JP6853328B2 - Magnetic resonance imaging device and medical image processing method - Google Patents

Description

Embodiments of the present invention relate to a magnetic resonance imaging apparatus.

Magnetic Resonance Imaging (MRI) magnetically excites the nuclear spin of a subject placed in a static magnetic field with a Larmor frequency RF (Radio Frequency) pulse, and is accompanied by this excitation. This is an imaging method in which an image is reconstructed from an NMR (Nuclear Magnetic Resonance) signal generated.

For example, a standardized protocol has been established for cardiac examination methods using MRI. For example, the standardized protocol includes a plurality of body axis cross-sectional images (Axial), sagittal section images (Sagittal), and coronal section images (Coronal), which are called scout images or locator images. The flow of collecting a multi-slice image (Axial multi-slice) which is a cross-sectional view of the body axis of the body and then collecting a reference cross-sectional image is defined.

The reference cross-sectional image is a cross-sectional image based on the anatomical features of the heart, and is a left ventricular vertical long-axis image and a left ventricular horizontal long-axis image. ), Left / Right ventricular short-axis, Left / Right ventricular 2-chamber long-axis, Left (right) ventricular three-chamber Long-axis image (Left / Right ventricular 3-chamber long-axis), left (right) ventricular 4-chamber long-axis image, left (right) ventricular outflow tract image (Left / Right / Right ventricular 4-chamber long-axis) Right ventricular outflow tract), aortic valve image (Aorta valve), pulmonary valve image (Pulmonary valve), etc. The method of setting the reference cross-sectional image is also defined for various objects such as the brain, shoulders, and knees.

Japanese Unexamined Patent Publication No. 2006-55641 JP-A-2002-140689 Japanese Patent No. 4018303 Japanese Patent No. 5323194

SCMR (Society for Cardiovascular Magnetic Resonance), "Society for Cardiovascular Magnetic Resonance Protocol", [online], [Search on August 20, 2014], Internet <URL: http://scmr.jp/mri/pdf/ scmr_protocols_2007_jp.pdf>, <URL: http://scmr.jp/mri/pdf/scmr_protocols_2007.pdf>

An object to be solved by the present invention is to provide a magnetic resonance imaging apparatus capable of easily positioning a cross-sectional image by a user.

The magnetic resonance imaging apparatus of the embodiment includes a generation unit, an input unit, and a display control unit. The generation unit generates a plurality of cross-sectional images corresponding to a plurality of cross-sectional positions of the target for setting the cross-sectional positions of the main imaging based on the three-dimensional data including the target, and displays the plurality of cross-sectional images on the display unit. Display it. The input unit accepts a cross-sectional position setting operation. When the cross-sectional position where the cross-sectional position of one cross-sectional image and the cross-sectional position of the other cross-sectional image intersect is selected by the setting operation, the display control unit performs the other cross-sectional image. Highlight the image.

FIG. 1 is a functional block diagram showing a configuration of an MRI apparatus according to the first embodiment. FIG. 2 is a diagram showing an example of a plurality of reference cross-sectional images displayed in the display area of the display unit according to the first embodiment. FIG. 3 is a diagram for explaining an example in which, in the first embodiment, when the position of a feature portion is changed in a certain reference cross-sectional image, the cross-sectional position of another reference cross-sectional image is changed. FIG. 4 is a diagram for explaining an example in the case of highlighting the reference cross-sectional image in the first embodiment. FIG. 5 is a functional block diagram showing an example of the functional configuration of the control unit according to the first embodiment. FIG. 6 is a flowchart showing a processing procedure according to the first embodiment. FIG. 7 is a diagram showing an example of the data structure of the cross-sectional position definition information table according to the first embodiment. FIG. 8 is a diagram showing another example of the method of highlighting the reference cross-sectional image in the first embodiment. FIG. 9 is a diagram showing another example of the method of highlighting the reference cross-sectional image in the first embodiment. FIG. 10 is a diagram for explaining an example of processing executed by the display control unit when the process returns to step S6 again in the first modification of the first embodiment. FIG. 11 is a diagram for explaining an example of processing executed by the display control unit when the process returns to step S6 again in the first modification of the first embodiment. FIG. 12 is a diagram for explaining an example of processing executed by the MRI apparatus according to the second modification of the first embodiment. FIG. 13 is a diagram for explaining an example of processing executed by the MRI apparatus according to the second embodiment. FIG. 14 is a diagram for explaining an example of processing executed by the MRI apparatus according to the third embodiment. FIG. 15 is a diagram for explaining an example of how to set various reference cross sections when the “knee” is the target portion in the embodiment. FIG. 16 is a diagram for explaining an example of how to set various reference cross sections when the “knee” is the target portion in the embodiment. FIG. 17 is a diagram for explaining an example of how to set various reference cross sections when the “knee” is the target portion in the embodiment. FIG. 18 is a diagram for explaining an example of highlighting a reference cross-sectional image when an intersection line according to an embodiment is designated.

