JP2005058526A - Method and device for photographing tomographic image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the irradiation volume of X-rays, a magnetic field, ultrasonic waves and light, or the like, to irradiate an object therewith, to shorten photographing time and to suppress the exposure of the object in the photographing of tomographic images. <P>SOLUTION: A region R under consideration is extracted from an image obtained by photographing the object, a standard point P1 is set in the image, and the position of the region R under consideration is stored as relative position information from the standard point P1. Before photographing the tomographic image of the object, a reference point P2 corresponding to the standard point P1 in the object is recognized, a detailed photographing region Rd to photograph the tomographic image of the object in details corresponding to the region R under consideration in a medical image obtained by the relative position information is obtained with the reference point P2 of the object as a reference, and the detailed photographing region Rd is photographed in details. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tomographic image capturing method and apparatus for capturing a tomographic image so as to reduce a burden on a subject, and a program therefor.

  In CT (Computerized Tomography) and MRI (Magnetic Resonance Imaging), a patient (subject) is scanned at a predetermined scan pitch (slice thickness) to obtain a plurality of tomographic images, and a lesion is detected. It is discovered and the state of the lesion is observed to diagnose the presence of disease and the progress. Such a plurality of tomographic images have more information about the subject than a conventional two-dimensional radiographic image, and therefore a highly accurate diagnosis is possible. For this reason, once a two-dimensional radiographic image is taken, a tomographic image of a portion that appears to be a lesion found in the two-dimensional radiographic image is further taken using CT or MRI, and the state of the tissue and the internal structure are examined. Diagnosis is made by observing in detail.

  However, since many tomographic images are taken in CT or MRI, the amount of X-ray or magnetic field applied to the subject increases, and the subject is significantly exposed. Also, it takes a long time to shoot many tomographic images, which is very burdensome for the subject.

  Therefore, a technique called Auto mA that automatically calculates the tube current value given to the X-ray tube for determining the X-ray dose according to the scan position of the subject is known so that imaging can be performed with as little exposure as possible. It has been. The amount of X-ray attenuation varies depending on the body shape and part of the subject. For example, the lungs occupy most of the chest, so the amount of X-ray attenuation is small. The amount gets bigger. Therefore, a good tomographic image may not always be obtained depending on the part to be imaged and the body shape of the subject even if the image is taken with the same X-ray dose. In order to suppress the exposure dose of the subject, it is better to reduce the X-ray dose as much as possible. However, the same X-ray dose as the X-ray dose given to the site where the X-ray attenuation is small is applied to the site where the X-ray attenuation is large. If it is applied, a good tomographic image cannot be obtained. However, if the same X-ray dose as the X-ray dose given to the site where the X-ray attenuation is large is given to the site where the X-ray attenuation is small, the exposure is more than necessary. The In Auto mA, an appropriate X-ray dose is calculated according to the part of the subject with different amounts of X-ray attenuation. Therefore, if the calculation result of Auto mA is used, the X-ray attenuation depends on the part of the subject with different X-ray attenuation. An appropriate X-ray dose can be set.

  However, when the tube current value calculated by Auto mA is observed for each part, it may not always include an appropriate value. In addition, when tomographic imaging is performed by CT, MRI, etc., a plan (scan plan) is established for the scan conditions and image reconstruction processing conditions in accordance with the diagnostic site and purpose, and the operator who operates the system. However, photographing is performed by inputting photographing conditions according to the plan from the operation console. Therefore, a graph representing the relationship between the tube current value that controls the X-ray dose of the X-ray tube calculated by the Auto mA function and each scan position is superimposed on the subject fluoroscopic image (scout image) and displayed. In some cases, the tube current value can be adjusted by dragging the mouse with a mouse or the like, and the exposure dose is reduced as much as possible while photographing each part with an appropriate X-ray dose (for example, Patent Document 1). .

