Patent Publication Number: US-2022233158-A1

Title: X-ray fluoroscopic imaging apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application relates to, and claims priority from, Ser. No.:JP2021-008695 filed Jan. 22, 2-21, the entire contents of which are incorporated herein by reference. 
     FIGURE FOR PUBLICATION 
       FIG. 3 . 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an X-ray fluoroscopic imaging apparatus that performs an X-ray imaging in multiple directions by rotating the X-ray tube and the X-ray detector in the body axis direction and around the body axis of a subject while being supported to be facing each other. 
     Description of the Related Art 
     When a procedural operation or a medical examination using a catheter procedure is performed in the medical field, e.g., in a circulatory field including such as cardiovascular disorder, the X-ray fluoroscopic imaging apparatus that performs an X-ray fluoroscopy or an X-ray imaging is now mandatory, In such a procedural operation, the fluorescence imaging is performed by irradiating the circulatory region of the subject with the X-ray in an arbitrary direction. The operator performs the procedural operation by operating the arbitrarily the catheter referring to the X-ray image data acquired using the fluoroscopic imaging. 
     The X-ray fluoroscopic imaging apparatus comprises an imaging system consisting of a table on which the subject is loaded, an X-ray tube and an X-ray detector and a C-shape arm (C-arm) supporting the imaging system. The X-ray tube and the X-ray detector are installed to one end and the other end respectively of the C-arm and the C-ram is set to allow the X-ray tube and the X-ray detector to face each other while sandwiching the subject. The C-arm is rotatable in the body axis direction and the circumference direction of the body axis of the subject (here in after “rotation direction”) with a predetermined rotation angle, The C-arm enables rotating to an arbitrary rotation position (in the arbitrary rotation direction and with the arbitrary angle), so that the X-ray imaging can be performed from multiple directions relative to the target region (region of interest) of the subject. 
     It is disclosed that a conventional X-ray fluoroscopic imaging apparatus has a function (auto-positioning function) with which the predetermined rotation position is linked to the memory switch and stored therein, and the C-arm thereof is shifted to such a memorized rotation position at an arbitrary timing (e.g., refer to the Patent Document) 1). The conventional X-ray fluoroscopic imaging apparatus having the auto-positioning function comprises a console equipped with a memory execution switch, a rotation execution switch and a plurality of memory switches. 
     For example, the operation in which the rotation position is memorized in correspondence with the memory switch runs pushing down the first memory switch and then memory execution switch in the state in which the C-arm is being shifted to the predetermined rotation position. In accordance with the operation of the memory execution switch, the information of the rotation position of the C-arm at the present time is stored while linking to the first memory switch. And the information of the respective different rotation positions with regard to a plurality of memories is stored while linking thereto for a long period of time by running the same operation on the second memory switch and subsequently therefrom. 
     When the C-arm is shifted to the desired rotation position, the C-arm automatically shifts due to the operation of the rotation execution switch following selecting and then pushing down the memory switch linked to the information of such a rotation position. The C-arm can be quickly rotated to a plurality of rotation positions corresponding to the number of the memory switches due to such an auto-positioning function. 
     RELATED PRIOR ART 
     Patent Document 
     Patent Document 1—WO 2007/091295 A1 
     ASPECTS AND SUMMARY OF THE INVENTION 
     Objects to be Solved 
     Nevertheless, in the case of a conventional example having such structure, following problems are remained to be solved. 
     As a recent trend, the C-arm is shifted to a number of the rotation positions when proceeding the procedural operation and the X-ray images are acquired by irradiating X-rays from a number of rotation positions. In addition, as a trend, the procedural operations is performed for a larger number of the subjects using the X-ray fluoroscopic imaging apparatus. As a result, the number of rotation positions to be stored would become vast. 
     According to the conventional X-ray fluoroscopic imaging apparatus, the number of memory switches corresponding to the number of rotation positions to be stored is needed. Therefore, provided the number of rotation positions to be stored becomes vast, the number of the memory switches becomes also vast. Whereas the scope of the operation board is limited, and it is difficult that a vast number of the memory switches are in place on the operation board, accordingly. On the other hand, it is ideal to make the respective memory switches smaller to place the vast number of the memory switches on the operation board, but the memory switch should have the size larger than a certain size while considering operability of the memory switch. Accordingly, a support with miniaturization of the memory switch is limited. 
     The present invention is accomplished considering such circumstances and the object of the present invention is to provide an X-ray fluoroscopic imaging apparatus capable of suppressing increase of the number of memory switches and performing an auto-positioning for a larger number of rotation positions. 
     Means for Solving the Problem 
     The present invention constitutes the following structure to achieve such a purpose. 
     Specifically, the X-ray fluoroscopic imaging apparatus of the present invention comprises: an X-ray tube that irradiates an X-ray to a subject; an X-ray detector that is in place to face the X-ray tube and detects the X-ray transmitting the subject; a support mechanism that supports the X-ray tube and the X-ray detector while facing each other and is rotatable around the respective two axes that are orthogonal to each other; a rotation position detection element that detects information related to a rotation direction and a rotation angle around the respective axes of said support mechanism as a rotation position information; a plurality of memory switches; a rotation position memory storage element that stores said rotation position information in correspondence with any of said memory switches; a rotation position display element that displays said rotation position information that is stored in correspondence with such memory switches selected by selecting any of said memory switches; and a rotation instruction element that rotates the support mechanism in the rotation direction and with the rotation angle in correspondence with the rotation position information that are displayed on the rotation position information display element; wherein the rotation position memory element is configured to store a plurality of rotation position information in correspondence with the respective memory switches, and the rotation position information display element is configured to display in a predetermined display manner any of the plurality of rotation position information stored in correspondence with the memory switch by which the memory switch is operated in a predetermined manner. 
     In such a configuration, the rotation position information display element, a plurality of memory switches, the rotation position memory storage element and the rotation instruction element. The rotation position memory storage element stores the rotation position information of the support mechanism in correspondence with any of the memory switches and is configured to store a plurality of rotation position information corresponding to the respective memory switches. Specifically, every single memory switch is configured to be stored in correspondence with a plurality of rotation positions. Therefore, while cutting the number of the memory switches installed to the X-ray fluoroscopic imaging apparatus, a larger number of the rotation position information can be stored in correspondence with the memory switches. 
     The rotation position information display element displays the rotation position information that is stored in correspondence with such selected memory switches due to the selection of any of the memory switches. Further, the rotation position information display element is configured to display any of the plurality of rotation position information stored in correspondence with such memory switches in the predetermined manner due to operation of the memory switches in the predetermined manner. Specifically, the information of the respective rotation positions can be selectively read. out and displayed corresponding to the operation manner of the memory switch due to the configuration in which a plurality of the rotation positions is stored in correspondence with one memory switch. 
     And the support mechanism can be rotated in the rotation direction and with the rotation angle respectively corresponding to the rotation position information that is displayed on the rotation position information display element due to the operation of the rotation instruction element. Accordingly, an operation is now achievable, wherein the support mechanism is rotated to such a rotation position by selecting the one rotation position from a plurality of stored rotation positions with regard to the configuration in which the plurality of the rotation positions are stored in correspondence with one memory switch. 
     According to the present invention set forth above, it is preferable that the respective memory switches is in place in the position corresponding to the rotation direction stored in correspondence with the memory switch on the basis of the base (reference) region indicating the position of the subject. 
     [Action and Effect] With regard to the X-ray fluoroscopic imaging apparatus according to the present invention, the position, at which the respective memory switches are in place on the basis of the reference region, is defined so as to correspond to the direction of the rotation position stored in correspondence with the memory switches. 
     According to such a configuration, based on the position at which the memory switches are in place on the basis of the reference region, the operator can intuitively understand that the rotation position stored in correspondence with such memory switches is in any direction on the basis of the reference region. Therefore, the time needed for the auto-positioning operation can be reduced, and an incident of an error operation during the auto-positioning operation can be absolutely avoided. 
     The present invention may constitute the following structure to achieve such a purpose. 
     Specifically, the X-ray fluoroscopic imaging apparatus of the present invention comprises: an X-ray tube that irradiates an X-ray to a subject; an X-ray detector that is in place facing said X-ray tube detects said X-ray transmitting said subject; a support mechanism that supports said X-ray tube and said X-ray detector so as to face each other and is rotatable around respective two axes that are orthogonal to each other; a rotation position detection element that detects information of a rotation direction and a rotation angle around each axis of the support mechanism as a rotation position information; a rotation position memory storage element that stores a plurality of memory switches and the rotation position information in correspondence with any of the memory switches; a rotation position display element that displays the rotation position information that is stored in correspondence with the memory switch selected by selecting any of the memory switches; and a rotation instruction element that rotates the support mechanism in the rotation direction and with the rotation angle in correspondence with the rotation position information that is displayed on the rotation position information display element; a rotation position information erasing element that erases said rotation position information stored in correspondence with said respective memory switches due to an operation instructing a predetermined specific process of a series of examination processes relative to said subject as a trigger 
     [Action and Effect] The X-ray fluoroscopic imaging apparatus, according to the present invention, comprises the rotation position information display element, the plurality of memory switches, the rotation position memory storage element, the rotation instruction element and the rotation position information erasing element. The rotation position memory storage element stores the rotation position information of the support mechanism in correspondence with any of the memory switches. The rotation position information display element displays the rotation position information that is stored in correspondence with such memory switches selected by selecting any of memory switches. And the support mechanism is rotated in the rotation direction and with the rotation angle respectively corresponding to the rotation position information displayed on the rotation position information display element due to the operation of the rotation instruction element. According to the auto-positioning operation using such a configuration, the X-ray fluoroscopic imaging condition can be reproduced by re-shifting the support mechanism to such a rotation position during performing the procedural operation relative to the subject following storing the rotation position information of the support mechanism in correspondence with the memory switches. 
     And once the operation for instructing a specific predetermined process of a series of examination processes relative to the subject is performed, the rotation position information erasing element erases the rotation position information stored in correspondence with the respective memory switches due to such an operation as a trigger. According to such a configuration, once a series of examination processes relative to the subject is completed, the rotation position information stored in correspondence with the respective memory switches are automatically erased. In other words, the rotation position information stored in correspondence with the memory switches when the examination is conducted on the subject are stored only during the examination on such a subject. 
     In such a way, even when a number of rotation positions are needed to be stored since a number of subjects are examined, the information of the rotation positions is erased whenever the examination relative to the subject ends. Therefore, it is not required to forever and continuously store the rotation position information with regard to all subjects in correspondence with the respective individual memory switches. Specifically, the number of the memory switches is limited to the number of the rotation positions to be stored mandatory with regard to the examination relative to each subject. Therefore, while reducing the number of the memory switches installed to the X-ray fluoroscopic imaging apparatus, the examination for a number of subjects can be adequately performed using the auto-positioning operation. 
     In addition, according to the present invention set forth above, it is preferable that the rotation position memory storing element comprises the memory mode shifting instruction element that executes shifting to the memory mode to store the rotation position information in the memory switches and that the rotation position memory storing element stores the rotation direction and the rotation angle of the support mechanism at the time when the operation is executed in correspondence with the memory switches as the rotation position information by operating any of the memory switches in the shifting state at the memory mode. 
