Patent Publication Number: US-2012046971-A1

Title: Method and system for imaging patients with a personal medical device

Description:
The present application relates generally to the medical imaging arts. More specifically, it provides a method and system for the detection of personal medical devices and for conducting medical imaging procedures on patients with a personal medical device. The application subject matter finds use at least with computed tomography (CT) imaging and will be described with particular reference thereto. However, it also has more general application with other imaging methods and in other arts, such as x-ray, fluoroscopy, magnetic resonance (MR), single-photon emission computed tomography (SPECT), positron emission tomography (PET), and ultrasound (US). 
     Recent studies have demonstrated the potential for interaction between personal medical devices and imaging radiation, such as x-ray radiation used in CT. Such personal medical devices include, but are not limited to, cardiac rhythm management devices, defibrillators, neurostimulators, drug infusion pumps (e.g., insulin pumps), cochlear implants, and retinal implants. X-ray radiation may interfere with the operation of a personal medical device or cause the device to malfunction. The interactions with x-ray radiation that may occur with these devices during CT scanning include the generation of spurious signals (e.g., cardiac defibrillation pulses), the misinterpretation or misdetection of device signals as actual physiological signals, and the resetting or reprogramming of the settings of the personal medical device. Each of these possible interactions may potentially result in adverse events. 
     At present, the likelihood of adverse events related to the x-ray induced personal medical device interference and/or malfunction is not completely understood or documented. Currently, most registered CT technologists have limited knowledge regarding personal medical devices. In addition, the type and location of personal medical devices varies greatly from patient to patient. There is also significant interpatient variation of the clinical factors exhibited by a patient that may indicate the presence of a personal medical device. 
     For the foregoing reasons and other reasons, it is desirable to provide a method and system for detecting the presence of a personal medical device and for gathering information regarding the device. In addition, it is desirable to provide a method and system to adapt or customize medical imaging procedures to diminish the risk of x-ray radiation interfering with a personal medical device. It is also desirable to provide a method and system to balance the image quality obtained by a particular medical imaging procedure with the risk of possible device interference or malfunction if it is necessary to scan over the personal medical device. Finally, it is also desirable to provide a system for interfacing with health record databases, regulatory databases, medical device databases, or other types of databases to gather information regarding a particular patient&#39;s personal medical device. 
     Aspects of the present invention address these matters, and others. 
     According to one aspect of the present invention, a method and system are provided for detecting the presence of a personal medical device within a patient. According to another aspect of the present invention, a method and system are provided for determining the location and type of the personal medical device as well as other characteristics of the device. According to another aspect of the invention, a method and system are provided for adapting or customizing a medical imaging procedure to avoid interfering with a personal medical device or to diminish the risk of device interference or malfunction. According to yet another aspect of the invention, a method and system are provided for balancing the image quality obtained by a particular medical imaging procedure with the risk of possible interference with a personal medical device if it is necessary to scan over a personal medical device. According to another aspect of the present invention, a method and system are provided for interfacing with health record databases, regulatory databases, medical device databases, or other types of databases to gather information regarding a particular patient&#39;s personal medical device and to update said databases with additional information regarding the personal medical device if any is gathered. 
     Still further aspects of the present invention will be appreciated by those of ordinary skill in the art upon reading and understanding the following detailed description. Numerous additional advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of preferred embodiments. 
    
    
     
       The invention may take form in various components and arrangements of components, and in various process operations and arrangements of process operations. The drawings are only for the purpose of illustrating preferred embodiments and are not to be construed as limiting the invention. 
         FIG. 1  is a schematic view of an exemplary CT imaging system according to an embodiment of the present invention; 
         FIG. 2  is a schematic view of an exemplary medical imaging network according to an embodiment of the present invention; 
         FIG. 3  depicts a medical imaging method according to an embodiment of the present invention; 
         FIG. 4A  is an exemplary reconstructed CT scout scan image generated by a software program showing an implanted cardiac rhythm management device (ICMRD) and illustrating a planned scanned range that includes the ICMRD; and 
         FIG. 4B  is an exemplary reconstructed CT scout scan image generated by a software program according to one aspect of the present invention (of the same scout scan image of  FIG. 4A ) where the ICMRD has been detected and highlighted in the reconstructed CT image and illustrating a planned scan range that has been adjusted to diminish the risk of interference with the ICMRD. 