Also, before taking a tomographic image by scanning the region of interest at a predetermined scan pitch, two images of an axial image and a sagittal image are taken, and the axial image is first displayed on the display device and encoded to the operator. By specifying the shooting area in the direction and the lead direction, and further displaying the sagittal image and specifying the shooting area in the slice direction (number of slices, etc.), and taking the specified number of axial images In some cases, it is possible to reduce the exposure amount and further reduce the imaging time by not imaging the extra part while reliably imaging the range to be imaged (for example, Patent Document 2).
JP 2002-177261 A JP-A-5-269113

  When a two-dimensional radiographic image shows a shadow that seems to be a lesion, a tomographic image of the shadow is taken in order to observe the shadow in detail, but the dose of X-rays or magnetic field is reduced as much as possible. Therefore, it is desirable to reduce the shooting time for shooting.

  However, in the method of Patent Document 1, it is possible to perform imaging with the smallest X-ray dose among the X-ray doses capable of obtaining a good tomographic image. However, the method is detailed only for a portion that needs to be observed in detail, such as a shadow portion. You can't shoot for information.

  On the other hand, in the method of Patent Document 2, it is possible to specify a region for capturing a tomographic image from an axial image and a sagittal image displayed on the display screen. In particular, the imaging area of the tomographic image is not determined. In addition, the range and imaging conditions for capturing a tomographic image depend on the experience of the observer and the level of image interpretation ability, and the area required for imaging is not always accurately specified.

  Therefore, in view of the above circumstances, the present invention suppresses the exposure amount of a subject or shortens the imaging time when imaging a tomographic image of a part that needs to be observed in detail so that detailed information can be obtained. It is an object of the present invention to provide a tomographic imaging method and apparatus capable of performing the same and a program therefor.

The tomographic imaging method of the present invention includes a first step of extracting a region of interest from a medical image obtained by imaging a subject,
A second step of obtaining a detailed photographing region for photographing the tomographic image of the subject corresponding to the region of interest in detail before photographing the tomographic image of the subject;
And a third step of controlling tomographic image photographing means for photographing the subject so as to photograph the detailed photographing region in detail.

  “Medical images” include two-dimensional images taken with CR (Computed Radiography) or the like, and tomographic images taken with CT, MRI, US (ultrasonography), optical CT, or the like.

  The “attention area” is an area where it is determined that it is necessary to take a tomographic image, such as a shadow appearing on a medical image. The shadow includes tumors and tumors observed in various parts such as the head and chest. In addition, it includes a shadow showing various symptoms such as cancer, and a shadow where it is not clear whether or not it is a shadow showing various symptoms such as tumor, tumor, and cancer. Also, the “region of interest extraction” is, for example, computer aided diagnosis (CAD), and a candidate region of an abnormal shadow that is not normally observed such as a tumor, tumor, or cancer is extracted from a medical image as a region of interest. .

  Further, the “tomographic image” includes images taken by CT, MRI, US, optical CT, and the like.

  “Detailed imaging” refers to imaging of tomographic images so that detailed information can be obtained from other imaging regions. For example, imaging of tomographic images with a reduced scan pitch or irradiation of X-rays or the like The amount is taken so as to obtain a clear tomographic image.

The second step is
A reference point setting step for setting a reference point in the medical image;
A relative position information storing step for storing the position of the region of interest as relative position information from the reference point;
A reference point recognition step for recognizing a reference point corresponding to the reference point in the subject before capturing a tomographic image of the subject;
The detailed photographing area may be obtained based on the relative position information with the reference point of the subject as a reference.

  The “reference point” is a point on the medical image that serves as a reference for measuring the position of the region of interest, and is set to, for example, the clavicle, the intercostal space, the side, the pigtail, etc., which are characteristic locations of the subject.

  The “reference point” is a point corresponding to the reference point of the medical image, and is a point that serves as a reference for calculating a region of interest on the subject from which the tomographic image is taken. For example, when a reference point is set at the position of the clavicle in the medical image, the position of the clavicle of the subject lying on the imaging stand is recognized as a reference point in order to take a tomographic image. Specifically, the position of the reference point is recognized by detecting the distance from the head of the subject lying on the imaging stand and the affected part measurement marker such as a metal piece attached to the subject.