     [Action and Effect] According to the X-ray fluoroscopic imaging apparatus of the present invention, the rotation position memory storing element stores the rotation direction and the rotation angle of the support mechanism at the time when the operation is executed in correspondence with the memory switches as the rotation position information by operating any of the memory switches. Therefore, the information of such rotation position can be stored by operating the memory switches when it is found. that the support mechanism has rotated to the adequate rotation position to be stored. As a specific example, once it is found that the desired X-ray image is obtained by the X-ray fluoroscopic imaging, the rotation position information of the support mechanism at the time when the X-ray image is obtained is automatically stored by operating the memory switches. Specifically, the rotation position information corresponding to the X-ray image imaging condition is exactly and quickly stored, so that the rotation position required to obtain such an X-ray image can be easily and precisely reproduced later. 
     In addition, according to the present invention, a selected memory switch display mechanism is preferably included to display the latest memory switch operated by the operator among the plurality of memory switches in the different manner from other memory switches thereof. 
     [Action and Effect] According to the X-ray fluoroscopic imaging apparatus of the present invention, the selected memory switch display mechanism displays the latest memory switch operated by the operator in the different manner from other memory switches thereof. In such a configuration, the operator can absolutely identify the memory switch operated right before among the plurality of the memory switches, i.e., such a memory switch is a selection object for the auto-positioning operation at the present time. Therefore, an erroneous operation in the auto-positioning operation can be avoided, and the time needed for such an operation can be further shortened. 
     [Effects of the Present Invention] 
     According to the first aspect of the X-ray fluoroscopic imaging apparatus of the present invention, the rotation position memory storage element stores the rotation position information of the support mechanism in correspondence with any of the memory switches and is configured to store a plurality of rotation position information corresponding to the respective memory switches. Specifically, every single memory switch is configured to be stored in correspondence with the plurality of rotation positions. Consequently, while lowering the number of the memory switches installed to the X-ray fluoroscopic imaging apparatus, a larger number of the rotation position information can be stored in correspondence with the memory switches. 
     According to the second aspect, the rotation position memory storage element stores the rotation position information of the support mechanism in correspondence with any of the memory switches. And once the operation for instructing a specific predetermined process of a series of examination processes relative to the subject is performed, the rotation position information erasing element erases the rotation position information stored in correspondence with the respective memory switches using such an operation as a trigger. Therefore, even when a number of rotation positions are needed to be stored since a number of subjects are examined, the information of the rotation positions is erased whenever the examination relative to the subject ends. Therefore, it is not required to forever and continuously store the rotation position information with regard to all subjects in correspondence with the respective individual memory switches. Therefore, while lowering the number of the memory switches installed to the X-ray fluoroscopic imaging apparatus, the auto-positioning can be performed on a larger number of rotation positions for many subjects. 
     The above and other aspects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view illustrating the entire structure of an X-ray fluoroscopic imaging apparatus according to the Embodiment. 
         FIG. 2  is a right-side view illustrating the entire structure of the X-ray fluoroscopic imaging apparatus according to the Embodiment 
         FIG. 3  is a schematic functional block diagram illustrating the X-ray fluoroscopic imaging apparatus according to the Embodiment. 
         FIG. 4  is a schematic diagram illustrating the rotation direction of the C-arm according to the Embodiment. 
         FIG. 5  is a perspective view illustrating an input element according to the Embodiment. 
         FIG. 6  is a view illustrating a display screen in the default mode of the touch panel according to the Embodiment. 
         FIG. 7  is the functional block diagram illustrating the essential components of the X-ray fluoroscopic imaging apparatus according to the Embodiment. 
         FIG. 8  is a list table illustrating the correspondence between the memory switches and memories and the rotation position information registered in advance in the memory. 
         FIG. 9A, 9B, 9C  are flow charts illustrating a variety of operation steps of the X-ray fluoroscopic imaging apparatus according to the aspect of the Embodiment. 
         FIG. 9A  is a flow chart illustrating the auto-positioning operation in the default mode. 
         FIG. 9B  is a flow chart illustrating the operation to register the rotation position information into the first memory switch group in the registration mode 
         FIG. 9C  is a flow chart illustrating the operation to register the rotation position information in the second memory switch group in the edition mode. 
         FIG. 10  is a view illustrating a touch panel display screen at Step S 3  according to the Embodiment. 
         FIG. 11  is a schematic diagram illustrating the essential component of the X-ray fluoroscopic imaging apparatus at Step S 3  according to the aspect of the Embodiment. 
         FIG. 12  is a view illustrating a touch panel display screen at Step P 1  according to the Embodiment. 
         FIG. 13  is a schematic diagram illustrating the essential component of the X-ray fluoroscopic imaging apparatus at Step P 2  according to the aspect of the Embodiment. 
         FIG. 14  is a view illustrating a touch panel display screen at Step P 2  according to the Embodiment. 
         FIG. 15  is a view illustrating a touch panel display screen at Step P 5  according to the Embodiment. 
         FIG. 16  is a functional block diagram illustrating the essential component of the X-ray fluoroscopic imaging apparatus at Step P 5  according to the Embodiment. 
         FIG. 17  is a view illustrating a touch panel at Step P 4  when the manual selection mode is selected according to the Embodiment 
         FIG. 18  is a view illustrating a touch panel display screen at Step T 1  according to the Embodiment. 
         FIG. 19  is a schematic diagram illustrating the essential component of the X-ray fluoroscopic imaging apparatus at Step T 3  according to the aspect of the Embodiment. 
         FIG. 20  is a view illustrating a touch panel display screen at Step T 3  according to the Embodiment. 
         FIG. 21  is a functional block diagram illustrating the control mechanism of the information erase element according to the Embodiment. 
         FIG. 22  is a plane view illustrating a structure of a console according to a conventional example. 
         FIG. 23  is a plane view illustrating the problem of the operation panel of the conventional Embodiment. 
         FIG. 24  is a plane view illustrating a structure of the console according to the alternative Embodiment. 
         FIG. 25  is a plane view illustrating Step S 3  according to the alternative Embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to embodiments of the invention. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. The word ‘couple’ and similar terms do not necessarily denote direct and immediate connections, but also include connections through intermediate elements or devices. For purposes of convenience and clarity only, directional (up/down, etc.) or motional (forward/back, etc.) terms may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope in any manner. It will also be understood that other embodiments may be utilized without departing from the scope of the present invention, and that the detailed description is not to be taken in a limiting sense, and that elements may be differently positioned, or otherwise noted as in the appended claims without requirements of the written description being required thereto. 
     Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments of the present invention; however, the order of description should not be construed to imply that these operations are order dependent. 
     Referring to Figures, the inventor sets forth Embodiments of the present invention. 
     (Illustration of the Entire Structure) 
     Referring to  FIG. 1  and  FIG. 2 , the X-ray fluoroscopic imaging apparatus  1  according to the Embodiment comprises an X-ray tube  5  and an X-ray detector  7  which are facing each other while sandwiching the subject M on the table  3  in a supine posture. The X-ray tube  5  irradiates the X-rays to the subject M. The X-ray detector  7  detects and converts the X-ray, which is irradiated from the X-ray tube  5  to the subject M and transmits therethrough, to an electric signal and then outputs the electric signal as an X-ray detection signal. One example of the X-ray detector  7  is such as a flat panel detector (FPD). 
     The X-ray tube  5  and the X-ray detector  7  are respectively installed to a C-arm  9 . The C-arm  9  has an approximately C-like bending shape. The X-ray tube  5  is installed to one end of the C-arm  9  and the X-ray detector  7  is installed to the other end of the C-arm  9 . The C-arm  9  that is held by the arm holding member  11  capable of sliding along the circular arc pathway of the C-arm  9  indicated by the sign RA. The C-arm  9  slides in the direction denoted by the sign RA, i.e., rotates around the axis orthogonal to the body axis (hereinafter body axis direction) of the subject M. 
     The arm holding member  11  that is installed to the side portion of the supporting column  13  is configured to be rotatable around the horizontal axis RB parallel to the x-direction (long side of the fluoroscopy range during the table 3 and also called around the body axis) and body axis direction). The C-arm  9  that is held by the arm holding member  11  rotates around the body axis of the subject M in accordance with rotation of the arm holding member  11 . 
     According to the present Embodiment as set forth above, the C-arm  9  rotates independently around two axes orthogonal to each other (e.g., the body axis direction of the subject M and the circumference direction of the body axis). In addition, the direction consisting of the body axis direction of the subject M and the circumference direction of the body axis thereof is called collectively hereinafter “rotation direction”. The C-arm  9  rotates freely and respectively around the orthogonal two axes to each other along the respective arch path RA and arch path RB, so that X-rays can be irradiated to the subject M from arbitrary directions. The C-arm  9  corresponds to the support mechanism of the present invention. 
     In addition, referring to  FIG. 1  and  FIG. 2 , the state in which the X-ray tube  5  and the X-ray detector  7  are perpendicular relative to the subject M is the initial (default) state of the C-arm  9 . And the rotation position of the C-arm  9  in the initial sate is defined as the default position of the C-arm  9 . With regard to the default position of the C-arm  9 , the rotation angle of the C-arm is specified as 0° for the respective body axis direction and circumference direction of body axis. 
     The support column  13  that is supported by the support pedestal base  15  installed to the floor surface is movable horizontally in the v-direction (short side direction of the table 3). The arm holding member  11  and the C-arm  9  supported by the support column  13  move in the y-direction following the horizontal move of the support column  13 . The collimator  17  installed below the X-ray tube  5  limits X-rays irradiated from the X-ray tube  5  to a predetermined shape. An example of the limited shape of the X-ray may be a cone shape like a pyramid. 
     Next, the inventors set forth the rotation mechanism of the C-arm  9 . The rotation of the C-arm  9  in the body axis direction of the subject M is achieved using a driving mechanism inside the arm holding member  11 . A part of a belt  19  of which both ends are fixed to the C-ram  9  is housed inside the arm holding member  11 , and the belt  19  is bridged with a driving roller  23  through a guide roller  21 . 
     A driving motor M 1  and a rotary encoder R 1  are attached inside the arm holding member  11 . The driving motor M 1  rotates the driving roller  23 . The rotary encoder R 1  detects the rotation direction and rotation of the driving motor M 1 . The C-arm  9  rotates
         in the body axis direction of the subject M through the belt  19  due to the rotation of the rotation motor M 1 . In addition, for convenience of explanation, referring to  FIG. 1 , the driving motor M 1  and the rotary encoder R 1  are shown outside the arm holding member  11 .       

     The rotation of the C-arm  9  in the circumference direction of the body axis of the subject M is achieved by rotating the arm holding member  11  in the circumference direction of the horizontal axis RB, i.e., the circumference direction of the body axis of the subject M. The pedestal base portion of the arm holding member  11 , i.e., the opposite end of the side holding the C-arm  9 , is supported with the side portion of the support column  13  so as to be rotatable and a gear  25  is fixed near the support plane. 
     The gear  25  is occluded with a pinion gear  27 , and the pinion gear  27  is mounted on the output shaft of the driving motor M 2  installed inside the support column  13 . The C-arm  9  rotates in the circumference direction of the body axis of the subject M together with the arm holding member  11  due to rotation of the driving motor M 2 . The rotary encoder R 2  detects the rotation direction and rotation of the driving motor M 2 . 