Hereinafter, the magnetic resonance imaging apparatus according to the embodiment (hereinafter, “MRI (Magnetic Resonance Imaging) apparatus” as appropriate) will be described with reference to the drawings. The embodiment is not limited to the following embodiment. In principle, the contents described in each embodiment can be applied to other embodiments as well.

(First Embodiment)
FIG. 1 is a functional block diagram showing the configuration of the MRI apparatus 100 according to the first embodiment. As shown in FIG. 1, the MRI apparatus 100 includes a static magnetic field magnet 1, a gradient magnetic field coil 2, a gradient magnetic field power supply 3, a sleeper 4, a sleeper control unit 5, a transmission coil 6, and a transmission unit 7. It includes a receiving coil 8, a receiving unit 9, a sequence control unit 10, and a computer 20. The MRI apparatus 100 does not include the subject P (for example, the human body) shown in the dotted frame in FIG. Further, the configuration shown in FIG. 1 is only an example. For example, the sequence control unit 10 and each unit in the calculator 20 may be appropriately integrated or separated.

The static magnetic field magnet 1 is a magnet formed in a hollow cylindrical shape (including a magnet having an elliptical cross section orthogonal to the axis of the cylinder), and generates a static magnetic field in the internal space. The static magnetic field magnet 1 is, for example, a permanent magnet. The static magnetic field magnet 1 may be a superconducting magnet. When the static magnetic field magnet 1 is a superconducting magnet, the MRI apparatus 100 includes a static magnetic field power supply (not shown), and the static magnetic field power supply supplies a current to the static magnetic field magnet 1. At this time, the static magnetic field magnet 1 is excited by receiving a current supply from the static magnetic field power source. Further, the static magnetic field power supply may be provided separately from the MRI apparatus 100.

The gradient magnetic field coil 2 is a coil formed in a hollow cylindrical shape (including a coil having an elliptical cross section orthogonal to the axis of the cylinder), and is arranged inside the static magnetic field magnet 1. The gradient magnetic field coil 2 is formed by combining three coils corresponding to the axes of X, Y, and Z that are orthogonal to each other, and these three coils individually supply current from the gradient magnetic field power supply 3. In response, a gradient magnetic field is generated in which the magnetic field strength changes along the X, Y, and Z axes. The gradient magnetic fields of the X, Y, and Z axes generated by the gradient magnetic field coil 2 are, for example, the gradient magnetic field Gs for slicing, the gradient magnetic field Ge for phase encoding, and the gradient magnetic field Gr for reading. The gradient magnetic field power supply 3 supplies a current to the gradient magnetic field coil 2.

The sleeper 4 is provided with a top plate 4a on which the subject P is placed, and under the control of the sleeper control unit 5, the top plate 4a is placed in a state where the subject P is placed, and the cavity of the gradient magnetic field coil 2 is formed. Insert it into the imaging port). Normally, the sleeper 4 is installed so that the longitudinal direction is parallel to the central axis of the static magnetic field magnet 1. The sleeper control unit 5 drives the sleeper 4 to move the top plate 4a in the longitudinal direction and the vertical direction under the control of the calculator 20.

The transmission coil 6 is arranged inside the gradient magnetic field coil 2 and receives an RF pulse from the transmission unit 7 to generate a high-frequency magnetic field. The transmission unit 7 supplies the transmission coil 6 with an RF pulse corresponding to a Larmor frequency determined by the type of target atom and the magnetic field strength.

The receiving coil 8 is arranged inside the gradient magnetic field coil 2 and receives a magnetic resonance signal (hereinafter, appropriately “MR signal”) emitted from the subject P due to the influence of a high-frequency magnetic field. When the receiving coil 8 receives the MR signal, it outputs the received MR signal to the receiving unit 9.

The transmission coil 6 and the reception coil 8 described above are merely examples. It may be configured by combining one or a plurality of coils having only a transmitting function, a coil having only a receiving function, or a coil having a transmitting / receiving function.

The receiving unit 9 detects the MR signal output from the receiving coil 8 and generates MR data based on the detected MR signal. Specifically, the receiving unit 9 generates MR data by digitally converting the MR signal output from the receiving coil 8. Further, the receiving unit 9 transmits the generated MR data to the sequence control unit 10. The receiving unit 9 may be provided on the gantry device side including the static magnetic field magnet 1, the gradient magnetic field coil 2, and the like.

The sequence control unit 10 takes an image of the subject P by driving the gradient magnetic field power supply 3, the transmission unit 7, and the reception unit 9 based on the sequence information transmitted from the computer 20. Here, the sequence information is information that defines a procedure for performing imaging. The sequence information includes the strength of the current supplied by the gradient magnetic field power supply 3 to the gradient magnetic field coil 2, the timing of supplying the current, the strength of the RF pulse supplied by the transmission unit 7 to the transmission coil 6, the timing of applying the RF pulse, and the reception. The timing at which the unit 9 detects the MR signal and the like are defined. For example, the sequence control unit 10 is an integrated circuit such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field Programmable Gate Array), and an electronic circuit such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit).

When the sequence control unit 10 receives the MR data from the receiving unit 9 as a result of driving the gradient magnetic field power supply 3, the transmitting unit 7, and the receiving unit 9 to image the subject P, the sequence control unit 10 transfers the received MR data to the computer 20. Forward.