     
    
    
     Currently, many different kinds of imaging systems are used to obtain medical images. These kinds of imaging systems include CT, PET, SPECT, MRI, and other imaging systems. An exemplary CT imaging system  100  is illustrated in  FIG. 1 . As already mentioned, however, the imaging method and system disclosed herein also have application in connection with various other kinds of imaging systems or combinations of imaging systems other than the types expressly discussed herein. 
     As illustrated in  FIG. 1 , the exemplary CT imaging system  100  includes a CT imaging device  102 . A representative subject to be imaged is shown at  104  in  FIG. 1 , partially received in an aperture  106  of the CT imaging device  102 . The exemplary CT imaging system  100  also includes a memory  110 , image processor  120 , medical device module  130 , display  140  and user input  150 . The image processor  120  receives x-ray data from the CT imaging device  102  to generate CT images. The x-ray image data obtained by the CT imaging device  102  is stored in the memory  110 . The x-ray image data stored in the memory  110  is processed by the imaging data processor  120 . The processor  120  generates an image of the imaged subject  104 , based on the x-ray image data, according to a mathematical algorithm or algorithms. The image can be displayed on an associated display  140 . A user input  150  may be provided for a user to control the components of the CT imaging system  100 . The various components of the CT imaging system  100 , including the medical device module  130 , may be integral with the CT imaging device  102  or located remotely from the CT imaging device  102 . 
     The medical device module  130  is adapted to obtain patient data regarding a patient and analyze the patient data to determine information regarding any personal medical device(s) a patient has. In various embodiments of the CT imaging system  100 , the medical device module  130  is adapted to interface with a variety of information databases. An exemplary medical imaging network  200  is illustrated in  FIG. 2 . As shown in  FIG. 2 , the medical device module  130  of the exemplary embodiment is adapted to interface with electronic medical records (“EMR”)  210 , hospital information systems (“HIS”)  220 , radiology information systems (“RIS”)  230  and picture archiving and communication systems (“PACS”)  240 . As shown in  FIG. 2 , the medical device module  130  of the exemplary embodiment is also adapted to interface with databases provided and/or maintained by medical device manufacturers  250 , medical imaging scanner manufacturers  260  and/or regulatory agencies  270 . The medical device module  130  may also be adapted to interface with various other databases or collections of information in additional embodiments. It should be understood that in various embodiments of the CT imaging system  100 , the medical device module  130  does not interface with any databases. In additional embodiments of the CT imaging system  100 , the medical device module  130  may interface with one or more of the databases set forth in  FIG. 2 , but may not interface with all of these databases. 
     In various embodiments of the CT imaging system  100 , the medical device module  130  is adapted to analyze image data to determine the presence of a personal medical device. As used herein, “personal medical device” shall mean any medical device that is implanted fully or partially within a patient or is located externally and carried by or adhered to a patient, including but not limited to cardiac rhythm management devices, defibrillators, neurostimulators, drug infusion pumps (e.g., insulin pumps), cochlear implants, and retinal implants. The medical device module  130  employs a mathematical algorithm such as a thresholding, connected-component analysis, generalized Hough transform (GHT), model-based segmentation algorithm, or other suitable algorithm or algorithms to analyze image data for the presence of a personal medical device. The image data analyzed by the medical device module  130  may be obtained from a two-dimensional or three-dimensional scout scan (i.e., surview scan) or from a full scan. In various embodiments of the CT imaging system  100 , the medical device module  130  performs this analysis on image data that is acquired from a patient during a current imaging procedure (and stored in the memory  110  of the CT imaging system  100  or in some other location) or on image data that was previously obtained from the patient during prior imaging procedure(s) and stored in the picture archiving and communication system  240  or in some other location. The image data that is analyzed by the medical device module  130  to determine the presence of a personal medical device may also be used for attenuation correction. 
     In various embodiments of the CT imaging system  100 , the medical device module  130  is adapted to determine the location of the personal medical device. In such embodiments, the medical device module  130  analyzes data derived from anatomic segmentation algorithms, such as thorax or cardiac anatomic segmentation algorithms, to determine and record the location of a personal medical device relative to internal or external fiducial markers, such as the sternum, ribs or clavicle. In other embodiments, the medical device module  130  determines the location of a personal medical device relative to a planned imaging scan range and records the location of the medical device relative to the scan range. In yet further embodiments, the medical device module  130  determines the relative location of a personal medical device by analyzing image data that was previously obtained from the patient during prior imaging procedure(s) and comparing (e.g., image registration techniques) to image data that is acquired from a patient during a current imaging procedure. 