     Referring to  FIG. 3 , the X-ray fluoroscopic imaging apparatus  1  further comprises an X-ray irradiation control element  29 , an image generation element  30 , an image display element  31 , a motor control element MD 1 , a motor control element MD 2 , a rotation position detection element  33 , a main control element  35 , a memory storage element  37  and a console  39 . The X-ray irradiation control element  29  is configured to output a high voltage to the X-ray tube  5 . And the dose of X-ray irradiated by the X-ray tube  5  and the timing of X-ray irradiation are controlled based on the high voltage output provided by the X-ray irradiation control element  29 . 
     The image generation element  30  that is installed to the latter part of the X-ray detector  7  generates an X-ray image based on the X-ray detection signal output from the X-ray detector  7 . The image display element  31  that is installed to the latter part of the image generation element  30  displays the X-ray images generated by the image generation element  30 . An example of the image display element  31  is a liquid crystal monitor. As a structural example, the image display element  31  is hanging from ceiling or loaded on a movable wheeled platform. 
     The motor control element MD 1  is installed in the upstream of the driving motor M 1  and controls the rotation direction and rotation of the driving motor M 1 . The motor control element MD 2  is installed in the upstream of the driving motor M 2  and controls the rotation direction and rotation of the driving motor M 2 . 
     The rotation position detection element  33  detects the rotation position of the C-arm  9  based on the rotation direction and rotation of the driving motor M 1  detected by the rotary encoder R 1  and the rotation direction and rotation of the driving motor M 2  detected by the rotary encoder R 2 . The rotation position of the C-arm  9  is identified according to the rotation direction and rotation of the C-arm  9 . 
     The rotation direction of the C-arm  9  is expressed as follows. Referring to  FIG. 4 , with regard to the body axis direction of the subject M, the head side direction thereof is denoted in CRA (cranial) hereinafter and the foot side direction thereof is denoted in CAU (caudal) hereinafter. And referring to FIG. axis of the subject M, the rotation direction to the left side from the head side direction thereof is denoted in LAO (left anterior oblique) hereinafter and the rotation direction to the right side from the head side thereof is denoted in RAO (right anterior oblique) hereinafter. 
     The rotation direction of the C-arm  9  is specified by a combination of the rotation direction (CRA or CAU) of the C-arm  9  in the body axis directions of the subject M and the rotation direction (LAO or RAO) of the C-arm  9  in the circumference direction of the subject M. And the rotation angle of the C-arm  9  is specified by a combination of the rotation angle of the C-arm  9  in the body axis directions of the subject M and the rotation angle of the C-arm  9  in the circumference direction of the body axis of the subject M. 
     A rotation position detection element  33  calculates the rotation direction and rotation angle of the C-arm  9  which rotates in the body axis direction of the subject M based on the information of the rotation direction and rotation of the driving motor M 1 , which the rotary encoder R 1  sends. And the rotation position detection element  33  detects the rotation direction and rotation angle of the C-arm  9  which rotates in the circumference direction of the body axis of the subject M based on the information of the rotation direction and rotation of the driving motor M 2 , which the rotary encoder R 2  sends. And the rotation direction and rotation angle of the C-arm  9  are calculated based on such information. 
     A main control element  35  comprises an information processing means, such as a central processing unit (CPU) as an example. The main control element  35  controls comprehensively a variety of components of the X-ray fluoroscopic imaging apparatus  1 , e.g., the motor control element MD 1 , the motor control element MD 2 , the X-ray irradiation control element  29 , the image generation element  30  and the image display element  31 . 
     The memory storage element  37  stores a variety of information, e.g., the information as to the X-ray imaging condition including such as the tube voltage and the tube electric current, a variety of X-ray images generated by the image generation element  30  and the information related to the image processing with the image generation element  30  and the rotation position information of the C-arm  9 . 
     A console  39  is used to input the operator&#39;s instruction relative to the operation of the X-ray fluoroscopic imaging apparatus  1 , and the main control element  35  conducts a comprehensive control following the instruction which the operator inputs using the console  39 . Examples of the console  39  includes e.g., a key-board panel, a touch input panel, a mouse, a dial, a change switch and a push button switch. 
     According to the present Embodiment, referring to  FIG. 1 , the console  39  is attached to the side portion of the table 3. In such a case, the operator stands near by the table 3 and operates the console  39  while standing. The console  39  is attached to the table 3, so that the operator can perform a variety of operations as for the X-ray fluoroscopic imaging apparatus  1  while performing a catheter procedure or an examination for the subject M. 
     In addition, the console  39  is not limited to be attached to the side portion of the table 3, and the top plane of the removable wheeled platform may be equipped with the console  39 . In addition, the console  39  is not limited to be in place in the long side portion of the table 3, and the console  39  may be attached to the short side portion of the table 3. 
     Next, the inventors set forth essential operation devices installed to the console  39 . Referring to  FIG. 5 , the console  39  comprises the arm operation lever  41 , the touch panel  43 , the rotation instruction switch  45  and the end instruction switch  47 . 
     The arm operation lever  41  is configured to be tiltable back and forth and around and adjusts the rotation position of the C-arm  9 . For example, provided the operator grips the arm operation lever  41  and tilts forth, the C-arm  9  rotates in the LAO direction. The rotation angle of the C-arm  9  changes corresponding to the tilt angle of the arm operation lever  41  or the time period of tilting. Further, provided the operator grips the arm operation lever  41  and tilts to the left direction, so that the C-arm  9  rotates in the CRA direction. The operator can manually and finely adjust the rotation position of the C-arm  9  using the arm operation lever  41 . 
     The touch panel  43  runs a such as an operation for storing the rotation position of the C-arm  9  and displays a number of iconic switches. In addition, a plurality of the modes such as an default mode, a registration mode and an edition mode is arbitrarily switched, so that the displayed iconic switch is changed accordingly. The inventors set forth later the structure of the touch panel  43  and a variety of modes. The touch panel  43  corresponds to the rotation position information display element in the present invention. 
     A rotation instruction switch  45  is a push button switch for moving the C-arm  9  to the predetermined rotation position. Specifically, the C-arm  9  rotates toward such a specific rotation position by pushing down the rotation instruction switch  45  in the state in which the stored specific rotation position is selected using the touch panel  43 . The rotation instruction switch  45  corresponds to the rotation instruction element of the present invention. 
     The end instruction switch  47  is a push button switch and operated when ending the preset procedural operation for the subject M. The X-ray fluoroscopic imaging becomes operable as to the next procedural operation and the end of the action once the operator pushes down the end instruction switch  47 . In addition, according to the present Embodiment, the information of the rotation positions stored in correspondence with the respective memory switches  57  constituting the second memory switch group M 2  is erased once the operator pushes down the end instruction switch  47 . 
     In addition, the inventors set forth while limiting the four operation devices related to adjustment of the rotation position of the C-arm  9 , but the device installed to the console  39  is not limited to such four devices. Specifically, an operation device as to the operation of the X-ray fluoroscopic imaging apparatus  1  such as a switch to turn on and off the main electric power, a switch to set up the imaging conditions, a switch to adjust the position of the table 3, or an emergency shutdown switch to stop can be arbitrary installed. 
     Next, the inventors set forth the structure of the touch panel  43  in detail.  FIG. 6  is a view illustrating the touch panel  43  in the default mode. The default mode is the mode of the touch panel  43  in the default (initial) state and the mode by which the auto-positioning operation to automatically rotate the C-arm  9  to the predetermined rotation position is executed. 
     &lt;Structure of the Default Mode&gt; 
     The touch panel  43  comprises a first memory switch group M 1 , a second memory switch group M 2 , a registration shifting switch  49 , and an edition shifting switch  51 . According to the present Embodiment, the respective switches are icons displayed on the touch panel  43 . 
     The first memory switch group M 1  comprises the center switch  53  and a plurality of memory switches  55 . The center switch  53  is in place in the center of the first memory switch group M 1  and displayed as a human shape symbol illustrating the subject M in the supine position. The respective memory switches  55  are in place around the center switch  53 . According to the present Embodiment, referring to  FIG. 6 , it is given that the first memory switch group M 1  comprises the eight memory switches  55   a - 55   h.  The number of the memory switches  55  is not limited eight and may he arbitrarily changed. 
     With regard to the first memory switch group M 1 , the respective memory switches are in correspondence with the information of a plurality of the rotation positions. According to the present Embodiment, the respective memory switches  55  are in correspondence with three kinds of the rotation position information. Specifically, referring to  FIG. 7 , the memory storage element  37  comprises a rotation position memory storage element  61 . The rotation position memory storing element  61  stored the predetermined rotation position information in correspondence with the memory switches  55 . 
     The rotation position memory storage element  61  comprises a plurality of the first memory  63 , the second memory  64  and the third memory  65  in correspondence with the respective memory switches  55 . Hereinafter, when the first memory  63 , the second memory  64  and the third memory  65  are collectively called, it calls the memories  63 - 65 . The respective memories  63 - 65  may store one kind of the rotation position information of the C-arm  9 . 
     Specifically, referring to  FIG. 7 , the respective memory switches  55  are in correspondence with total three memories  63 - 65 . Therefore, the rotation position memory storing element  61  enables storing the respective memory switches  55  in correspondence with the three kinds of the rotation position information. 
     In addition, referring to  FIG. 8 , the memories  63 - 65  corresponding to the memory switches  55   a  have the sign a to make the memories  63   a - 65   a  to be distinguishable from other memories  63 - 65 . Also, the memories  63 - 65  corresponding to the memory switches  55   n  have the sign n to be distinguishable from other memories  63 - 65 . 
     The information of the rotation positions relative to the respective memory switches  55   a - 55   h  stored in advance in correspondence therewith is illustrated as shown in  FIG. 8 . Specifically, the memory switches  55   a  are stored in correspondence with the rotation position at which the C-arm  9  rotates in the CRA direction and the LAO direction from the default position shown in  FIG. 1 . 
     First, the information of the rotation position (rotation position information F 1 ) at which the C-arm  9  rotates 30° in the LAO direction from the default position and then 30° in the CRA direction therefrom is preliminarily (in advance) stored in correspondence with the first memory  63   a.  The rotation position at which the C-arm  9  rotates 20° in the LAO direction from the default position and then 40° in the CRA direction therefrom is stored as the rotation position F 2  in correspondence with the second memory  64   a  therein. The rotation position at which the C-arm  9  rotates 50° in the LAO direction from the default position and then 10° in the CRA direction therefrom is stored as the rotation position F 3  in correspondence with the third memory  64   a  therein. 
     The information of the rotation positions F 4 -F 6  as the information in correspondence with the memory switch  55   b  is stored respectively in the first memory  63  through the third memory  63   b.  The rotation positions F 4 -F 6  are the positions following rotation of the C-arm  9  from the default position in the LAO direction. The information of the rotation positions F 7 -F 9  as the information in correspondence with the memory switch  55   c  is stored respectively in the first memory  63   c  through the third memory  65   c.  The rotation position is where the C-arm  9  has rotated from the default position in the LAO direction and in the CAU direction. 