Further, the reference point setting step is to set a reference point by detecting the marker imaged in the medical image by attaching a marker to a position as the reference point of the subject.
In the reference point recognition step, the marker attached to the subject may be recognized and used as the reference point before capturing the tomographic image.

  As the “marker”, a marker that is photographed with a contrast different from that of a human tissue when photographing with CR, CT, MRI, or the like can be used. For example, a piece of metal such as lead or a small container containing a marker material can be raised.

  In addition, the sixth step may perform detailed imaging by controlling the scan pitch of the detailed imaging area to be small.

  In addition, the sixth step may perform detailed imaging by controlling the amount of irradiation in the detailed imaging area to be increased.

Further, the tomographic imaging apparatus of the present invention comprises an extraction means for extracting a region of interest from a medical image obtained by photographing a subject,
Detailed imaging region acquisition means for obtaining a detailed imaging region for performing detailed imaging of a tomographic image of the subject corresponding to the region of interest;
The tomographic image photographing means for photographing the subject includes photographing instruction means for instructing photographing so that the detailed photographing area obtained by the detailed photographing area acquisition means is photographed in detail.

  “Imaging instruction” means giving an instruction of imaging conditions such as an imaging range, a scan pitch, and an X-ray dose to a tomographic imaging apparatus such as CT, MRI, US, and optical CT. In this case, the imaging range and imaging conditions are instructed to control the imaging unit, and information such as the imaging range and imaging conditions is transmitted from a computer such as a CAD apparatus to the tomographic imaging apparatus and instructed.

  According to the tomographic imaging method and apparatus of the present invention, a shadow or the like that appears in a two-dimensional radiographic image obtained by imaging a subject with CR is extracted as a region of interest by CAD or the like, and a tomography such as CT or MRI is extracted. When taking a tomographic image with an image taking device, the image is taken by reducing the scan pitch or increasing the dose of X-rays or magnetic field so that detailed information can be obtained only in the region corresponding to the region of interest. Therefore, it is possible to suppress the total exposure amount of the subject. In addition, when the scan pitch is reduced so that detailed information can be obtained only in the region corresponding to the region of interest, the photographing time can be shortened.

  In addition, reference points corresponding to the reference points on the subject are set before taking tomographic images of the subject by setting reference points in the clavicle, intercostal space, side, pigeon tail, etc. that are characteristic locations of the subject in the medical image. Is recognized and the detailed imaging region is obtained, the position of the medical image (for example, a two-dimensional radiographic image obtained by imaging with a CR or the like), the position of the subject for tomographic imaging, and the position on the medical image Can be accurately aligned.

  In addition, when shooting is performed with a marker attached to the subject, more accurate positioning is possible by aligning the position of the marker on the medical image and the position of the marker of the subject that captures the tomographic image. become.

  Further, if the tomographic image is taken with the scan pitch of the detailed imaging region reduced, it becomes possible to observe the state of the internal tissue such as the shadow portion in detail.

  Alternatively, if the tomographic image is taken by increasing the amount of irradiation in the detailed photographing region, the inside of the shadow portion can be clearly photographed.

  Embodiments of the present invention will be described below. First, a tomographic imaging system will be described.

  As shown in FIG. 1, the tomographic imaging system 1 includes a computer aided diagnosis (CAD) apparatus 2, an imaging apparatus (tomographic imaging means) 3 such as an MRI apparatus, and an image storage server 4 that stores medical images. Are connected by a network 5.

  The image storage server 4 stores subject information such as a patient ID, name, sex, date of birth, etc. attached to a two-dimensional medical image obtained by photographing a patient (subject) with a CR device or the like.