The computer 20 controls the entire MRI apparatus 100, generates an image, and the like. The computer 20 includes an interface unit 21, an image generation unit 22, a storage unit 23, an input unit 24, a display unit 25, and a control unit 26.

The interface unit 21 transmits sequence information to the sequence control unit 10 and receives MR data from the sequence control unit 10. When the interface unit 21 receives the MR data, the interface unit 21 stores the received MR data in the storage unit 23. The MR data stored in the storage unit 23 is arranged in the k-space by the control unit 26. As a result, the storage unit 23 stores k-space data.

The image generation unit 22 reads the k-space data from the storage unit 23, and generates an image by performing reconstruction processing such as Fourier transform on the read k-space data.

The storage unit 23 stores MR data received by the interface unit 21, k-space data arranged in the k-space by the control unit 26, image data generated by the image generation unit 22, and the like. Further, the storage unit 23 stores the cross-section position definition information table 23a. The cross-section position definition information table 23a will be described later. The storage unit 23 is, for example, a RAM (Random Access Memory), a semiconductor memory element such as a flash memory, a hard disk, an optical disk, or the like.

The input unit 24 receives various instructions and information inputs from the operator. The input unit 24 is, for example, a pointing device such as a mouse or a trackball, or an input device such as a keyboard. The display unit 25 displays various GUIs (Graphical User Interfaces), images generated by the image generation unit 22, and the like under the control of the control unit 26. The display unit 25 is, for example, a display device such as a liquid crystal display.

The control unit 26 controls the entire MRI apparatus 100, and controls imaging, image generation, image display, and the like. For example, the control unit 26 receives an input of imaging conditions on the GUI, generates sequence information according to the received imaging conditions, and transmits the generated sequence information to the sequence control unit 10. For example, the control unit 26 is an integrated circuit such as an ASIC or FPGA, or an electronic circuit such as a CPU or MPU. As will be described later, the control unit 26 includes each unit for allowing the user to easily change the cross-sectional position of the reference cross-sectional image.

Here, the outline of the processing by the MRI apparatus 100 according to the first embodiment will be described. For example, the MRI apparatus 100 first collects a multi-slice image in a preparatory scan prior to collecting a reference cross-sectional image in an imaging scan, stores the multi-slice image in a storage unit 23, and stores a plurality of reference cross-sections from the multi-slice image. The cross-sectional position of the image is automatically detected. To explain with a more detailed example, the MRI apparatus 100 automatically detects a feature portion related to the target portion (target) from the multi-slice image, and calculates the cross-sectional position using the automatically detected position of the feature portion. , Automatically detect the cross-sectional position. That is, the cross-sectional position is defined by the position of the feature portion. The imaging scan is, for example, imaging for collecting images mainly used for diagnosis (also referred to as “main imaging” or the like), and the preparatory scan is, for example, typically preceded by this imaging scan. Imaging (also called "preparatory imaging" or the like) is performed.

The multi-slice image is data composed of a plurality of slice images collected by a 2D sequence. The multi-slice image is an example of three-dimensional data. Note that the volume data collected by the 3D sequence can be used instead of the multi-slice image. The 2D sequence referred to here is a pulse sequence that collects a two-dimensional cross-sectional image by encoding one or a plurality of positions along the slice direction in the phase encoding direction and the readout direction. The 3D sequence is a pulse sequence that collects three-dimensional volume data by encoding not only in the phase encoding direction and the readout direction but also in the slice direction. Further, the 2D sequence and the 3D sequence may be a radial scan sequence that collects the lead-out direction at various angles.

Then, the MRI apparatus 100 generates a reference cross-sectional image corresponding to a plurality of automatically detected cross-sectional positions from the multi-slice image. Hereinafter, the case where the multi-slice image is data including the “heart” as the target site will be described as an example. Then, the MRI apparatus 100 displays the generated reference cross-sectional images side by side on the display unit 25. FIG. 2 is a diagram showing an example of a plurality of reference cross-sectional images displayed in the display area of the display unit 25 according to the first embodiment. For example, as shown in the example of FIG. 2, the MRI apparatus 100 has a body axis cross-sectional image 80 and a left ventricular vertical long axis image in the first row from the top, from left to right, in the display area of the display unit 25. 81, the left ventricular horizontal long axis image 82, the left ventricular short axis image 83, and the right ventricular short axis image 84 are displayed. Further, in the display area of the display unit 25, the MRI apparatus 100 has a left ventricular four-chamber long-axis image 85, a left ventricular two-chamber long-axis image 86, and a left ventricular three-chamber in the second row from the top from left to right. The long axis image 87, the left ventricular outflow tract image 88, and the aortic valve image 89 are displayed. Further, in the display area of the display unit 25, the MRI apparatus 100 has a right ventricular four-chamber long-axis image 90, a right ventricular two-chamber long-axis image 91, and a right ventricular three-chamber in the third row from the top from left to right. The long axis image 92, the right ventricular outflow tract image 93, and the pulmonary valve image 94 are displayed. The images indicated by the reference numerals "81" to "94" are reference cross-sectional images, and the images indicated by the reference numerals "80" are slice images of one of the multi-slice images. Hereinafter, each of the above-mentioned reference cross-sectional images indicated by the reference numerals “81” to “94” may be simply referred to as “reference cross-sectional image”. Further, hereinafter, the slice image indicated by the reference numeral “80” may be simply referred to as a “slice image”.