     As mentioned previously, various embodiments of the CT imaging system  100  include a medical device module  130  that is adapted to interface with databases. Such databases may include EMR  210 , HIS  220 , RIS  230 , PACS  240  and medical device manufacturer registries  250  illustrated in  FIG. 2 . The medical device module  130  of these embodiments may poll one or more of these databases to gather information regarding the presence, location and/or additional characteristics of a particular patient&#39;s personal medical device. 
     For example, the medical device module  130  may poll EMR  210  to determine if a patient has a personal medical device and if so gather information regarding the personal medical device. Such information may include for example the type, location, orientation, manufacturer, model, or other characteristics of the device. In a similar manner, the medical device module  130  may also gather similar information from other databases, such as HIS  220  or RIS  230  for example. The medical device module  130  may determine that a patient has a specific device (e.g. a particular model of defibrillator) or may determine that the patient has a device that falls within a general category or series (e.g. a defibrillator, a particular series of defibrillator models, etc.). If it is known or determined that a patient has a particular make and model or category of personal medical device, the medical device module  130  may then poll the device manufacturer database  250 , medical imaging scanner manufacturer database  260 , or regulatory agency databases  270  to gather information regarding that particular device model or category of devices such as operating parameters, radiation sensitivity profiles or other characteristics of the device. 
     In various embodiments, the medical device module  130  collects and analyzes information (i.e. patient data) from multiple sources to classify the personal medical device. For example, in various embodiments the medical device module  130  uses information gathered from image data to classify the personal medical device. For example, the medical device module  130  may use morphologic and attenuation image feature data (including that of multi-energy or spectral features) gathered from a scout scan or full scan. The medical device module  130  may also combine this information with non-image data (e.g., information gathered from EMR  210 , HIS  220 , and/or RIS or other databases) to further classify the personal medical device. For instance, the medical device module  130  may use a neural network, genetic algorithm, support vector machine or other methods in analyzing image data to determine the type of medical device implanted within a patient. Once the medical device module  130  classifies the medical device, this information can be used to reference databases to determine additional characteristics of the medical device. For example, once the medical device module  130  classifies the type, manufacturer and/or model of the personal medical device, the medical device module  130  may poll medical device manufacturer databases  250 , medical imaging scanner manufacturer databases  260  and/or regulatory agency databases  270  to determine the device&#39;s radiation sensitivity profile. Or, for example, the medical device module may determine information about the attenuation properties of a personal medical device for use in attenuation correction. 
     In various embodiments of the CT imaging system  100 , the medical device module  130  provides the clinician or other operator of the CT imaging system  100  with a warning if a personal medical device is detected within a patient prepared to undergo an imaging procedure. The warning provided may be an auditory warning and/or visual warning, or may be some other form of warning. In various embodiments, the medical device module  130  highlights the location of a personal medical device on a reconstructed image (such as a scout scan) by the use of a suitable method. Such methods may provide the operator of the CT imaging system  100  with information regarding the location, orientation, or type of the personal medical device. The medical device module  130  presents this information to the operator of the CT imaging system  100  when desired either visually or in some other fashion, such as a color or shaded overlay (as illustrated for example in  FIG. 4B ). This information may be presented to the CT operator on a scanning console, a gantry display, such as a touch screen display, or in some other fashion. In addition to a warning and/or information regarding the personal medical device, the medical device module  130  may also guide the CT operator through various steps of the imaging procedure. For example, the CT operator may be guided through various steps that are needed in response to the detection of a personal medical device in a patient by prompts presented on a gantry touch screen display. 
     In various embodiments of the CT imaging system  100 , the medical device module  130  may also transmit a notification (e.g., email, page, SMS, phone call, etc.) to a senior technologist, specialist (e.g., cardiologist, neurologist, etc.), radiologist or other medical professional. This notification may be transmitted prior to the commencement of a scanning procedure, during the procedure, or after the procedure. In this manner, such medical personnel may be summoned if additional expertise is required either prior to or after the scanning procedure. For example, the expertise of a cardiologist may be requested prior to the commencement of a particular scanning procedure due to the location of a cardiac rhythm management device within a planned scanned range. 