  The CAD device 2 includes an extraction unit 21 that extracts, from the medical images stored in the image storage server 4, for example, candidate areas of abnormal shadows that are not normally observed, such as tumors, tumors, and cancers, as attention areas. Further, a reference point setting means 22 for detecting a part having a characteristic of the human body from the medical image (for example, clavicle, intercostal space, armpit, pigeon tail in the chest image) and setting the reference point, and the position of the extracted attention area Is obtained as a relative position from the reference point, and a relative position information storage means 23 for storing the relative position and the medical image in association with each other in the image storage server 4 (storage means) is provided.

  The imaging device 3 captures a tomographic image based on the subject information, a medical image of the subject to be imaged, a region of interest in the medical image, a reading unit 31 that reads a relative position from a reference point of the region, and an image storage server 4. The reference point recognition means 32 for recognizing the reference point corresponding to the reference point in the subject before the image is taken, and the photographing region of the subject corresponding to the attention region in the medical image based on the relative position information as the reference photographing point. The detailed imaging region acquisition means 33 to be obtained and the region corresponding to the target region of the subject are set as the detailed imaging region, and for example, detailed information can be obtained by reducing the scan pitch or increasing the X-ray dose or magnetic field to be irradiated. An imaging instruction unit 34 that instructs the imaging unit 35 to perform detailed imaging is provided.

  Here, a procedure in the case of taking a tomographic image of a patient with the tomographic imaging system 1 of the present embodiment will be described based on the flowchart of FIG. In this embodiment, a case where the chest is photographed will be described.

  First, a medical image of a subject is taken with a CR device or the like (S100). The captured medical image is stored in the image storage server 4 with subject information such as patient ID, name, sex, date of birth, and the like (S101).

  The CAD device 2 reads a medical image from the image storage server 4 and extracts a candidate region of an abnormal shadow that is not normally observed, such as a cancerous portion by the extraction unit 21 (S102). There are various methods for extracting such candidate regions, and the following can be given as specific methods.

  For example, an abnormal shadow such as a tumor photographed in a medical image photographed by a CR device or the like has a generally rounded outline and is observed as a region having a larger pixel value than the surroundings on the image. Such an abnormal shadow is a region having a shape in which the same density spreads concentrically, and a density value gradient is observed such that the density value decreases as the density value distribution goes from the peripheral part to the center part. The gradient lines are concentrated toward the center direction of the abnormal shadow region, and the gradient of the density value is calculated as a gradient vector, and a candidate region for the abnormal shadow is detected from the degree of concentration of the gradient vector. An abnormal shadow candidate region extracted by evaluating such a degree of concentration is set as a region of interest. Typical examples of evaluating the concentration degree of the gradient vector include an iris filter and an adaptive ring filter (for details, see, for example, Japanese Patent Laid-Open No. 8-294479).

  Further, an abnormal shadow candidate region is extracted using a filter such as an iris filter, a histogram of the density of pixel values appearing inside the extracted abnormal shadow candidate region is obtained, and a plurality of feature amounts based on this histogram, For example, a variance value, a contrast, an angular moment, etc. are calculated, and it is further determined whether or not the candidate region is a tumor shadow based on an evaluation function value in which each feature amount is defined by a predetermined weighting function (for details, see FIG. (For example, see JP-A-9-167238). In this case, the extracted region may be set as the attention region only when the extracted region is highly likely to be a tumor shadow. Alternatively, it is possible to determine whether the extracted shadow is a malignant tumor shadow from the flatness of the extracted shadow, the ambiguity around the area, the collapse of the area, and so on. The shooting conditions may be determined as the attention area to be used.