Further, in the example of FIG. 2, marks indicating the positions of characteristic parts related to the heart are superimposed on the slice image 80 and the plurality of reference cross-sectional images 81 to 94. In the example of FIG. 2, the black-painted square mark, the black-painted heart-shaped mark, the black-painted star-shaped mark, and the black-painted triangular mark shown in the slice image 80 and the plurality of reference cross-sectional images 81 to 94 are shown. , The white square mark, the white heart-shaped mark, the white star-shaped mark, and the white triangular mark indicate the cross-sectional positions of the slice image 80 and the plurality of reference cross-sectional images 81 to 94, respectively. It is information indicating the position of the characteristic part for definition. For example, a black square mark is information indicating the position of the mitral valve of the heart. The black-painted star-shaped mark is information indicating the position of the apex of the left ventricle of the heart. The black-painted heart-shaped mark is information indicating the central position of the left ventricle (center of the left ventricle), and is the midpoint between the mitral valve and the apex of the left ventricle. The white square mark is information indicating the position of the tricuspid valve of the heart. The white star-shaped mark is information indicating the position of the apex of the right ventricle of the heart. The white heart-shaped mark is information indicating the center position of the right ventricle (center of the right ventricle), and is the midpoint between the positions of the tricuspid valve and the apex of the right ventricle. The white triangular mark is information indicating the position of the right ventricular outflow tract of the heart. In addition, these marks are also an example of information indicating the position of the featured portion. In the example of FIG. 2, a case is shown in which all the reference cross-sectional images among the plurality of reference cross-sectional images 81 to 94 have marks corresponding to the feature portions, but among the plurality of reference cross-sectional images 81 to 94. It is sufficient that at least one reference cross-sectional image has a mark corresponding to the featured portion.

In the example of FIG. 2, for example, the cross-sectional position of the left ventricular vertical long axis image 81 is a cross-sectional position that passes through the position of the mitral valve and the position of the apex of the left ventricle and is parallel to the cephalopod direction. That is, the cross-sectional position of the left ventricular vertical long axis image 81 is defined by the position of a characteristic portion such as the mitral valve or the apex of the left ventricle. In the example of FIG. 2, the left ventricular vertical long axis image 81 has a black square mark indicating the position of the mitral valve, a black star-shaped mark indicating the position of the apex of the left ventricle, and a center of the left ventricle. A black heart-shaped mark indicating the position of is superimposed. Similarly, in the other reference cross-sectional images 82 to 94 and the slice image 80, marks indicating the positions of the feature portions that define the cross-sectional positions are superimposed.

Further, in the example of FIG. 2, each of the reference cross-sectional images 81 to 94 is superposed with a mark of an intersection line indicating a position where the cross-sectional position of its own reference cross-sectional image and the cross-sectional position of another cross-sectional image intersect. ing.

Here, in each of the plurality of reference cross-sectional images 81 to 94, the user can change the position of the feature portion. An example of a method of changing the position of the feature portion by the user will be described. For example, the user can specify and change the position of the feature portion that defines the cross-sectional position of the reference cross-sectional image in each of the plurality of reference cross-sectional images 81 to 94 displayed on the display unit 25. To give a more specific example, the user specifies, in each of the plurality of reference cross-sectional images 81 to 94, a mark indicating the position of the feature portion that defines the cross-sectional position of the reference cross-sectional image, and the designated mark. By changing the position of, the position of the featured part can be changed.

Here, if the position of the feature portion is changed in a certain reference cross-sectional image, the cross-sectional position of another reference cross-sectional image may be changed. This case will be described with reference to FIG. FIG. 3 is a diagram for explaining an example in which, in the first embodiment, when the position of the feature portion is changed in a certain reference cross-sectional image, the cross-sectional position of another reference cross-sectional image is changed. .. In the example of FIG. 3, the user operates the mouse of the input unit 24 to align the pointer 24a with the black square mark on the left chamber vertical long axis image 81, and then clicks the mouse to make the black square. The case where the mitral valve is specified by designating the mark of, and then the position of the black-painted square mark is changed by moving the pointer 24a is shown. In this way, when the position of the mark indicating the position of the mitral valve in the left ventricular vertical long axis image 81 is changed, the left ventricular horizontal long axis image 82, left, in which the cross-sectional position is defined using the position of the mitral valve. Cross-sectional positions of six reference cross-sectional images: left ventricular four-chamber long-axis image 83, left ventricular four-chamber long-axis image 85, left ventricular two-chamber long-axis image 86, left ventricular three-chamber long-axis image 87, and right ventricular four-chamber long-axis image 90. Is changed, and six reference cross-sectional images after the cross-sectional position is changed are displayed as shown in the example of FIG. However, as it is, since the number of the reference cross-sectional images displayed (in the example of FIG. 3, the number of the reference cross-sectional images is “14”) is large, the user can see the mitral valve in the left ventricular vertical long axis image 81. When the position of the mark indicating the position of is changed, it is difficult to grasp which of the other plurality of reference cross-sectional images 82 to 94 the reference cross-sectional image has changed the cross-sectional position.