     Once the medical device module  130  determines that a patient has a personal medical device, and classifies the device, and informs the operator of the presence of the device, the medical device module  130  of various embodiments of the present invention optionally customizes the planned imaging procedures for a particular patient. For example, the medical device module  130  may use information gathered about the type and location of the personal medical device to adjust the radiation dose or radiation dose rate administered over the personal medical device. This can decrease the risk that the primary beam exposure of the medical device exceeds a pre-defined radiation exposure threshold. Such pre-defined radiation exposure thresholds may be established for a particular personal medical device by a manufacturer of personal medical devices, a local hospital policy, a regulatory agency or other institution in combination with patient-specific features (e.g., body habitus, weight). Once the medical device module  130  determines that a patient has a particular type of personal medical device, the medical device module  130  may poll various databases as discussed above to determine the radiation exposure threshold that has been set for that type of device. 
     In addition, the medical device module  130  may automatically adjust or alter additional parameters of a medical imaging procedure or suggest manual adjustments in response to information gathered about a personal medical device. Such parameters include tube voltage, tube current, gantry rotation time, helical pitch, and other parameters. Furthermore, the medical device module  130  may adjust dose modulation parameters such as for example automatic tube current selection, z-axis dose modulation, angular dose modulation, combination z-axis and angular dose modulation, and/or organ-specific dose modulation. The medical device module  130  may also select or deselect wedge or bowtie compensation filters and dynamic end-effect collimation dependent upon the information gathered regarding the personal medical device. In additional embodiments, the medical device module  130  alters or adjusts additional parameters, settings, or characteristics of medical imaging procedures to decrease the risk that the imaging procedure will damage or otherwise interfere with the operation of a personal medical device. In various embodiments, the medical device module  130  may also plan or optimize an entire therapy (e.g., radiation therapy) for a particular patient as opposed to customizing just one medical imaging procedure. 
     In various embodiments of the CT imaging system  100 , the medical device module  130  alters the scan range of a planned imaging procedure based on the type or location of a personal medical device. For example, if the medical device module  130  determines that the patient has an implanted cardiac rhythm management device (ICMRD) or some other personal medical device that is located within or near a planned scan range, the medical device module may alter the scan range so as to avoid interfering with the ICMRD. 
     In addition, the medical device module  130  may propose or suggest one or more alternative scan protocols to the operator that would pose a decreased risk of interfering with the personal medical device if it is determined that a personal medical device is located within or near a planned scan range. If it is determined that a personal medical device is located within a planned scan range and the planned scan range cannot or will not be altered, the medical device module  130  of various embodiments may balance the image quality with the risk of device interference or malfunction. In such instances, the medical device module may alter or customize a variety of parameters of the medical imaging procedure that will result in a decrease of image quality but also result in a decreased risk of interference with the personal medical device. 
     In various embodiments of the CT imaging system  100 , the medical device module  130  moves the couch supporting the patient during imaging to facilitate the placement of optional x-ray shielding, such as a bismuth shield, over the region of the patient&#39;s body having the personal medical device to shield the medical device from radiation exposure. To further facilitate this radiation shielding process, the medical device module  130  may also project lasers onto or otherwise mark the location of the personal medical device to indicate to the operator the region of the patient&#39;s body over which the shield should be located. 
     The medical device module  130  of various embodiments of the CT imaging system  100  optionally monitors the patient&#39;s physiological signals, such as electrocardiography (ECG), electroencephalography (EEG) or other physiological signals, during medical imaging procedures to monitor for potential CT induced irregularities. For example, if the medical device module  130  detects that a patient has an implanted cardiac rhythm management device (ICMRD), the medical device module  130  optionally monitors the patient&#39;s heart activity via ECG to warn the operator if there are any irregularities with the patient&#39;s heart activity during the imaging procedure. In this manner, the imaging procedure may be stopped if the patient&#39;s ICMRD malfunctions or if there are any other irregularities so that the patient can be stabilized and immediate medical attention can be provided. The physiological signals that are monitored by the medical device module  130  can be tailored based on the type of personal medical device that the patient has. For example, different physiological signals may be monitored by the medical device module  130  if the patient has an insulin pump as opposed to a cardiac pacemaker. 