     Also, the information of the rotation positions F 10 -F 21  is preliminarily stored as the information in correspondence with the memory switches  55   d - 55   h.  In addition, referring to  FIG. 8 , it is given that the rotation position information is not registered in the third memory  65   g  corresponding to the memory switch  55   g  and also the second memory  64   h  and the third memory  65   h  corresponding to the memory switch  55   h  respectively. 
     In addition, the rotation position memory storing element  61  further comprises the memory  66 . The memory  66  is in correspondence with the center switch  53 , and the information of the default position of the C-arm  9  is preliminarily stored as the rotation position F 0  in the memory  66 . Specifically, the center switch  53  is used when the C-arm  9  returns to the default position. 
     The position at which the respective memory switches  55  are in place on the basis of the center switch  53  is defined in accordance with the rotation position stored in correspondence with the memory switches  55 . For example, the rotation position at which the C-arm  9  rotates from the default position in the CRA direction and in the LAO direction is stored in the memory switches  55   a  in correspondence therewith. 
     Referring to  FIG. 4 , the CRA direction is the left-side direction, and the LAO direction is the right-side direction on the basis of the position of the subject M. Therefore, the memory switch  55   a  in which the rotation position information in the CRA direction and in the LAO direction is in place upper left side on the basis of the center switch  53 . Also, with regard to the memory switches  55   b - 55   h,  the position at which the memory switches  55   b - 55   h  are in place is decided corresponding to the direction of the rotation position stored in correspondence therewith. The position at which the center switch  53  is in place is the reference region of the present invention. 
     The second memory switch group M 2  comprises a plurality of memory switches  57 . According to the present Embodiment, referring to  FIG. 6 , it is given that the second memory switch group M 2  comprises the three memory switches  57   a - 57   c.  The number of the memory switches  57  is not limited to three and may be arbitrarily changed. The first memory switch group M 1  is used when the information of the rotation positions of the C-arm  9  is stored for a long time and on the other hand, the second memory switch group M 2  is used when the information of the rotation positions of the C-arm  9  is stored temporarily. 
     Accordingly, the respective memory switches  57  are in correspondence with each one kind of the rotation position information. Specifically, the rotation position memory storing element  61  further comprises the same number of the short-term memories  67  as the number of the memory switches  57 . According to the present Embodiment, the number of the memory switches  57  are three referring to  FIG. 7 , so that the rotation position memory storing element  61  comprises the three short-term memories  67   a - 67   c.  The short-term memory  67   a  is in correspondence with the memory switch  57   a,  and the short-term memory  67   b  is in correspondence with the memory switch  57   b.  The short-term memory  67   c  is in correspondence with the memory switch  57   c.    
     Referring to  FIG. 6  and  FIG. 8 , the rotation position at which the C-arm  9  rotates 40° from the default position in the LAO direction and also 30° in the CAU direction therefrom is preliminarily stored in the short-term memory  67   a  as the rotation position F 22 . It is given that the rotation position information is not registered yet in the short-term memory  67   b  and in the short-term memory  67   c.    
     The registration shifting switch  49  is applied to input the instruction to shift the screen, which is displayed on the touch panel  43 , from the default mode to the registration mode. Once the operator pushes down the registration shifting switch  49 , the display screen of the touch panel  43  shifts from the default mode for performing the auto-positioning to the registration mode. The operation to instruct the first memory switch group M 1  to store in correspondence with the predetermined rotation becomes workable by shifting to the registration mode. 
     The edition shifting switch  51  is applied to input the instruction to shift the screen, which is displayed on the touch panel  43 , from the default mode to the edition mode. Once the operator pushes down the edition shifting switch  51 , the display screen of the touch panel  43  shifts from the default mode for performing the auto-positioning to the edition mode. The operation to instruct the second memory switch group M 2  to store in correspondence with the predetermined rotation position information can be available by shifting to the edition mode. The registration mode or the edition mode corresponds to the memory storing mode of the present invention. The registration shifting switch  49  or the edition shifting switch  51  corresponds to the memory storing shifting instruction element of the present invention. 
     Referring to  FIG. 7 , the main control element  35  further comprises a read-out element  69 , a display control element  71 , a memory storing control element  73  and a position information erasing element  75 . The read-out element  69  selects and reads out the information of the rotation position stored in the memories  63 - 66  or the short-term memory  67  corresponding to the operation relative to such as the edition shifting switch  51  and the memory switches  55 . 
     The display control element  71  displays the information of the rotation position that the read-out element  69  reads out, and the additional information as to such a read-out rotation position information on the touch panel  43 . As an example of the additional information, such as the information of identifying the memory in which the read-out rotation position information is stored and the information of identifying whether the rotation position information stored in the memories  63 - 65  exists or not may be listed. The display control element  71  corresponds to the selection memory switch display mechanism of the present invention. 
     The memory control element  73  stores the rotation position information of the C-arm  9  in the rotation position memory storage element  61  due to the operation of the registration instruction switch  83  as a trigger later set forth. The position information erasing element  75  erases the rotation position information stored in correspondence with the respective memory switches  57  due to the predetermined operation relative to the X-ray fluoroscopic imaging apparatus  1  as a trigger. According to the present Embodiment, the push-down operation of the end instruction switch  51  is applied to the trigger for erasing the rotation position information. The position information erasing element  75  corresponds to the rotation position information erasing element of the present invention. 
     &lt;Auto-Positioning Operation&gt; 
     Next, the inventor sets forth the action for the auto-positioning using the X-ray fluoroscopic imaging apparatus according to the present invention.  FIG. 9A  is the flow chart illustrating an auto-positioning operation. Here, the inventors set forth the case in which the C-arm  9  rotates automatically to the rotation position F 8  that is the rotation position following the rotation 45° in the LAO direction from the default position and 20° in the CAU direction therefrom. 
     First, the operator set up the touch panel  43  of the console  39  to the default mode by executing the start-up thereof. Referring to  FIG. 6 , once the touch panel  43  shifts to the default mode, the display control element  71  displays the page (screen) for the auto-positioning on the touch panel  43 . 
     Next, the operator selects the memory switches  55  or the memory switches  57  in correspondence with the information of the rotation position that is the target. When the memory switches  55  in correspondence with a plurality of the rotation position information is selected, the operator intuitively enables the proper selection of the memory switches  55  based on the position at which the memory switches  55   a - 55   h  are in place. As an example, when the C-arm  9  rotates from the default position in the LAO direction and in the CAU direction, the LAO direction is the upper side and the CAU direction is the right side from the reference that is a humanoid symbol displayed in the center switch  53 . Specifically, for rotating in the LAO direction and the CAO direction, the operator can intuitively decide that it is adequate to select the memory switch  55   c  that is in place upper right side from the center switch as the reference. 
     In addition, the respective memory switches  57  are in correspondence with each one kind of the rotation position information, so that the display control element  71  can display such rotation position information on the touch panel in the default mode. Specifically, referring to  FIG. 6 , the information of the rotation position F 22  in correspondence with the memory switch  57   a  and registered thereof is displayed. Accordingly, when the auto-positioning is executed using the rotation position information in correspondence with the memory switch  57 , the operator can determine if the memory switch  57  in correspondence with the target rotation position exists or does not while watching the screen of the touch panel  43  in the default mode. Here, referring to  FIG. 6 , it can be determined by visually recognizing the display of the second memory switch group M 2  that the respective memory switches  57   a - 57   c  are not in correspondence with the information of the rotation position F 8 . Therefore, the operator selects the memory switch  55   c  but not the memory switch  57 . 
     When selecting the memory switches  55 , the operator can read out the target rotation position information from the memories  63 - 65  by operating the selected memory switches  55  in the respectively different manners (Step S 3 ). According to the present Embodiment, the memories  63 - 65  that are read-out targets are distinguished due to the number of pushing-downs of the memory switches  55 . 
     Specifically, the read-out element  69  reads out the rotation position information stored in the first memory  63  by operating the memory switches  55  in the manner (first manner) in which the memory switches  55  is pushed down once by the operator. The read-out element  69  reads out the rotation position information stored in the second memory  64  by the operation (second manner) in which the memory switches  55  are pushed down twice. The read-out element  69  reads out the rotation position information stored in the third memory  65  by operation (third manner) in which the memory switches  55  are pushed down three times. In addition, when the memory switches  55  are pushed down four times, the target read out by the read-out element  69  returns to be the first memory  63  and further, every time when the memory switch  55  is pushed down, the memory that is the target to be read out is changed. 
     Referring to  FIG. 8 , the information of the rotation position F 8  is stored in the second memory  64   c  in correspondence with the memory switch  55   c.  Therefore, the operator enable the selection of the information of the rotation position E 8  by pushing down the memory switch  55   c  twice. Once the operation of pushing down the memory switch  55   c  twice is executed as the trigger, the read-out element  69  determines that the read-out target is the second memory  64   c.  And referring to  FIG. 11 , the rotation position information is read out from the second memory  64   c  and the information of such the information of such a rotation position F 8  is sent out to the display control element  71 . 
     The display control element  71  displays the read-out rotation position information F 8  on the touch panel  43 . At this time, the display control element  71  displays not only the information of the rotation position F 8  but also the information (additional information Sp) denoting that the latest operated memory switch is the memory switch  55   c  of the memory switches  55  and the information (additional information Qt) denoting that the target for the read-out processing done by the read-out element  69  is the second memory  64  between the first memory  63  and the third memory  65  on the touch panel  43 . The display screen of the touch panel  43  changes from the state referring to  FIG. 6  to the state referring to  FIG. 10  due to the control that the display control element  71  executes. In addition, according to the present invention, the latest operated memory switches  55  means the memory switches  55  is subject to the latest operation selected as the target for the auto-positioning operation, i.e., the memory switches  55  that is the selection target for the auto-positioning operation at the present time. 
     As the example of the additional information Sp, the selected memory switches  55  turns a light on, blink the light and change the color and so forth. Referring to  FIG. 10 , according to the present Embodiment, the memory switches  55  selected at the present time is provided with a thick line frame which indicates that is the additional information Sp. The additional information Sp is displayed on the touch panel  43 , so that the operator can intuitively understand that the memory switch  55   c  is selected from the first memory switch group M 1 . 
     According to the present Embodiment, the additional information Qt includes two kinds of information that is the information identifying the number of the rotation positions registered in the memory switches  55  and the information identifying the memories  63 - 65  that are the current read-out targets. Referring to  FIG. 10 , the additional information Qt are represented by the three circular symbols arrayed in series from right to left. The number of the circular symbols denotes the number of the rotation positions registered in such memory switches  55 . The additional information Qt added to the memory switches  55  has three symbols. Consequently, the operator can confirm by visually recognizing the additional information Qt that the number of the rotation position information already registered in the memory switches  55  at the present time is three. 
     In addition, the location of the black circular symbol in the series of the three circular symbols forming the additional information Qt identifies which one is the current read-out target among the memories  63 - 65 . For an example, provided the read-out target is the first memory  63 , the additional information Qt appears as ●∘∘. Specifically, the left end symbol is displayed as the black circle and the rest of two symbols are displayed as the white circle. Provide the read-out target is the second memory  64 , the additional information Qt appears as ∘●∘. Specifically, the second symbol from left is displayed as the black circle. Provided the read-out target is the second memory  64 , the additional information Qt appears as ∘∘●. Specifically, the third symbol from left is displayed as the black circle. 