Therefore, in the MRI apparatus 100 according to the present embodiment, in a certain reference cross-sectional image, a mark indicating the position of the feature portion whose position is to be changed is designated, and when the position of the designated mark is changed, the position is changed. Compare other reference section images whose section position is defined using feature sites whose position is indicated by the modified mark with one reference section image described above and the rest of the reference section image excluding the other reference section image. To highlight (highlight). Further, for example, the MRI apparatus 100 can prevent the highlighting from being performed when the mark is not specified, for example.

FIG. 4 is a diagram for explaining an example in the case of highlighting the reference cross-sectional image in the first embodiment. For example, as shown in the example of FIG. 3, when the position of the mark indicating the position of the mitral valve is changed in the left ventricular vertical long axis image 81, the MRI apparatus 100 is changed to the example of FIG. As shown, the left ventricular horizontal long axis image 82, the left ventricular short axis image 83, the left ventricular four cavity long axis image 85, the left ventricular two cavity long axis image 86, the left ventricular three cavity long axis image 87, and the right ventricular four cavity image The six reference cross-sectional images of the long-axis image 90 are highlighted in comparison with the reference cross-sectional images 81, 84, 88, 91-94 other than the six reference cross-sectional images. The example of FIG. 4 shows a case where the six reference cross-sectional images are emphasized by thickening the frames of the above-mentioned six reference cross-sectional images as an example of highlighting. In this way, the MRI apparatus 100 specifies a mark indicating the position of the feature portion whose position is to be changed in a certain reference cross-sectional image, and when the position of the designated mark is changed, the designated mark is used. Highlights another reference cross-sectional image whose cross-sectional position is changed by changing the position of the featured portion indicated by. Therefore, according to the MRI apparatus 100, it is possible for the user to easily grasp which reference cross-sectional image the cross-sectional position changes with the change in the position of the mark indicating the position of the feature portion in a certain reference cross-sectional image. .. Therefore, according to the MRI apparatus 100, the user can easily position the reference cross-sectional image.

Then, when the positioning of the cross-sectional positions of the plurality of reference cross-sectional images displayed on the display unit 25 is completed, the MRI apparatus 100 executes an imaging scan at the changed cross-sectional positions.

Next, an example of the functional configuration of the control unit 26 according to the present embodiment will be described. FIG. 5 is a functional block diagram showing an example of the functional configuration of the control unit 26 according to the first embodiment. As shown in the example of FIG. 5, the control unit 26 includes a detection unit 26a, a generation unit 26b, a change unit 26c, and a display control unit 26d.

The detection unit 26a acquires a multi-slice image collected in the preparatory scan and stored in the storage unit 23 from the storage unit 23, and automatically detects the cross-sectional positions of a plurality of reference cross-sectional images from the acquired multi-slice image. For example, the detection unit 26a includes a left ventricular vertical long axis image, a left ventricular horizontal long axis image, a left ventricular short axis image, a right ventricular short axis image, a left ventricular four-chamber long-axis image, a left ventricular two-chamber long-axis image, and a left ventricle. Ventricular three-chamber long-axis image, left ventricular outflow tract image, aortic valve image, right ventricular four-chamber long-axis image, right ventricular two-chamber long-axis image, right ventricular three-chamber long-axis image, right ventricular outflow tract image, and pulmonary artery The cross-sectional position of each of the 14 reference cross-sectional images of the valve image is detected. Then, the detection unit 26a stores a plurality of automatically detected cross-sectional positions in the storage unit 23. The plurality of cross-sectional positions automatically detected by the detection unit 26a are the cross-sectional positions of the plurality of cross-sectional images collected by the imaging scan. Hereinafter, the cross-sectional position automatically detected by the detection unit 26a may be referred to as a “first cross-sectional position”.

The generation unit 26b generates a reference cross-sectional image corresponding to each of the plurality of first cross-sectional positions, and causes the display unit 25 to display the generated reference cross-sectional images. For example, the generation unit 26b first acquires a multi-slice image and a plurality of first cross-sectional positions from the storage unit 23. Then, the generation unit 26b generates a reference cross-sectional image corresponding to each of the plurality of first cross-sectional positions by MPR (Multi-Planar Reconstruction) processing from the multi-slice image. Hereinafter, the reference cross-sectional image generated by the generation unit 26b may be referred to as a “first cross-sectional image”. Then, the generation unit 26b causes the display unit 25 to display the first cross-sectional image. For example, as shown in the example of FIG. 2, the generation unit 26b displays a plurality of first cross-sectional images 81 to 94 on which the above-mentioned various marks are superimposed together with the body axis cross-sectional image 80 on the display unit 25. Let me. In addition, the generation unit 26b stores the first cross-sectional image in the storage unit 23.