  Further, the CAD device 2 sets a characteristic position of the subject photographed in the medical image by the reference point setting unit 22 as a reference point (S103). For example, in the case of a medical image obtained by photographing the chest, the position of the clavicle is detected, and a reference point is set at this position. As a specific example of the method for setting the reference point, a cardiothoracic image is prepared on a medical image by preparing a template that is similar in shape to the contour of the reference average cardiothoracic rib (an area combining the rib cage and the heart). The contour of the cardiothoracic cage is detected by performing the template matching process with the contour of the above (for details, refer to Japanese Patent Application Laid-Open No. 2002-109550 of the present applicant), and the approximate position of the clavicle is obtained from the detected contour of the cardiothoracic cage, A reference point P1 can be set at this point (see FIG. 3). Alternatively, a medical image may be displayed on a display device, and an operator may visually recognize the displayed chest image and specify the reference point P1 with a pointing device such as a mouse.

  Therefore, the relative position information storage means 23 obtains the position of the attention area R as a relative position from the reference point, and stores the relative position information in the image storage server 4 in association with the medical image. For example, in FIG. 3, the relative position (d1, d2) in the body axis direction A is determined from the reference point in the range of the attention area R, and this is stored as relative position information (S104).

  When a medical image obtained by photographing a patient (subject) with a CR device or the like has a shadow (region of interest) suspected of being a lesion, the subject is captured using tomographic image photographing means 3 such as CT. The part corresponding to the attention area is taken. Hereinafter, a case where the tomographic image capturing unit 3 is used as a CT apparatus and a tomographic image of a part corresponding to a region of interest is captured will be described.

  First, as shown in FIG. 4, the reference point recognition unit 32 measures the distance D (for example, the distance along the body axis direction A) from the top of the subject lying on the imaging table S of the CT apparatus to the clavicle, The position is stored and recognized as a reference point P2 (S105). For example, a measuring device for measuring the distance from the top of the subject's head is provided in the CT apparatus, and the distance from the top of the head to the position of the clavicle is automatically measured. Alternatively, the operator who operates the CT apparatus can measure the distance D from the position of the top of the head to the position of the clavicle and input it from the operation console.

  Therefore, the reading unit 31 reads the relative position information of the medical image of the subject and the region of interest from the image storage server 4 based on the patient ID of the subject for which the tomographic image is captured, and the detailed imaging region acquisition unit 33 compares the relative position information with the reference point. The attention area R on the subject imaged by the CT apparatus is obtained as the detailed imaging area Rd from the position information (S106). More specifically, the detailed position Rd is calculated by adding the relative position (d1, d2) to the reference point P2. In addition, since a lesioned part such as cancer may be larger than the attention area R photographed in the medical image, an area corresponding to the attention area R on the subject lying on the photographing table S as shown in FIG. A region obtained by adding α to the front and rear may be obtained as the detailed imaging region Rd.

  Here, the operator inputs imaging conditions (scanning conditions) such as the scan pitch and X-ray dose of the detailed imaging region Rd from the operation console according to the site to be imaged and the medical condition (S107). The imaging conditions of the detailed imaging area Rd are changed from the other imaging areas of the subject and the imaging conditions are changed. For example, only the detailed imaging area Rd is set to have a small scan pitch or the X-ray dose is increased. Set to take an image. The imaging instruction means 34 instructs and controls the imaging unit 35 to perform imaging under the set imaging conditions, and only the detailed imaging region Rd is imaged with a reduced scan pitch, or the X-ray dose is increased. Take a picture. Alternatively, only the detailed imaging region Rd may be imaged and other regions may not be imaged (S108).

  Further, after the tomographic image is captured, display is performed so that the correspondence between the result of analyzing the medical image by the CAD device 2 and the detailed imaging region Rd in which the tomographic image is captured can be understood.

  For example, as shown in FIG. 5, a display in which a subject fluoroscopic image (a scout image) is displayed and a display in which a medical image is displayed and a region of interest R extracted by the CAD device 2 is displayed on the medical image are displayed side by side. To do. At this time, the reference point P2 when the tomographic image is captured and the reference point P1 when the medical image is captured are displayed so as to correspond to each other, and the detailed imaging region Rd is also displayed. FIG. 5 shows an example in which the detailed photographing area Rd is pointed by a black arrow, but the detailed photographing area Rd may be displayed in a different color. Further, the tomographic images are displayed in a stack, and displayed so that the displayed tomographic images correspond to positions on the scout image (white arrows in the example of FIG. 5). By displaying in this way, the correspondence between the position of the attention area R extracted from the medical image and the position of the tomographic image is attached, so that it is possible to determine whether or not the shadow extracted as the attention area R is an abnormal shadow. In the case of an abnormal shadow, it becomes easy to determine a medical condition.