     When the read-out and displayed rotation position in the memory switches  55  coincides with the rotation position of the C-arm  9  at the present time, the display control element  71  displays the additional information in the memory switches  55 . The additional information is displayed in the different manner from the additional information Sp and a whole or a part of the memory switches  55  that are the current selection targets may be blinked or subject to change the color thereof. The operator can confirm by visually recognizing the additional information that the C-arm  9  has reached to the rotation position displayed in the selected target memory switches  55 . According to the present Embodiment, the additional information is deemed displayed by blinking and displaying the whole of the memory switches  55  selected at the present time. 
     The operator visually recognizes the rotation position information and the additional information Qt displayed in the memory switches  55  every time when the memory switches  55  are pushed down. The operator identifies the read-out target memories  63 - 65  and confirms the contents of the read-out rotation position information by visually recognizing the rotation position information and the additional information Qt. 
     Referring to  FIG. 10 , the additional information Qt appeared as ∘●∘ is displayed in the memory switches  55  by executing the operation in which the memory switch  55   c  is pushed down twice. Therefore, the operator can intuitively understand by visually recognizing such an additional information Qt that the information of the rotation position information F 8  is read out in the second memory  64   c  among the first memory  63   c,  the second memory  64   c  and the third memory  65   c.    
     The operator pushes down the rotation instruction switch  49  to rotate the C-arm to the target position following confirming that the read-out and displayed rotation position information in the touch panel  43  is the information of the target rotation position F 8  (Step S 4 ). Specifically, once pushing down the rotation instruction switch  49  in the state in which the information of the rotation position F 8 , the additional information Sp and the additional information Qt are displayed in the memory switches  55 , the C-arm  9  is subject to an action to rotate to the rotation position F 8  while pushing down the rotation instruction switch  49 . The C-arm  9  rotates and once reached to the rotation position F 8  that is the target rotation position, the additional information indicating that the current position of the C-arm  9  coincides with the rotation position F 8  are displayed in the memory switches  55 . The operator visually recognizes such an additional information and confirms that the C-arm  9  has rotated to the target rotation position F 8  thereby. The operator performs the X-ray fluoroscopy or the X-ray imaging by irradiating the X-ray to the subject M from the X-ray tube  5  following confirming that the C-arm  9  has rotated to the target rotation position. 
     &lt;Structure of the Registration Mode&gt; 
     In addition, according to the present Embodiment, the number of the circular symbols forming the additional information Qt is three. Consequently, when the information of the target rotation position is not displayed on the touch panel  43  even though the operator pushes down the memory switches  55  three times, the operator can understand easily and quickly that no target rotation position information is stored in memory switches  55 . 
     As an example, in the case of using the registration mode, the case in which the information of the target rotation position is not stored in none of the memory switches  55  may be listed. In such a case, the operator shifts the touch panel  43  to the registration mode and executes the operation to store the new target rotation position. Here, the inventors set forth the configuration in which the new rotation position information in correspondence with the memory switches  55  is applied to overwrite and stored in the registration mode. 
     When overwritten with the new rotation position information in correspondence with the memory switches  55 , first the registration shifting switch  49  is pushed down to shift the touch panel  43  from the default mode to the registration mode. The display control element  71  changes the display screen of the touch panel  43  from the state referring to  FIG. 6  to the state referring to  FIG. 12  due to shifting to the registration mode. 
     Referring to  FIG. 12 , the touch panel  43  that shifts to the registration mode comprises a first memory switch group M 1 , a memory selection switch  77 , a current position display element  79 , a registration setting selection switch  81 , a registration instruction switch  83  and a mode return switch  85 . The display control element  71  shifts to the registration mode and thereby displays the additional information St that indicates if the stored rotation position information exists or not as to the respective memory switches  55  in correspondence with a plurality of the memories  63 - 65  of the first memory switch group M 1 . 
     The additional information St is represented by the three circular symbols arrayed in series from right to left as well as the additional information Qt. The left end symbol indicates if the rotation position information exists or not in the first memory  63 . The center symbol indicates if the rotation position information exists or not in the second memory  64 . The right end symbol indicates if the rotation position information exists or not in the second memory  65 . When the symbol is the black circle, it is indicated that the rotation position information is already registered in the memories  63 - 65  corresponding to such a symbol. When the symbol is the white circle, it is indicated that no rotation position information is yet registered in the memories  63 - 65  corresponding to such a symbol. 
     As an example, referring to  FIG. 8 , the rotation position information is already registered respectively in every memory from the first memory  63  through the third memory  65  respectively in correspondence with the memory switches  55   a - 55   f.  Consequently, all three kinds of additional information St displayed in the memory switches  55   a - 55   f  are indicated by the black circular symbols (●●●). With regard to the memory switch  55   g,  the rotation position information is not yet registered only in the third memory  65   g.  Consequently, the additional information St displayed in the memory switch  55   g  is indicated by having the three circular symbols (●●∘) having the white circle at the right end location. With regard to the memory switch  55   h,  the rotation position information is registered only in the first memory  65   h.  Consequently, the additional information St displayed in the memory switch  55   h  is indicated by having the three circular symbols (●∘∘) having the black circle only at the left end location. 
     The operator visually recognizes the additional information St and thereby can intuitively and comprehensively understand if the stored rotation position information exists or not as to the respective memories  63 - 65  corresponding to the memory switches  55   a - 55   h.    
     The memory selection switches  77  selects the memories  63 - 65  that are the targets in which the rotation position information is newly stored. The memory selection switches  77  comprises the memory selection switch  77   a  corresponding to the first memory  63 , the memory selection switch  77   b  corresponding to the second memory  64  and the memory selection switch  77   c  corresponding to the third memory  65 . The number of the memory selection switches  77  is determined corresponding to the number of rotation position information that is stored in accordance with the memory switches  55 . 
     The current position information display element  79  displays the information of the rotation position of the C-arm  9  at the present time that the rotation position detection element  33  detects. The registration setting selection switch  81  comprises a first switch  81   a  that shifts the information of the rotation position of the C-arm  9  at the present time to the state to be registered (direct registration mode) and the second switch  81   b  that shifts the information of the rotation position that the operator sets arbitrary to the state to be registered (manual registration mode). The state of the registration mode in the initial state is the state in which the first switch  81   a  selects the direction registration mode. 
     &lt;Operation of the Registration Mode&gt; 
     Here, the inventors set forth the operation to register the new rotation position information with the memory switches  55  in the registration mode.  FIG. 9B  is the flow chart illustrating the operation to register the new rotation position information in the memory switches  55 . Here, the inventors set forth the case in which the information of the rotation position FA that is the current position of the C-arm  9  is newly registered relative to the third memory  65   a  corresponding to the memory switch  55   a.  The rotation position FA is the position to which the C-arm  9  rotates 25° in the LAO direction from the default position and 15° in the CRA direction therefrom. 
     First, once the operator pushes down the registration shifting switch  49 , the touch panel  43  shifts from the default mode to the registration mode (Step P 1 ). Referring to  FIG. 12 , once the touch panel  43  shifts to the registration mode, the display control element  71  displays the screen for the registration mode on the touch panel  43 . 
     Next, the operator selects the memory switches  55  that is the target in which the new rotation position information is registered (Step P 2 ). Here, the registration target is the memory switch  55   a,  so that the operator pushes down the memory switch  55   a.  As the trigger that is the action of selecting and pushing down the memory switches  55  and pushing down, the display control element  71  displays the additional information for identifying the selected memory switches  55  on the touch panel  43 . Referring to  FIG. 13 , according to the present Embodiment, the frame of the selected memory switch  55  (here, memory switch  55   a ) is displayed by the thick line to indicate corresponding to such an additional information. 
     In addition, referring to  FIG. 13 , once the memory switches  55  is selected to be the register target, the read-out element  69  reads out the rotation position information that is stored in the respective memories  63 - 65  in correspondence with the selected memory switch  55  and sends such information to the display control element  71 . The display control element  71  displays the respective read-out rotation position information in the memory selection switch  77 . As a result, referring to  FIG. 14 , the information of the rotation position F 1  is displayed in the memory selection switch  77   a.  As well, the information of the rotation positions F 2  and F 3  is displayed in the memory selection switch  77   b  and  77   c.    
     Once the memory switch  55  is selected, the operator confirms the rotation position information displayed in the respective memory selection switches  77  and selects the target memory to be overwritten (Step P 3 ). The target memory to be overwritten and registered is the third memory  65   a,  so that the memory selection switch  77  corresponding to the third memory  65   a  is selected and pushed down. Referring to  FIG. 15 , as the trigger that is the selection of the memory selection switch  77 , the display control element  71  displays the additional information for implying the selection target relative to the selected memory selection switch  77 . Referring to  FIG. 15 , the frame of the memory selection switch  77   c  is denoted by the thick line, so that the additional information can be pointed as well as the additional information Sp. 
     Once the memory selection switch  77  is selected, the operator selects either the direct registration mode or the manual registration mode using the registration setting selection switch  81  (Step P 4 ). Now, the direct registration mode to register the rotation position of the C-arm  9  at the present time is already selected at the present time, the operator pushes down the registration instruction switch  83  without operating the registration setting selection switch  81  (Step P 5 ). 
     Referring to  FIG. 15 , once the registration instruction switch  83  is pushed down, the information of indicating that such a pushing-down has been executed is displayed in the registration instruction switch  83  by the display control element  71  and also the confirmation key  87  is displayed thereby. Referring to  FIG. 16 , the operator operates the key for carrying on the registration (here, the key displayed as Yes) among the confirmation keys  87 , so that the memory control element  73  overwrites the information of the rotation position and stores therein relative to the third memory  65   a  in which the information of the rotation position F 3  is stored. When the touch panel  43  is returned to the default mode, the touch panel  43  shifts from the registration mode to the default mode along with pushing down the mode return switch  85 . 
     The rotation position of the C-arm  9  at the present time can be registered in corresponding with the memory switches  55  in the direct registration mode. Specifically, the information of the rotation position can be quickly registered while skipping the operation to confirm the accurate rotation position of the C-arm  9  at the present time. 
     The second switch  81   b  is pushed down at Step P 4  when the rotation position information is registered due to the manual registration mode, The display screen of the touch panel  43  is switched to the screen shown in  FIG. 17  by pushing down the second switch  81   b.  Specifically, the setting position display element  80  and the adjustment key  86  are displayed on the touch panel  43  instead of the current position display element  79 . The operator operates arbitrarily such as the adjustment key  86  to adjusts so that the rotation position information to be displayed in the setting position display element  80  is the rotation position FA. 
     As a specific example of the adjustment operation, the angle of the body axis direction (CRA/CAU) becomes adjustable by pushing down the body axis direction adjustment element  80   a  that is place in the right side of the setting position display element  80 . The degree of the angle in the body axis direction can be arbitrarily adjusted by arbitrarily operating the upward direction key or the downward direction key consisting of the adjustment keys  86  following pushing down the body axis direction adjustment element  80   a.  In addition, the angle of the body axis circumference direction (LAO/RAO) becomes adjustable by pushing down the body axis circumference direction adjustment element  80   b  that is place in the left side of the setting position display element  80 . 