In a certain first cross-sectional image, when the position of the mark is changed by the user, the change unit 26c defines the cross-sectional position using the position of the changed feature portion indicated by the changed mark. The cross-sectional position of the first cross-sectional image of is calculated. Then, the changing unit 26c stores the calculated cross-sectional position in the storage unit 23. Hereinafter, the cross-sectional position calculated by the changing portion 26c may be referred to as a “second cross-sectional position”.

The display control unit 26d generates a reference cross-sectional image that is a reference cross-sectional image corresponding to the second cross-sectional position and is emphasized more than other reference cross-sectional images such as by making the frame thicker, and displays the generated reference cross-sectional image. Display on 25. For example, the display control unit 26d first acquires the multi-slice image and the second cross-sectional position from the storage unit 23. Then, the display control unit 26d generates a reference cross-sectional image corresponding to the second cross-sectional position from the multi-slice image by MPR processing. At this time, the display control unit 26d generates an emphasized reference cross-sectional image such as by thickening the frame. Hereinafter, the reference cross-sectional image generated by the display control unit 26d may be referred to as a “second cross-sectional image”. Then, the display control unit 26d causes the display unit 25 to display the second cross-sectional image. Further, the display control unit 26d stores the generated second cross-sectional image in the storage unit 23.

Next, the flow of processing executed by the MRI apparatus 100 according to the present embodiment will be described. FIG. 6 is a flowchart showing a processing procedure according to the first embodiment. Here, in the first embodiment, the types of reference cross-sectional images are left ventricular vertical long axis image, left ventricular horizontal long axis image, left ventricular short axis image, right ventricular short axis image, and left ventricular four cavity long axis image. , Left ventricular two-chamber long-axis image, left ventricular three-chamber long-axis image, left ventricular outflow tract image, aortic valve image, right ventricular four-chamber long-axis image, right ventricular two-chamber long-axis image, right ventricular three-chamber long-axis image , Right ventricular outflow tract image, and pulmonary valve image, 14 types of examinations are assumed.

As shown in the example of FIG. 6, the sequence control unit 10 drives the gradient magnetic field power supply 3, the transmission unit 7, and the reception unit 9 of the MRI apparatus 100 so as to collect the multi-slice image (step S1). In the present embodiment, the multi-slice image is, for example, a plurality of body axis cross-sectional images. The multi-slice image also includes the heart. The heart is an example of a target site. The sequence control unit 10 performs MRI (ECG: Electro Cardio Gram) synchronization, for example, limiting the collection timing to the diastole period, and collecting MR data of the multi-slice image while holding a breath. It drives the gradient magnetic field power supply 3, the transmission unit 7, and the reception unit 9 of the device 100. Further, the sequence control unit 10 uses, for example, 2D FFE (Fast Field Echo), 2D SSFP (Steady-State Free Precession), or the like for collecting MR data of a multi-slice image. The sequence control unit 10 transmits the collected MR data to the image generation unit 22 via the interface unit 21. When the image generation unit 22 receives the MR data, the image generation unit 22 generates a multi-slice image using the received MR data, and stores the generated multi-slice image in the storage unit 23. The multi-slice image may be a plurality of sagittal section images or coronal section images.

Next, the detection unit 26a detects (automatically detects) each cross-sectional position (first cross-sectional position) of the above-mentioned 14 types of reference cross-sectional images (step S2). The cross-sectional position will be described. The cross-sectional position means, for example, a position representing a plane in a three-dimensional image space, and is represented by a plurality of parameters. In the following description, these parameters will be referred to as "positional parameters". As shown in the following equations (1) and (2), the position parameter is represented by, for example, a center coordinate point o and two unit vectors u and v that are orthogonal to each other.

The detection of the cross-sectional position is to obtain the position parameters o, u, and v. The detection unit 26a stores the position parameter for each detected reference cross-sectional image in the storage unit 23. The position parameter is not limited to the above-mentioned expression method, and may be expressed not in the three-dimensional image space but in the three-dimensional device space determined based on the center of the magnetic field of the MRI device 100, the longitudinal direction of the bed, and the like. Alternatively, it may be represented by three coordinate points instead of the center coordinate point and two orthogonal unit vectors. That is, any expression method may be used in which the cross-sectional position is geometrically and uniquely determined.

For example, the detection unit 26a is a characteristic part of the heart such as a mitral valve, a tricuspid valve, an aortic valve, a pulmonary valve, a left (right) ventricular apex, a left (right) ventricular outflow tract, and a left (right) anterior wall of the ventricle. The position of the feature part in the multi-slice image is automatically detected by performing template matching with the multi-slice image using the template of the peripheral image pattern, and the position parameter of each reference cross-sectional image is set based on the detected feature part. calculate. Here, it is assumed that the template as described above is generated in advance before executing the template matching. For example, the cross-sectional position of the left ventricular four-chamber long-axis image, which is one of the reference cross-sectional images, is a plane passing through three points of the mitral valve position m, the tricuspid valve position t, and the left ventricular apex position a. .. That is, the cross-sectional position of the left ventricular four-chamber long-axis image is defined by the positions of three points: the position m of the mitral valve, the position t of the tricuspid valve, and the position a of the apex of the left ventricle. Here, when the position m of the mitral valve, the position t of the tricuspid valve, and the position a of the apex of the left ventricle are expressed by the following equation (3), the position parameter o indicating the cross-sectional position of the left ventricular four-chamber long-axis image, u and v can be expressed by the following equation (4).