     The medical device module  130  of various embodiments of the CT imaging system  100  is adapted to update various databases, such as EMR  210 , HIS  220  and/or RIS  230 , with information gathered about a particular patient&#39;s personal medical device(s). For example, the medical device module  130  adds or updates information regarding the presence, location, orientation, type, manufacture and model of personal medical device that a patient has to these databases. In addition, the medical device module  130  of various embodiments may add or update information regarding the scan parameters used for a particular medical imaging procedure or the patient&#39;s physiological signals that were measured during the imaging procedure to these databases. Furthermore, the medical device module  130  optionally notifies the appropriate medical professionals, such as the patient&#39;s primary care doctor, cardiologist, neurologist, or other health care workers, that the patient&#39;s medical records have been altered or updated. This may alert them to monitor the patient to determine if there are any potential radiation-induced changes to the device or its behavior. 
     The medical device module  130  of various embodiments of the CT imaging system  100  generates a survey or questionnaire after a medical imaging procedure for the CT technologist or patient to confirm the presence or absence of any CT-induced interactions with a personal medical device. Following the completion of the questionnaire by the CT operator or patient, the medical device module  130  optionally submits the results of the survey along with information regarding the personal medical device and the medical imaging procedure conducted to a hospital quality assurance department, scanner manufacturer, personal medical device manufacturer and/or regulatory agencies. One such regulatory agencies&#39; service is MedWatch, the U.S. Food and Drug Administration&#39;s voluntary safety information and adverse event reporting program. 
     Referring now to  FIG. 3 , an exemplary personal medical device detection and response method  300  according to one aspect of the present invention is illustrated. In step  302 , the CT imaging system  100  is utilized to obtain scout scan or surview image data  306  of the imaged subject  104 . In step  304 , image data  306  from previous imaging procedures of the patient is obtained from the picture archiving and communication system  240  or other source(s). As mentioned previously, image data  306  from either a scout scan or from a previous scanning procedure can be used for the purpose of determining the presence of a personal medical device in accordance with aspects of the present invention. For certain imaging modalities, such as MR, scout scans may not be utilized for various reasons. Accordingly, depending on whether image data from a scout scan or from previous scanning procedures is to be used, only one of step  302  or step  304  may be completed. However, in additional embodiments that employ image data from both a scout scan and from a previous scanning procedure to determine the presence of a personal medical device, both steps  302  and  304  are completed. In yet additional embodiments, no image data is analyzed. Rather, only information obtained from one or more databases (such as EMR  210 , HIS  220 , RIS  230 , PACS  240  and/or device manufacturer registries  250 , etc.) in step  312  is used to determine information about the device. 
     In certain embodiments, image data from an image modality other than the one the patient is being prepared to undergo is used. For example, prior to commencing an MR imaging procedure, a CT scout scan or CT image data from previous CT scans of the patient may be analyzed to help ensure that no non-MR compatible personal medical device enters the magnetic/RF field. 
     In step  308 , the medical device module  130  analyzes the image data  306  for the presence of a personal medical device. As mentioned previously, the medical device module  130  employs the use of mathematical algorithm(s) such as thresholding, connected-component analysis, generalized Hough transform (GHT), model-based segmentation algorithm(s), or other suitable algorithm(s) to analyze the image data  306  for the presence of a personal medical device. If no device is determined to be present, the process  300  stops. If a device is determined to be present, the process  300  continues. 
     In step  310 , the medical device module  130  analyzes image data  306  to determine the location of the personal medical device if any is present. For example, the medical device module  130  analyzes data derived from anatomic segmentation algorithms, such as thorax or cardiac anatomic segmentation algorithms, to determine the location of the personal medical device relative to internal or external fiducial markers of the patient, such as the sternum, ribs or clavicle. 