     The operation of Step P 5  is executed following adjusting for displaying the information of the rotation position FA in the setting position display element  80 . Specifically, the operator pushes down the registration instruction switch  83  and the confirmation key  87 . The memory control element  73  overwrites the information of the rotation position FA displayed in the setting position display element  80  on the third memory  65   a  and stores thereon by operating the key for carrying on the registration among the confirmation keys  87 . 
     The C-arm  9  is not needed to be shifted to the actual target rotation position due to the manual registration mode. Consequently, when the information of the rotation position to be preregistered is known, the information of the rotation position can be further quickly registered in correspondence with the memory switches  55 . 
     &lt;Structure of the Editing Mode&gt; 
     When the procedural operation proceeds for the subject M, the action to acquire the X-ray images of the same region of interest from a plurality of different directions may be repeated. For example, the back-and-forth operation for the C-arm  9  is repeatedly progressed between the first rotation position Fp and the second rotation position Fs, which are defined based on the subject M or a kind of procedural operation. 
     When the back-and-forth operation is performed on the C-arm  9  between predetermined rotation positions, it is preferable that the auto-positioning operation is executed to cut the time needed for back-and-forth operation while temporally registering the information of the rotation position Fp and the information of the rotation position Fs. It is common that the first rotation position Fp and the second rotation position Fs are determined as the rotation positions at which the desired X-ray fluoroscopic images can be obtained by performing the X-ray fluoroscopy while shifting the C-arm  9  to a variety of rotation positions relative to the region of interest. 
     When the registration of the rotation position is needed in the short-term during proceeding the procedural operation, the operator switches the touch panel  43  to the edition mode and registers the information of the rotation position Fp and the rotation position Fs in correspondence with the second memory switch group M 2 . Now, the inventors set forth the configuration wherein the new rotation position information is temporarily stored in correspondence with the memory switch  57  in the edition mode 
     When overwritten with the new rotation position information in correspondence with the memory switches  57 , first the edition shifting switch  51  is pushed down to shift the touch panel  43  from the default mode to the edition mode. The display control element  71  changes the display screen of the touch panel  43  from the state referring to  FIG. 6  to the state referring to  FIG. 18  by shifting to the edition mode. 
     The touch panel  43  that shifts to the edition mode comprises a first memory switch group M 2 , a plurality of memory switches  57   a - 57   c  constituting the second memory switch group M 2 , a current position display element  89  and a mode return switch  91 . 
     The read-out element  69  reads out the rotation position information that is stored in the short-term memories  67   a - 67   c  in correspondence with the memory switches  57   a - 57   c  by shifting to the edition mode. The display control element  71  displays the rotation position information read out from the short-term memories  67   a - 67   c  in the respective memory switches  57   a - 57   c  in correspondence therewith. Specifically, the information of the rotation position F 21  is displayed in the memory switch  57   a.    
     When the information of the rotation position is not stored in the corresponding short-term memory  67 , the display control element  71  displays the additional information Rp indicating that the rotation position information is not registered in the appropriate memory switch  57 . According to the present Embodiment, the figure (circle plus sign) combining a plus sign (+) and a circle surrounding such a plus sign is applied to the additional information Rp. 
     Referring to  FIG. 8 , the rotation position information is not registered yet in the short-term memory  67   b  and in the short-term memory  67   c.  Consequently, the display control element  71  displays the additional information Rp in the memory switch  57   h  and the memory switch  57   c.  The operator visually recognizes the information displayed in the memory switches  57   a - 57   c  and thereby can intuitively understand if the rotation position information exists or not. 
     The current position information display element  89  displays the information of the rotation position of the C-arm  9  at the present time that the rotation position detection element  33  detects. Referring to  FIG. 18 , the current position display element  89  displays the first rotation position Fp (LAO) 40°, CAU 40°). The mode return switch  91  is the switch through which an instruction for the touch panel  43  to return from the edition mode to the default mode is input. 
     &lt;Operation of the Edition Mode&gt; 
     Here, the inventors set forth the operation to register the new rotation position information with the memory switches  57  in the edition mode.  FIG. 9C  is the flow chart illustrating the operation to register the new rotation position information in the memory switches  57 . Here, the inventors set forth the case in which the information of the rotation position Fp and the information of the rotation position Fs (RAO40°, CAU40°) are temporarily registered relative to the memory switches  57 . According to the present Embodiment, no rotation position information in the memory switch  57   b  and  57   c  is registered, the information of the rotation position Fp is deemed to register in correspondence with the memory switch  57   c  and the information of the rotation position Fp is deemed to register in correspondence with the memory switch  57   c.    
     First, the operator pushes down the edition shifting switch  51  to shift the display screen of the touch panel  43  shifts from the default mode to the edition mode (Step T 1 ). Referring to such a  FIG. 18 , once the touch panel  43  shifts to the registration mode, the display control element  71  displays the screen for the edition mode on the touch panel  43 . 
     Next, the operator selects the memory switches  57  that are the targets in which the new rotation position information is registered (Step T 2 ). The target to register the rotation position Fp displayed in the current position display element  89  is the short-term memory  67   b  corresponding to the memory switch  57   b,  so that the operator selects the memory switch  57   b.    
     The operator pushes down the selected memory switches  57  following selection of the memory switches  57  (Step T 3 ). Referring to FIG,  19 , the memory switches  57  are pushed down and then the information of the rotation position of the C-arm  9 , which the rotation position detection element  33  detects, are sent to the memory control element  73 . In addition, the information identifying the short-term memory  67  in correspondence with the pushed-down memory switches  57  are sent to the memory control element  73 . 
     The memory control element  73  registers the information of the rotation position of the C-arm  9  at the present time relative to the short-term memory  67  corresponding to the pushed-down memory switches  57  based on the received information. Specifically, the operator pushes down the memory switch  57   b  so that the information of the rotation position Fp is stored in the short-term memory  67   b.  Once the information of the rotation position Fp is registered, the information of the rotation position Fp instead of the additional information Rp is displayed in the memory switch  57   b.    
     In addition, when the information of the rotation position Fs is registered in correspondence with the memory switches  57 , the operator pushes down the memory switch  57   c  following rotating the C-arm  9  to the rotation position Fs. Referring to  FIG. 20 , the information of the rotation position Fs is displayed in the current position display element  89  due to rotating the C-arm  9  to the rotation position Fs. The information of the rotation position Fs that is the rotation position of the C-arm  9  at the present time are stored in the short-term memory  67   c  due to pushing down the memory switch  57   c  in the edition mode. Once the rotation position Fp and the rotation position Fs that are the targets to be registered are stored, the edition mode operation ends. Once the operator pushes down the mode return switch  91 , the touch panel  43  returns to the default mode from the edition mode. 
     The operator alternatively shifts the C-arm  9  to the rotation position Fp and to the rotation position Fs by the auto-positioning operation following return to the default mode. Specifically, the operator pushes down the memory switch  57   b  while the touch panel  43  is in the state of the default mode (Step S 1 , S 2 ). The additional information Sp is displayed in the memory switch  57   b  by pushing down the memory switch  57   b  and it is indicated that the memory switch  57   b  is in the selected state (Step S 3 ). The rotation instruction switch  45  is pushed down in the state in which the additional information Sp is displayed in the memory switch  57   b,  by which the C-arm  9  rotates to the rotation position Fp (Step S 4 ). 
     When the C-arm  9  rotates from the rotation position Fp to the rotation position Fs, the operator pushes down the memory switch  57   c.  And the rotation instruction switch  45  is pushed down in the state in which the additional information Sp is displayed in the memory switch  57   c,  by which the C-arm  9  rotates to the rotation position Fs. The operator alternatively rotates the C-arm  9  to the rotation position Fp and to the rotation position Fs by the auto-positioning operation while performing the X-ray fluoroscopy, so that the procedural operation can be quickly and adequately progressed referring to the X-ray image that is obtained by the X-ray fluoroscopy. 
     When the procedural operation or the examination for the subject M ends, the operator pushed down the end instruction switch  47  installed to the console  39 . Referring to  FIG. 21 , the position information erasing element  75  is activated by the operation for pushing down the end instruction switch  47  as the trigger. The position information erasing element  75  erases all information of the rotation position information stored in correspondence with the respective memory switches  57 . Specifically, the position information erasing element  75  erases the respective rotation position information stored in the short-term memories  67   a - 67   c.    
     The information of the rotation position Fp and the rotation position Fs is temporarily stored in the short-term memory  67  by using such an edition mode as far as the duration in which the procedural operation on the subject M is being performed. In addition, no operation on the registration instruction switch  83  and the confirmation key  87  are required in the edition mode, which is different from the registration mode. Specifically, the rotation position information displayed in the current position display element  89  are stored in the short-term memories  67  according to the simple operation in which the memory switches  57  corresponding to the short-term memories  67 , in which the rotation position information is temporarily stored, are pushed down. Consequently, the edition mode to register on the second memory switch group M 2  is applied, so that the necessary steps needed to register the rotation position can be cut down. 
     The end instruction switch  47  is mandatory to end the procedural operation for the subject M. Therefore, a series of operations required to end the procedural operation for the subject M is executed, and thereby the control to erase the information of the short-term memories  67   a - 67   c  can be absolutely executed with the operation of the end instruction switch  47  as the trigger. Therefore, the incident of forgetting to erase the information of the rotation position Fp and the rotation position Fs, which are important only in the procedural operation for the subject M, can be avoided. 
     The information of the rotation position Fp and the rotation position Fs is automatically erased when the procedural operation for the subject M ends, so that the unregistered state comes into which the rotation position information that is absolutely not registered in the respective short-term memories  67  corresponding to the respective memory switches  57  when the X-ray fluoroscopic imaging apparatus  1  is applied to the next different subject N. Consequently, it can be avoided that the operator hesitates to overwrite such short-term memories  67  with the rotation position information being registered due to remaining the past-registered information of the rotation positions in the short-term memories  67 . 
     (Effects of the Aspect of Embodiment) 
     (Term) The X-ray fluoroscopic imaging apparatus  1  according to the present Embodiment comprises: an X-ray tube  5  that irradiates an X-ray to a subject M; an X-ray detector  7  that is in place facing the X-ray tube  5  detects the X-ray transmitting the subject M; a C-arm  9  that supports the X-ray tube  5  and the X-ray detector  7  to face each other and is rotatable around respective two axes that are orthogonal to each other; a rotation position detection element  33  that detects an information related to a rotation direction and a rotation angle around the respective axes of the C-arm  9  as rotation position information; a plurality of memory switches  55 ; a rotation position memory storage element  61  that stores the rotation position information in correspondence with any of memory switches  55 ; a touch panel  43  that displays the rotation position information that are stored in correspondence with such memory switches  55  selected by selection any of the memory switches  55 ; and a rotation instruction switch  45  that rotates the C-arm  9  in the rotation direction and with the rotation angle in correspondence with the rotation position information that is displayed in the touch panel  43 , wherein the rotation position memory storage element  61  is configured to store a plurality of rotation position information in correspondence with the respective memory switches  55 , and the touch panel  43  is configured to display any of the plurality of rotation position information stored in correspondence with the memory switches  55  in a predetermined display manner due to operating the memory switches  55  in the predetermined operation manner. 