In the equation (4), "(tm) xv" means the outer product of the vector (tm) and the vector v, and "((tm) xv) xv" is It means the outer product of the vector ((tm) × v) and the vector v.

Further, the detection of the cross-sectional position of the reference cross-sectional image is not limited to template matching. For example, the detection unit 26a constructs a classifier in advance by machine learning from the peripheral image pattern of the feature site of the heart, and automatically detects the position of the feature site in the multi-slice image using this classifier. May be good. Further, the detection unit 26a can also detect the cross-sectional position of the reference cross-sectional image by receiving the input of the position of the characteristic portion of the heart by the operator via the input unit 24. However, since this work is very complicated and time-consuming, a method of automatically detecting the detection position of each reference cross-sectional image is usually preferable.

Next, the generation unit 26b acquires the multi-slice image from the storage unit 23, and generates a reference cross-sectional image (first cross-sectional image) corresponding to each of the plurality of first cross-sectional positions from the multi-slice image by MPR processing. Then, the first cross-sectional image is displayed on the display unit 25 together with the slice image (step S3). For example, the generation unit 26b causes the display unit 25 to display a slice image on which the above-mentioned various marks are superimposed and a plurality of first cross-sectional images. In addition, the generation unit 26b stores the first cross-sectional image in the storage unit 23.

Next, the change unit 26c determines whether or not the user has changed the position of the mark via the input unit 24 (step S4).

When the changing unit 26c determines that the user has changed the position of the mark via the input unit 24 (step S4; Yes), the cross-sectional position is changed by using the position of the feature portion indicated by the mark whose position has been changed. With respect to the defined reference cross-sectional image, a new cross-sectional position (second cross-sectional position) is calculated using the position of the changed feature portion indicated by the mark whose position has been changed (step S5). For example, the changing unit 26c calculates the three-dimensional position in the three-dimensional image space from the two-dimensional position of the changed mark on the reference cross-sectional image in which the position of the mark is changed. Then, the changing unit 26c refers to the cross-sectional position definition information table 23a, and specifies another reference cross-sectional image in which the cross-sectional position is defined by using the position of the feature portion indicated by the mark whose position has been changed.

Here, the cross-section position definition information table 23a will be described. The cross-sectional position definition information table 23a is a table in which a reference cross-sectional image and a feature portion that defines the cross-sectional position of the reference cross-sectional image are associated and registered. That is, the reference cross-sectional image is determined to pass through a plurality of feature sites. Alternatively, the reference cross-sectional image is defined to pass through the points determined by the plurality of feature sites. Alternatively, the reference cross-sectional image is defined to pass through one feature site and a point determined by another feature site. FIG. 7 is a diagram showing an example of the data structure of the cross-section position definition information table 23a according to the first embodiment. The cross-section position definition information table 23a shown in the example of FIG. 7 has each item of “ID (Identification)” and “definition parameter”. In the item of "ID", identification information indicating the type of the reference cross-sectional image is registered. In the "Definition parameter" item, the feature part that defines the cross-sectional position of the reference cross-sectional image of the type indicated by the identification information registered in the "ID" item and the information indicating the conversion formula from the feature part to the position parameter are registered. Will be done. In the first record of the cross-sectional position definition information table 23a in the example of FIG. 7, the cross-sectional position of the left ventricular four-chamber long-axis image indicated by the identification information “L4CH” is the position of the mitral valve, the position of the tricuspid valve, and the left. It is shown that it is defined by the position of three points of the position of the ventricular apex.

For example, when the feature portion whose position is indicated by the mark whose position has been changed is a mitral valve, the change portion 26c refers to the cross-sectional position definition information table 23a, and the mitral valve is an item of "definition parameter". Identify the records registered in. Then, the change unit 26c specifies the identification information registered in the "ID" item of the specified record. Then, the specific unit 26c identifies another reference cross-sectional image whose cross-sectional position is defined by using the position of the characteristic portion indicated by the mark whose position has been changed by specifying the reference cross-sectional image of the type indicated by the specified identification information. To identify.

The cross-section position definition information table 23a is not limited to the table having the data structure shown in the example of FIG. 7. The cross-sectional position definition information table 23a may have any data structure as long as the information in which the reference cross-sectional image and the feature portion defining the cross-sectional position of the reference cross-sectional image are registered is registered.

Then, the changing unit 26c is the same as the above equation (4) based on the calculated three-dimensional position for the reference cross-sectional image in which the cross-sectional position is defined by using the position of the feature portion indicated by the mark whose position has been changed. The changed cross-sectional position is calculated by calculating the changed position parameter using the formula of.