  The case where the reference point P1 is set to a characteristic location such as the clavicle of the subject with the CAD device 4 and the corresponding reference point P2 is measured and matched with the CT device or the like has been described above. For example, imaging may be performed with markers that are photographed at a contrast different from that of human tissue on the collarbone, between the ribs, the sides, the pigeon tail, and the like. For example, for a marker, a metal piece such as lead or a marker material (for example, liquid such as water or oil) is put in a minute container, and the container is attached to a characteristic place of a subject (specific marker). For materials, see, for example, JP-T-8-5056744), and the subject is imaged by X-ray imaging and CT imaging. Since the marker is photographed with different contrasts of human tissues, the position can be extracted from the photographed image as a reference point.

  Therefore, the reference point setting unit 22 detects the position of the marker from the medical image of the subject to which the marker is attached, and sets the reference point P1. Also, a marker is attached at the same position as when a medical image is taken on the subject, and a tomographic image is taken with a CT apparatus. In the CT apparatus, for example, the position of the marker is detected by pre-scanning, and the point is referred to The point recognition unit 32 may recognize the reference point P2.

  Alternatively, before capturing a tomographic image of the detailed imaging region Rd, a scout image created by pre-scanning the subject is displayed, and the reference point P2 is displayed on the scout image, and the reference point P2 and the reference point are displayed. A medical image may be displayed so that P1 corresponds, so that it can be confirmed whether or not the position of the reference point P1 and the position of the reference point P2 match. At this time, if it is confirmed that the position of the reference point P1 and the position of the reference point P2 are shifted on the displayed screen, the position of the reference point P2 is indicated by a pointing device such as a mouse. You may make it adjust. By taking a tomographic image of the detailed imaging region Rd after making the adjustment in this way, it is possible to perform imaging accurately.

  The case where the tomographic imaging means is CT has been described above, but the same can be done with apparatuses such as MRI, US, and optical CT. In addition, it is desirable that the affected area is diagnosed from a plurality of modalities such as CT, MRI, US, optical CT, etc., but if imaging is performed using a plurality of modalities, X-rays and magnetic fields And so on, and also the shooting time, which is very burdensome for the subject. Therefore, as described above, the position (relative position from the reference point) of the attention area R extracted from the image storage server 4 by the CAD device is read for each modality, and the detailed photographing area Rd for performing detailed photographing is obtained and photographing is performed. By doing so, it is possible to capture in detail only the same part with a plurality of modalities, so that the exposure dose can be suppressed and the imaging time can be shortened, thereby reducing the burden on the subject.

  In the above description, the medical image has been described as a two-dimensional medical image taken with a CR. However, a tomographic image taken with a coarse scan pitch using CT, MRI, US, optical CT, or the like is used as a medical image, and a region of interest is obtained from the tomographic image. R is extracted and the region of interest R is set as the detailed imaging region Rd, and the imaging is performed again by reducing the scan pitch of the region, or detailed imaging is performed by increasing the irradiation amount of X-ray dose, magnetic field, ultrasonic wave, etc. May be.

  As described above, the case where the reference point corresponding to the reference point is recognized and the detailed imaging region corresponding to the attention region is obtained has been described. For example, the medical image is a tomographic image captured with a coarse scan pitch, and the medical image is obtained. If the region of interest extracted from the above is taken again in detail with the same modality, the location of the region of interest and the location of the detailed imaging region match even without setting the reference point or recognizing the reference point. The detailed shooting may be performed by changing the shooting conditions with the position of the detailed shooting area as the position.