     Referring to  FIG. 22  or  FIG. 23  the inventors set forth an effect due to the fluoroscopic imaging apparatus  1  described in Term 1.  FIG. 22  is a view illustrating a console  101  applied to a conventional X-ray fluoroscopic imaging apparatus. 
     The console  101  comprises a center switch  103  having a displayed humanoid symbol and eight memory switches  105  placed around the center switch  103 . Each of the memory switches  105  is distinguished as the respective memory switches  105   a - 105   h  from one another. In addition, the console  101  comprises extra memory switches  107  that are reserved memory switches. The respective extra memory switches  107  are in place away from the center switch  103 . 
     It is defined so that the positional relationship between the memory switches  105   a - 105   h  and the center switch  103  coincides with the positional relationship between the rotation position of the C-arm and the subject loaded on the table. Specifically, the rotation position toward LAO direction and CRA direction relative to the subject is stored in correspondence with the memory switch  105   a,  that is in place at the upper left side of the center switch  103 . 
     The target memory switch  105  stored in correspondence with such a rotation position is decided in accordance with the positional relationship of the rotation position relative to the subject, so that the memory switch  105  to be selected on executing the auto-positioning operation can be intuitively understood. In addition, the rotation position toward the RAO direction and the CRA direction is stored in the memory switch  105  and after a while the auto-positioning for the C-arm  9  to such a rotation position may be performed. In such a case, it is intuitively understandable that such rotation position information is registered in advance in the memory switch  105   f  that is in place at the lower left side of the center switch  103 . 
     Here, one rotation position information is stored in correspondence with one memory switch therefor when executing the auto-positioning operation using the conventional X-ray fluoroscopic imaging apparatus. Therefore, when more than two rotation positions toward the same direction are registered in advance, it is difficult to store the respective rotation positions in correspondence with the memory switches  105  to be intuitively understood. 
     For example, it is given that the information of the rotation position M 1  for rotating in the LAO direction and the CRA direction is already stored in correspondence with the memory switch  105   a.  In such a scenario, the new information of the rotation position M 2  for rotating in the LAO cannot be stored in correspondence with the memory switch  105   a.  In case of forcibly storing the information of the rotation position M 2  in correspondence with memory switch  105   a,  at least the information of the rotation position M 1  already stored is subject to be lost. 
     In addition, when executing the operation to overwrite the information of the rotation position M 1  with the information of the rotation position M 2  according to the conventional aspect, such an overwriting and registration operation is required to be the different operation therefrom in comparison with the operation in which the new rotation position information is registered for the memory switches  105  in which the rotation position information is not yet registered. For example, the operation for newly registering the rotation position is the operation in which the memory switches  105  are pushed down for a short period of time, whereas the operation for overwriting and registering needs a complex operation e.g., the operation in which the memory switches  105  are being pushed down for a long period of time or the memory switches  105  and the other switch are simultaneously pushed down. As a result, in the case of overwriting and registering, it is concerned that the operation may need a longer period of time, or an erroneous operation may take place. 
     According to the conventional configuration, when the information of the rotation position M 2  is registered while storing the information of the rotation position M 1 , it is common that the operation for storing information of the rotation position M 2  in correspondence with the extra switch  107  is executed. Whereas the positional relationship between the extra switch  107  and the center switch  103  is not reflected in the positional relationship between the subject and the rotation position M 2 . 
     Consequently, when the C-arm  9  rotates to the rotation position M 2  again due to the auto-positioning operation following registration of the information of the rotation position M 2 , the operator may be confused about which switch should be selected to read out the information of the rotation position M 2 . As a result, it takes a longer time required for the auto-positioning operation, so that it is concerned that the progression of the quick procedural operation can be disturbed. 
     Such issues are particularly remarkable when the procedural operation due to auto-positioning operations is carried on a number of subjects. Specifically, the incident in which the predetermined rotation positions are registered may take place every procedural operation that is carried on the subject. Therefore, provided the procedural operation is carried on a number of subjects, the rotation position information is already registered in the predetermined memory switches  105 , so that the incident in which no information of the new rotation position can be registered takes place promptly. 
     It is considered that such a configuration, in which a plurality of memory switches  105   a - 105   h  is in place, may be the solution for the problem as to an immediate occurrence of the incident in which no information of the new rotation position can be registered in the memory switches  105 . Specifically, a plurality of the memory switches  105   a  is in place and a plurality of memory switches  105   b - 105   h  are also respectively in place. 
     However, provided multiple sets of the memory switches  105   a - 105   h  are in place while keeping the positional relationship with the center switch  103 , the memory switches  105   a - 105   h  must be in place as illustrated in  FIG. 23 . Specifically, multiple sets of the memory switches  105   a - 105   h  are in place so as to expand radially from the center switch  103  as the center thereof, so that the console  101  must be made much larger to place all memory switches  105 . As a result, it is concerned about the problem in which it is difficult to secure the installation space for the console  101 . 
     Compared with the conventional configuration, the X-ray fluoroscopic imaging apparatus, according to Term 1 comprises the touch panel  43 , a plurality of memory switches  55 , the rotation position memory storage element  61  and the rotation instruction switch  45 . The touch-panel  43  displays the rotation position information that is stored in correspondence with such memory switches  55  selected by selecting any of memory switches  55 . The rotation position memory storage element  61  stores the rotation position information of the C-arm  9  in correspondence with any of the memory switches  55  and is configured to store a plurality of rotation position information corresponding to the respective memory switches  55 . The touch-panel  43  is configured to display any of the plurality of rotation position information stored in correspondence with such memory switches  55  in the predetermined manner due to the operation of the memory switches  55  in the predetermined operation manner. 
     Specifically, the X-ray fluoroscopic imaging apparatus  1  is capable of storing every one memory switch  55  in correspondence with a plurality of rotation positions. Consequently, while lowering the number of the memory switches apparatus, a larger number of the rotation position information can be stored for a long time in correspondence with the memory switches  55 . 
     A plurality of the rotation position information that is respectively stored in corresponding to each one of memory switches  55  can be displayed in the predetermined display manner by operating the memory switches  55  placed in the touch panel  43  in the predetermined operation manner. Specifically, the information of the respective rotation positions can be selectively read out and displayed corresponding to the operation manner of the memory switch  55  even when a plurality of the rotation positions is stored in correspondence with one memory switch  55 . 
     And the C-arm  9  is capable of rotating in the rotation direction and with the rotation angle respectively corresponding to the rotation position information that is displayed in the touch-panel  43  due to the operation of the rotation switch  45 . Accordingly, an operation is now achievable, wherein the C-arm  9  is rotated to such a rotation position by selecting the one rotation position from a plurality of stored rotation positions with regard to the configuration in which the plurality of the rotation positions are stored in correspondence with one memory switch  55 . 
     Particularly, when the operation manner for the memory switches  55  is the number of pushing down the memory switches  55 , one of the multiple rotation position information stored in correspondence with such memory switches  55  is displayed on the touch panel  43  in order. Once the desired rotation position information is displayed on the touch panel  43 , the operator can rotate the C-arm  9  to such a rotation position by operating the rotation instruction switch  45 . In such a case, the auto-positioning operation in which the C-arm  9  rotates to the desired rotation position can be brought in reality by a simple operation, i.e., pushing down the respective switches. Specifically, no complex operation e.g., the operation of pushing down a switch for a long time or the operation of simultaneously pushing down a plurality of switches, is required, so that the auto-positioning operation can be executed exactly in a short period of time. 
     (Term 2) In addition. the X-ray fluoroscopic imaging apparatus according to Term 1, the respective memory switches  55  are in place at the position corresponding to the rotation direction stored in correspondence with the memory switches as the basis for the reference region indicating the position of the subject M. 
     With regard the X-ray fluoroscopic imaging apparatus according to Term 2, the position, at which the respective memory switches  55  are in place on the basis of the center switch  53 , is defined so as to correspond to the direction of the rotation position stored in correspondence with the memory switches  55  on the basis of the rotation position F 0  stored in correspondence with the center switch  53 . 
     According to such a configuration, based on the direction in which the memory switches  55  are in place on the basis of the position at which the center switch  53  is in place, the operator can intuitively understand that the rotation position stored in correspondence with such memory switches  55  is in which direction on the basis of the initial rotation position F 0  in correspondence with the center switch  53 . Therefore, the time needed for the auto-positioning operation can be reduced, and an incident of an error operation during the auto-positioning operation can be absolutely avoided. 
     For example, the memory switches  55   h  are in place at the lower right side of the center switch  51 . Consequently, the operator can intuitively understand that the information of the rotation position that rotates in the lower right direction, i.e., the RAO direction and the CAU direction on basis of the initial rotation position F 0  is stored in the memory switch  55   h  in correspondence therewith. Therefore, the operator can quickly select the switch, in which the information of the target rotation position is stored in correspondence therewith, from a plurality of memory switches  55   a - 55   h.  In addition, when newly registering the information of the rotation position, the operator can quickly select the memory switches  55  that are the targets to be stored in correspondence with such information of the rotation position. 
     (Term 3) The X-ray fluoroscopic imaging apparatus according to the second aspect of the present Embodiment comprises: an X-ray tube  5  that irradiates an X-ray to a subject; an X-ray detector  7  that is in place facing the X-ray tube  5  detects the X-ray transmitting the subject M; a C-arm  9  that supports the X-ray tube  5  and the X-ray detector  7  to face each other and is rotatable around respective two axes that are orthogonal to each other; a rotation position detection element  33  that detects information related to a rotation direction and a rotation angle around the respective axes of the C-arm  9  as rotation position information; a plurality of memory switches  57 ; a rotation position memory storage element  61  that stores the rotation position information in correspondence with any of memory switches  57 ; a touch panel  43  that displays the rotation position information that are stored in correspondence with such memory switches  57  selected by selection any of the memory switches  57 ; and a. rotation instruction switch  45  that rotates the C-arm in the rotation direction and with the rotation angle in correspondence with the rotation position information that are displayed in the touch panel  43 ; and a position information erasing element  75  that erases the rotation position information stored in correspondence with the respective memory switches  57  due to the operation as a trigger that instructs the specific step specified in advance in a series of examination steps relative to the subject M. 
     The X-ray fluoroscopic imaging apparatus, according to Term 3, comprises the touch panel  43 , a plurality of memory switches  57 , the rotation position memory storage element  61 , the rotation instruction element  45  and the rotation position information erasing element  75 . The touch panel  43  displays the rotation position information that is stored in correspondence with such memory switches  57  selected by selecting any of memory switches  57 . The rotation position memory storage element  61  stores the rotation position information of the C-arm  9  in correspondence with any of the memory switches  57 . 
     Once the desired rotation position information stored in correspondence with such memory switches  57  is displayed on the touch panel  43 , the operator selects the memory switches  57 , and rotates the C-arm  9  to such a rotation position by operating the rotation instruction switch  45 . In such a case, the auto-positioning operation in which the C-arm  9  rotates to the desired rotation position can be brought in reality by a simple operation, i.e., pushing down the respective switches. Specifically, no complex operation e.g., the operation of pushing down a switch for a long time or the operation of simultaneously pushing down a plurality of switches, is required, so that the auto-positioning operation can be executed exactly in a short period of time. 