     In step  312 , the medical device module  130  polls one or more databases, such as electronic medical records (“EMR”)  210 , hospital information systems (“HIS”)  220 , radiology information systems (“RIS”)  230 , picture archiving and communication systems (“PACS”)  240 , personal medical device manufacturer database(s)  250 , medical imaging scanner manufacturer database(s)  260  and/or regulatory agency database(s)  270  or other databases, to gather information about a patient&#39;s personal medical device(s). The medical device module  130  polls these databases to gather information regarding the presence, location, orientation, type, model, manufacturer and/or radiation sensitivity profile or any other relevant characteristics of any personal medical devices a particular patient may have. In certain embodiments of the present invention, the medical device module  130  may poll one or more of these databases. In additional embodiments, the medical device module  130  may not poll any databases, but rather rely solely on image data  306 . 
     The medical device module  130  may be connected to each of these databases in a variety of ways, such as a wired network, wireless network, peer to peer network, client/server network or any other suitable method. Also, the medical device module  130  may not be directly connected to these databases. Rather the contents of these databases could be uploaded to a memory device located within the medical device module  130  itself, the memory  110  of the CT imaging system  100 , or some other memory device that the medical device module  130  is connected to and gathers information from. 
     In step  314 , the medical device module  130  utilizes information gathered from the image data in step  308  and/or from the polling of database(s) in step  312  to classify the personal medical device if any is present. In various embodiments the medical device module  130  uses morphologic and attenuation image feature data (including that of multi-energy or spectral features) or other image data gathered from step  308  and/or non-image data gathered from step  312  to classify the personal medical device. For instance, the medical device module  130  may use a neural network, genetic algorithm, support vector machine or other methods in analyzing image data to determine the type of medical device implanted within a patient. This information is then combined with information gathered from the polled databases such as device type, manufacturer, model, radiation sensitivity profile and other characteristics of the medical device. 
     The steps  312  and  314  may be performed iteratively in series to reconcile information obtained from different sources. In various embodiments of the CT imaging system  100 , the medical device module  130  may poll multiple databases in step  312  either simultaneously or in series. Also, the medical device module  130  may gather information from a database or databases in step  312  to gather certain information and then re-poll these same database(s) or additional database(s) to gather additional information. For example, the medical device module  130  may determine the type, manufacturer and model of personal medical device based on the polling of one database, such as the hospital information systems database  220 . That information may then be used for example to poll another database, such as a device manufacturer database  250 , to determine additional information such as the radiation sensitivity profile of the personal medical device. 
     If a personal medical device is detected by the medical device module  130 , the medical device module  130  notifies the CT operator of the presence of the personal medical device by an auditory and/or visual warning in step  316 . For example, the medical device module  130  may give an audible beep or other warning to alert the CT operator that a personal medical device is present and certain actions may be required of the CT operator. 
     There may be a discrepancy regarding the presence of a personal medical device between the information gathered from the databases in step  312  and the determination made by the medical device module  130  based on image data in step  308 . In that event, the medical device module  130  will indicate to the CT operator that additional investigation is required in step  318 . For example, the medical device module  130  may have determined that a personal medical device is present based on the analysis of the image data  306  at step  308 , while no record of such a personal medical device has been detected from the polled databases at step  312 . Likewise, the polled databases at step  312  could include information regarding the presence of a personal medical device that is no longer present or is not detected in the image data  306  by the medical device module  130 . 
     Similarly, discrepancies regarding the presence of a personal medical device could also arise if image data is used from both a scout scan and from previous imaging procedures of the patient. For example, the patient may have had a personal medical device at the time of the previous imaging procedure that was thereafter removed or changed. In such instances, the CT operator or other medical technician will carry out a manual personal medical device detection procedure in response to the prompt of step  318  to determine whether the patient has a personal medical device. These procedures may include a visual check, inquiry of the patient, palpation of relevant patient regions, or other inquiries. Subsequent to this manual investigative procedure, the CT operator may input information into the medical device module  130  to resolve the discrepancy regarding the presence of a personal medical device. 
     In step  320 , the medical device module  130  highlights the location of the personal medical device on a reconstructed image (such as a scout scan). For example, a color or shaded overlay may be used. In this way, the operator of the CT imaging system  100  is provided with information regarding the location of the personal medical device. In various embodiments, the medical device module  130  also visually depicts the location of the personal medical device relative to a planned imaging scan range for the operator of the CT imaging system  100  via the display  140  or some other display device when desired. 