  Further, in the above description, a case has been described in which the detailed photographing area is obtained by the photographing device and the photographing condition of the detailed photographing region is changed. However, the detailed photographing region acquiring unit is provided with the detailed photographing region acquisition unit and the photographing instruction unit on the CAD device side. The relative position value may be obtained from the reference point at which the position of the detailed photographing area is recognized by the photographing apparatus, and the relative position obtained by the photographing instruction means and the photographing condition may be transmitted to the photographing apparatus. When the imaging apparatus recognizes a reference point of a subject such as a marker in accordance with the transmitted imaging instruction, it may be configured to take an image of a region at a relative position from the reference point under the specified imaging condition.

  Further, the CAD device is not limited to a single computer, but may be composed of a plurality of computers, and each function of the CAD device may be distributed.

  In each of the above-described embodiments, the case where a medical image is stored in an image storage server and read is described. However, the medical image may be read from a portable recording medium such as a DVD or a CD-ROM. Alternatively, medical images may be directly read from CAD via a network such as a LAN.

  As described above in detail, it is possible to shorten the imaging time by imaging only the region of interest extracted by the CAD device while reducing the scan pitch. In addition, the exposure amount of the subject can be suppressed by photographing only the attention area while increasing the irradiation amount of the X-ray dose, the magnetic field, and the ultrasonic wave.

  In addition, since the imaging time can be shortened, it is possible to accurately determine the affected part by capturing tomographic images of a plurality of modalities without imposing a burden on the patient as a subject.

Configuration diagram of tomographic imaging system Flowchart diagram for explaining the procedure for taking a tomographic image The figure showing an example of the medical image which imaged the chest Diagram for explaining setting of reference point The figure showing an example of the screen which displayed the photography result

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tomographic imaging system 2 Computer diagnostic assistance (CAD) apparatus 3 Tomographic imaging means 4 Image storage server 5 Network 21 Extraction means 22 Reference point setting means 23 Relative position information storage means 31 Reading means 32 Reference point recognition means 33 Detailed imaging area Acquisition means 34 Imaging instruction means P1 Reference point P2 Reference point R Area of interest Rd Detailed imaging area

Claims (6)

A first step of extracting a region of interest from a medical image obtained by photographing a subject;
A second step of obtaining a detailed photographing region for photographing the tomographic image of the subject corresponding to the region of interest in detail before photographing the tomographic image of the subject;
A tomographic imaging method comprising: a third step of controlling tomographic imaging means for imaging the subject so as to perform detailed imaging of the detailed imaging region. The second step comprises:
A reference point setting step for setting a reference point in the medical image;
A relative position information storing step for storing the position of the region of interest as relative position information from the reference point;
A reference point recognition step for recognizing a reference point corresponding to the reference point in the subject before capturing a tomographic image of the subject;
The tomographic imaging method according to claim 1, wherein the detailed imaging region is obtained based on the relative position information with the reference point of the subject as a reference. The reference point setting step is to set a reference point by detecting the marker imaged in the medical image by attaching a marker to a position to be a reference point of the subject;
3. The tomographic image capturing method according to claim 2, wherein the reference point recognizing step recognizes the marker attached to the subject and sets the reference point before capturing the tomographic image.   The tomographic image photographing method according to any one of claims 1 to 3, wherein in the third step, detailed photographing is performed by controlling so as to reduce a scan pitch of the detailed photographing region.   The tomographic image photographing method according to any one of claims 1 to 3, wherein in the third step, detailed photographing is performed by controlling the amount of irradiation in the detailed photographing region to be increased. Extraction means for extracting a region of interest from a medical image obtained by photographing a subject;
Detailed imaging region acquisition means for obtaining a detailed imaging region for performing detailed imaging of a tomographic image of the subject corresponding to the region of interest;
A tomographic imaging apparatus, comprising: an imaging instruction unit that instructs the tomographic imaging unit that images the subject to perform detailed imaging of the detailed imaging area obtained by the detailed imaging area acquisition unit.

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