided. 
     According to the above first embodiment, as the situation of the consideration, the conference at which a plurality of the medical staff members gather is exemplified. However, as a matter of course, the present invention is also applicable to personal consideration by one medical staff member. In this case, the client terminal  12  is preferably a portable terminal such as a mobile phone, smartphone, tablet, PDA (Personal Digital Assistant), and laptop. Thereby, regardless of date, time, and place, consideration can be repeatedly performed, and spare time such as a time interval between image capturing operations and commuting hours can be used for the consideration. 
     Although the present invention has been fully described by way of the preferred embodiments thereof with reference to the accompanying drawings, various changes and modifications will be apparent to those having skill in this field. Therefore, unless otherwise these changes and modifications depart from the scope of the present invention, they should be construed as included therein.