     And once the operation for instructing a specific predetermined process of a series of examination processes relative to the subject M is performed, the rotation position information erasing element  75  erases the rotation position information stored in correspondence with the respective memory switches  57  using such an operation as a trigger. In such a configuration, once a series of examination processes relative to the subject M is completed, the rotation position information stored in correspondence with the respective memory switches  57  are automatically erased. In other words, the memories of the rotation position information in correspondence with the memory switches  57  are temporary or stored in a short period of time. Specifically, the rotation position information stored in correspondence with the memory switches  57  when the examination is carried on the subject are stored only as far as the duration in which the examination is ongoing on such a subject. 
     Consequently, at the time when the examination for a new subject starts, no information of the rotation position stored while the examination for the previous subject is carried on are left in the memory switches  57 . Therefore, the incident in which the operation is incapable of storing the new rotation position information in correspondence with such memory switches  57  or the incident of hesitation in the operation to store due to remaining the rotation position information stored during the past examination in the memory switches  57  can be avoided. 
     In such a way, even when a number of rotation positions are needed to be stored since a number of subjects are examined, the information of the rotation positions is erased whenever the examination relative to the subject ends. Therefore, it is not required to forever and continuously store the rotation position information with regard to all subjects in correspondence with the respective individual memory switches  57 . Specifically, the number of the memory switches  57  is limited to the number of the rotation positions to be stored mandatory with regard to the examination relative to each subject. Therefore, while reducing the number of the memory switches  57  installed to the X-ray fluoroscopic imaging apparatus  1 , the examination for a number of subjects can be adequately performed using the auto-positioning operation. 
     (Term 4) In addition, the X-ray fluoroscopic imaging apparatus according to Term 3 comprises an edition shifting switch  51  that executes shilling to the edition mode to store the rotation position information in the memory switches  51  by the rotation position memory storing element  61 , wherein the rotation position memory storing element  61  stores the rotation direction and the rotation angle of the C-arm  9  as the rotation position information in correspondence with the memory switches  57  by operating any of the memory switches  57  in the state of shifting to the edition mode. 
     According to the X-ray fluoroscopic imaging apparatus described in Term 4, the rotation position memory storing element  61  stores the rotation direction and the rotation angle of the C-arm  9  at the time when the operation is executed in correspondence with the memory switches  57  as the rotation position information by operating any of the memory switches  57 . Therefore, once it is found that the desired X-ray image is obtained by the X-ray fluoroscopic imaging, the rotation position information of the C-arm  9 , at the time when the X-ray image is obtained, is automatically stored by operating the memory switches  57 . Specifically, the rotation position information corresponding to the X-ray image imaging condition is exactly and quickly stored, so that the rotation position of the C-arm  9  required to obtain such an X-ray image can be easily and precisely reproduced later. 
     (Term 5) In addition, the X-ray fluoroscopic imaging apparatus, according to any one term of Term 1 to Term 4, comprises the display control element  71  displays the latest memory switch operated by the operator among a plurality of memory switches in a different manner from other memory switches. 
     According to the X-ray fluoroscopic imaging apparatus of Term 5, the latest memory switches  55  (or memory switches  57 ) operated by the operator are displayed in the different manner from other memory switches  55  (or memory switches  57 ) by the display control element  71 . In such a configuration, the operator can absolutely identify the latest operated memory switch from a plurality of the memory switches. Therefore, an erroneous operation in the auto-positioning, operation can be avoided and the time needed for such an operation can be further shortened, 
     &lt;Other Embodiments&gt; 
     Specifically, the aspects of the Embodiment disclosed at this time are examples and not limited thereto in any points. The scope of the present invention includes the claims and all alternatives and equivalents thereof within the scope thereof. For example, the present invention can be implemented in the below alternative Embodiment. 
     (1) According to Embodiment set forth above, the console  39  comprises the first memory switch group M 1  and the second memory switch group M 2 , but not limited thereto. Specifically, the console  39  may comprise only the first memory switch group M 1  instead of both first memory switch group M 1  and second memory switch group M 2 , or only the second memory switch group M 2  instead of both thereof. 
     (2) In the above Embodiments or the alternative Embodiment, for example, the configuration in which the direct registration mode and the manual registration mode is selectively applied in the registration mode using the first memory switch group M 1  is disclosed, but only either one mode may be applied. In addition, in the edition mode using second memory switch group M 2 , Embodiment using only i,e., the direct registration mode in which the rotation position information of the C-arm  9  at the present, time is stored every time when the memory switches  57  are pushed down is illustrated, but not limited thereto. Specifically, the manual registration mode may be selected even in the edition mode. 
     (3) In the above Embodiments or the alternative Embodiment, the components of a variety of switches installed to the console  39  may be arbitrarily modified and arbitrarily changed to e.g., such as an icon displayed on the touch panel, a dial-type switch or a pushbutton switch. 
       FIG. 24  is a schematic diagram illustrating an example of the console  39  of an alternative Embodiment. In the console  39  of the alternative Embodiment, the center switch  53 , the memory switches  55  and the memory switches  57  are all pushbutton switches. Specifically, the console  39  of the alternative Embodiment has not the touch panel  43 . 
     In addition, the console  39  of the alternative Embodiment comprises a rotation position display monitor  93 . The rotation position display monitor  93  displays such as the information of the rotation position read out by the read-out element  69  due to pushing down the memory switches  55  or the memory switches  57  and a variety of additional information added by the display control element  71 . In the console  39  of the alternative Embodiment, a variety of switches such as the registration shifting switch  49 , the edition shifting switch  51 , the registration instruction switch  83 , the mode returning switch  85  are also pushbutton switches. 
     The inventors set forth the operation using the console  39  according to the alternative Embodiment. For example, the operator pushes down the memory switch  55   d  three times when executing an auto-positioning operation to the rotation position F 12  in the default mode. Due to such push-down operation, the read-out element  69  reads out the information of the rotation position F 12  from the third memory switch  65   d  and the display control element  71  displays such rotation position information along with the additional information Qt on the rotation position display monitor  93 . In addition, the display control element  71  displays the additional information Sp relative to the memory switch  55   d.    
     In the alternative Embodiment, the additional information Sp is the information that instructs displaying the latest selected memory switch  55   d  in the different color from other memory switches  55  thereof. The operator confirms the information of the rotation position F 12  displayed on the rotation position display monitor  93  and then pushes down the rotation instruction switch  45 . The C-arm  9  rotates to the rotation position F 12  due to the operation for pushing down the rotation instruction switch  45 . 
     In such a way, even if the console  39  does not have the touch panel  43 , the operation related to the respective modes can be executed using a variety of switches and the rotation position display monitor  93 . 
     (4) In the Embodiments or the alternative Embodiment set forth above, the center switch  53  is configured to be capable of storing in correspondence with only one rotation position but may be configured to be capable of storing a plurality of the rotation positions as well as the memory switches  55 . 
     (5) In the Embodiments or the alternative Embodiment set forth above, the operation as the trigger for the position information erasing element  75  to be activated is illustrated as e.g., pushing down the end instruction switch  51  to end the procedural operation for the subject M, but not limited thereto. For the other example, an operation of turning on or off the main power source for the X-ray fluoroscopic imaging apparatus  1  or an operation of activating the position information erasing element  75  may be applied to the trigger to start the procedural operation for the subject M. Specifically, any mandatory operation in a series of the operations to complete the procedural operation for the subject M can be arbitrarily applied to such a trigger. 
     (6) In the Embodiments or the alternative Embodiment set forth above, the respective memory switches  55   a - 55   h  are in correspondence with three memories  63 - 65  and three rotation positions can be registered as a maximum. Regardless, the maximum number of the rotation position registrable to the respective memory switches  55   a - 55   h  is not limited to three and may be arbitrarily changed. Specifically, the number of the registrable rotation positions can be arbitrarily adjusted by arbitrarily changing the number of memories in correspondence with the memory switches  55 . In addition, the maximum number of the registrable rotation positions is not limited to be the same as for all memory switches  55   a - 55   h.  For example, the memory switch  55   a  is configured to have the two registrable rotation positions as a maximum, and on the other hand the memory switch  55   g  may be configured to have the four registrable rotation positions as a maximum. 
     (7) In the Embodiments or the alternative Embodiment set forth above, the operation of pushing down the memory switches  57  that are targets for the registration operation following switching the default mode referring to  FIG. 10  to the edition mode referring to  FIG. 18  is illustrated as the method of registering the information of the rotation position of the C-arm  9  in the memory switches  57 , but not limited thereto. For example, the configuration in which the rotation position information is registered by pushing down the memory switches  57  in the default mode state referring to  FIG. 10  may be adopted. 
     For a specific example, in the default mode state, the information of the rotation position of the C-arm  9  at the time when such push-down operation is executed is stored in correspondence with the memory switch  57   b  by pushing down the memory switch  57   b  to which the additional information Rp is added. Providing the rotation position information to be registrable to the memory switches  57  in the default mode, the operation for registering the rotation position in the memory switches  57  can be further simplified. 
     (8) In the Embodiments or the alternative Embodiment set forth above, it is illustrated that the additional information Qt includes e,g., the information identifying the number of the rotation positions registered in the memory switches  55  but also may include the information indicating the number of the memories  63 - 65  in correspondence with the memory switches  55 . Specifically, in Embodiment, the number of the circular symbols consisting of the additional information Qt indicates the number of the rotation positions registered in the memory switches  55  at the present time. Instead, the number of the circular symbols consisting of the additional information Qt may indicate the number of the memories  63 -  65  in correspondence with the memory switches  55  (upper limit number of the rotation positions registrable in the memory switches  55 ). 
     REFERENCE OF SIGNS 
     
         
           1 . X-ray fluoroscopic imaging apparatus 
           3  Table 
           5  X-ray tube 
           7  X-ray detector 
           9  C-arm (support mechanism) 
           17  Collimator 
           29  X-ray irradiation control element 
           30  Image generation element 
           31  image display element 
           33  Rotation position detection element 
           35  Main control element 
           37  Memory storage element 
           39  Console 
           41  Arm operation lever 
           43  Touch panel 
           45  Rotation instruction switch (Rotation instruction element) 
           47  End instruction switch 
           49  Registration shifting switch 
           51  Edition shifting switch 
           53  Center switch 
           55  Memory switch 
           57  Memory switch 
           61  Rotation position memory storage element 
           63  First memory 
           64  Second memory 
           65  Third memory 
           67  Short term memory 
           69  Read-out element 
           71  Display control element (Selected memory switch display mechanism) 
           73  Memory control element 
           75  Position information erasing element (Rotation position information erasing element) 
           77  Memory selection switch 
           79  Present position display element 
           83  Registration instruction switch 
           85  Mode return switch 
           89  Present position display element 
           91  Mode return switch 
           93  Rotation position display monitor 
       
    
     Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it will be apparent to those skills that the invention is not limited to those precise embodiments, and that various modifications and variations can be made in the presently disclosed system without departing from the scope or spirit of the invention. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they conic within the scope of the appended claims and their equivalents.