       FIG. 4A  illustrates an exemplary reconstructed CT scout scan image  400  generated by a software program. The image  400  includes an implanted cardiac rhythm management device (ICMRD)  410 . It also illustrates a planned scanned range  420  that includes the ICMRD  410 . Referring now to  FIG. 4B , an exemplary reconstructed CT scout scan image  400 ′ generated by a software program according to one aspect of the present invention is illustrated. The image  400 ′ was generated based on the same data used to generate the image  400 . In the scout scan image  400 ′ of  FIG. 4B , however, the implanted cardiac rhythm management device  410  has been detected and highlighted in relation to a planned scan range  430 . 
     In step  322 , the medical device module  130  customizes the medical imaging procedure in response to the detection of a personal medical device. As described previously, the medical device module  130  may use information gathered about the type, location and/or orientation of the personal medical device to adjust the radiation dose or radiation dose rate that is to be administered over the personal medical device. In addition, the medical device module  130  may adjust tube voltage, tube current, gantry rotation time, helical pitch, or other parameters of the planned scanning procedure. Furthermore, the medical device module  130  may adjust dose modulation parameters (e.g., automatic tube current selection, z-axis dose modulation, angular dose modulation, combination z-axis and angular dose modulation, and/or organ specific dose modulation). The medical device module  130  may also select or deselect wedge or bowtie compensation filters or dynamic end-effect collimation dependent upon the information gathered regarding the personal medical device. In additional embodiments, the medical device module  130  alters or adjusts additional parameters, settings, or characteristics of medical imaging procedures to decrease the risk that the imaging procedure will damage or otherwise interfere with the operation of a personal medical device. 
     In various embodiments of the CT imaging system  100 , the medical device module  130  alters the scan range of a planned imaging procedure based on the type, location and/or orientation of a personal medical device. Referring again to  FIG. 4B , the planned scan range  430  has been altered in comparison to the planned scan range  420  of  FIG. 4A . The scan range  430  has been altered to avoid scanning over the implanted cardiac rhythm management device  410 . In addition, the medical device module  130  may propose or suggest one or more alternative scan protocols to the operator that would pose a decreased risk of interfering with the personal medical device if it is determined that a personal medical device is located within or near a planned scan range. 
     Also, as described previously, in various embodiments of the CT imaging system  100 , the medical device module  130  moves the couch supporting the patient during imaging to facilitate the placement of optional x-ray shielding, such as a bismuth shield, over the region of the patient&#39;s body having the personal medical device to shield the medical device from radiation exposure. To further facilitate this radiation shielding process, the medical device module  130  may also project lasers onto or otherwise mark the location of the personal medical device to indicate to the operator the region of the patient&#39;s body over which the shield should be located. 
     In step  324 , the medical device module  130  monitors a patient&#39;s physiological signals during a medical imaging procedure, such as electrocardiography (ECG), electroencephalography (EEG) or other physiological signals, to monitor for potential CT induced irregularities. In this manner, the imaging procedure may be stopped if there are any irregularities so that the patient can be stabilized and immediate medical attention can be provided. The physiological signals that are monitored by the medical device module  130  can be tailored based on the type of personal medical device that the patient has. In step  326 , the medical device module  130  warns the CT operator and/or stops the medical imaging process if any dangerous irregularities occur with the patient&#39;s physiological signals. 
     In step  328 , the medical device module updates various databases, such as electronic medical records (“EMR”)  210 , hospital information systems (“HIS”)  220 , radiology information systems (“RIS”)  230 , with information gathered about a particular patient&#39;s personal medical device(s). For example, the medical device module  130  adds or updates information regarding the presence, location, type, orientation, manufacture, model of personal medical device that a patient has to these databases. In addition, the medical device module  130  of various embodiments adds or updates information regarding the scan parameters used for a particular medical imaging procedure or the patient&#39;s physiological signals that were measured during the imaging procedure to these databases as well. Furthermore, in step  328 , the medical device module  130  optionally notifies the appropriate medical professionals that the patient&#39;s medical records have been altered or updated and alerts them to monitor the patient to determine if there are any potential radiation-induced changes to the device or its behavior. 
     In step  330 , the medical device module  130  generates a survey or questionnaire for the CT operator. The purpose of this survey is to confirm the presence or absence of any CT-induced interactions with a personal medical device. Following the completion of the questionnaire by the CT operator, the medical device module  130  optionally submits the results of the survey along with information regarding the personal medical device and the medical imaging procedure conducted to a hospital quality assurance department, scanner manufacturer, personal medical device manufacturer and/or regulatory agency. 
     Various embodiments of the present invention may include the previously discussed method steps in a variety of orders. For example, in various embodiments, one or more database(s) may be polled prior to the analysis of image data  306 . For instance, a patient may be registered on a CT imaging system for an imaging procedure. Once the patient has been registered, the medical device module  130  may then poll one or more databases (such as EMR  210 , HIS  220 , RIS  230 , PACS  240  and/or personal medical device manufacturer database(s)  250 ) to determine if a patient has a personal medical device. If the polling of these database(s) indicates the history of a personal medical device, a notification regarding the presence of the device and any other known information about the device may be communicated to the CT operator. If image data  306  of the patient (such as scout scan or image data from a previous imaging procedure) is available, the image data  306  may then be analyzed for the presence of a personal medical device. If no image data  306  of the patient is available, a scout scan of the patient may be conducted. Alternatively, in certain embodiments, no image data  306  is analyzed and only information obtained from the polling of one or more database(s) is used. 
     In addition, various embodiments may include either more or less steps than those previously described. For example, one embodiment of the present invention may identify the presence and location of a personal medical device but not alter the planned medical imaging procedure in response to the detection of the personal medical device. 
     The present invention may be implemented in a variety of ways. The medical device module  130  may be provided as a component of a medical imaging device, such as a CT scanner. The medical device module  130  may also be provided on a workstation linked to a medical imaging device, as a component of a network storage device, or of an imaging archiving database, such as PACS, or as an application within a host software. The medical device module  130  may also be implemented on and/or connected to a medical imaging device via a software application, web service, and/or application service provider (ASP) model via standard image/data transfer protocols and standards (e.g., DICOM, HL7, HTTP, SOAP, XML). As described previously, this invention is applicable to a variety of imaging modalities, such as PET, SPECT, CT, MR, ultrasound, x-ray, fluoroscopy, or other image modalities or a system combining one or more of these image modalities. The medical device module  130  may comprise multiple parts or components that are each located in different locations. 
     The aforementioned functions, such as for example, analyzing image data to determine the presence of a personal medical device, analyzing image data to determine the location of a personal medical device, classifying a personal medical device based upon image data and information gathered from the polling of database(s), customizing, altering, initiating and/or terminating scans, selecting desired scan or reconstruction protocols, manipulating the volumetric data, and the like, can be performed as software logic. “Logic,” as used herein, includes but is not limited to hardware, firmware, software and/or combinations of each to perform a function(s) or an action(s), and/or to cause a function or action from another component. For example, based on a desired application or needs, logic may include a software controlled microprocessor, discrete logic such as an application specific integrated circuit (ASIC), or other programmed logic device. Logic may also be fully embodied as software. 
     “Software,” as used herein, includes but is not limited to one or more computer readable and/or executable instructions that cause a computer or other electronic device to perform functions, actions, and/or behave in a desired manner. The instructions may be embodied in various forms such as routines, algorithms, modules or programs including separate applications or code from dynamically linked libraries. Software may also be implemented in various forms such as a stand-alone program, a function call, a servlet, an applet, instructions stored in a memory, part of an operating system or other type of executable instructions. It will be appreciated by one of ordinary skill in the art that the form of software is dependent on, for example, requirements of a desired application, the environment it runs on, and/or the desires of a designer/programmer or the like. 
     The systems and methods described herein can be implemented on a variety of platforms including, for example, networked control systems and stand-alone control systems. Additionally, the logic, databases or tables shown and described herein preferably reside in or on a computer readable medium, such as a component of the imaging system  100  like the memory  110  or the image processor  120 . Examples of different computer readable media include Flash Memory, Read-Only Memory (ROM), Random-Access Memory (RAM), programmable read-only memory (PROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk or tape, optically readable mediums including CD-ROM and DVD-ROM, and others. Still further, the processes and logic described herein can be merged into one large process flow or divided into many sub-process flows. The order in which the process flows herein have been described is not critical and can be rearranged while still accomplishing the same results. Indeed, the process flows described herein may be rearranged, consolidated, and/or re-organized in their implementation as warranted or desired. 
     The invention has been described with reference to the preferred embodiments. Modifications and alterations may occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be constructed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.