Here, in the example of FIG. 2 above, the case where the user changes the position of the mark indicating the position of the mitral valve of the left ventricular vertical long axis image 81 will be described. In this case, the changing portion 26c determines the three-dimensional position in the three-dimensional space from the two-dimensional position of the changed mark (the two-dimensional position of the black-painted square mark) on the left chamber vertical long axis image 81. calculate. Then, the change portion 26c has a left ventricular horizontal long axis image 82, a left ventricular short axis image 83, a left ventricular four cavity long axis image 85, and a left ventricle whose cross-sectional position is defined using the position of the mitral valve indicated by the mark. For each of the two-chamber long-axis image 86, the left ventricular three-chamber long-axis image 87, and the right ventricular four-chamber long-axis image 90, the changed position parameters are calculated using the same equation as in the above equation (4). As a result, the changed cross-sectional position is calculated.

Further, in the example of FIG. 2 above, a case where the user changes the position of the mark indicating the position of the right ventricular outflow tract of the right ventricular three-chamber long axis image 92 will be described. In this case, the changing unit 26c calculates the three-dimensional position in the three-dimensional space from the two-dimensional position (white triangular mark) of the changed mark on the right chamber three-chamber long-axis image 92. Then, the modified portion 26c has the same equation as the above equation (4) for each of the right ventricular outflow tract image 93 and the pulmonary valve image 94 whose cross-sectional position is defined by using the position of the right ventricular outflow tract indicated by the mark. By calculating the changed position parameter using, the changed cross-sectional position is calculated.

Next, the display control unit 26d is a reference cross-sectional image corresponding to the changed cross-sectional position by using the changed cross-sectional position (second cross-sectional position), and is different from other reference cross-sectional images such as thickening the frame. A reference cross-sectional image (second cross-sectional image) also emphasized is generated, and the generated reference cross-sectional image is highlighted on the display unit 25 (step S6). As a result, the display control unit 26d can emphasize and display the generated reference cross-sectional image in comparison with other reference cross-sectional images. Then, the display control unit 26d causes the display unit 25 to display the generated reference cross-sectional image. For example, the display control unit 26d has six second cross-sectional images (left ventricular horizontal long axis image 82, left ventricular short axis image 83, left ventricular four cavities) with thickened frames, as shown in the example of FIG. The long axis image 85, the left ventricular two-chamber long-axis image 86, the left ventricular three-chamber long-axis image 87, and the right ventricular four-chamber long-axis image 90) are displayed on the display unit 25. As a result, the six reference cross-sectional images are displayed with emphasis as compared with the reference cross-sectional images 81, 84, 88, 91-94. In the second modification, an example of highlighting when a feature part is specified (an example of canceling the highlighting when the position of the mark indicating the feature part is changed) has been described. , The embodiment is not limited to this. After the feature portion is designated, the change of the mark position is started, and for highlighting after the start, various embodiments described above can be combined.

Then, the display control unit 26d returns to step S4. That is, the display control unit 26d highlights the reference cross-sectional image while the position of the mark indicating the position of the feature portion is changed (while the change operation is being performed via the input unit 24). As a result, while the position of the feature portion is changed, the user can easily grasp which reference cross-sectional image the cross-sectional position changes with the change of the position of the feature portion in a certain reference cross-sectional image. .. Therefore, the user can easily position the reference cross-sectional image. Then, when the change in the position of the mark indicating the position of the feature portion is completed, the display control unit 26d cancels the highlighting of the reference cross-sectional image.

In addition, even when the change of the mark position is completed, the display control unit 26d does not cancel the highlighting of the reference cross-sectional image, and the user indicates the position of the feature portion via the input unit 24. The reference cross-sectional image may continue to be highlighted until it is determined by the change section 26c that the position has been newly changed. In this way, even after the change operation is completed, the highlighting is continued until the next change operation is started, so that the user can cancel the highlighting of the reference cross-sectional image at the end of the change of the mark position. Can confirm the changed reference cross-sectional image more carefully. Therefore, the user can more easily position the reference cross-sectional image. In the above description, an example in which the highlighting is canceled when the next change operation is started has been described, but the embodiment is not limited to this. For example, the highlighting may be canceled as a predetermined time elapses after the change operation is completed, and other triggers may be used.

Further, when the changing unit 26c determines that the position of the feature portion has not been changed via the input unit 24 (step S4; No), the change unit 26c cross-sections the reference cross-sectional image from the user via the input unit 24. It is determined whether the notification indicating that the positioning of the position is completed (positioning completion notification) has been received (step S7). When the changing unit 26c determines that the positioning completion notification has not been received (step S7; No), the process returns to step S4 described above.

On the other hand, when it is determined that the positioning completion notification has been received (step S7; Yes), the sequence control unit 10 drives the gradient magnetic field power supply 3, the transmission unit 7, and the reception unit 9 of the MRI apparatus 100 to be positioned. An imaging scan for collecting a plurality of cross-sectional images is performed using the plurality of cross-sectional positions (step S8), and the process is completed.

The MRI apparatus 100 according to the first embodiment has been described above. According to the MRI apparatus 100, as described above, the user can easily position the reference cross-sectional image.

The method of highlighting the reference cross-sectional image in the first embodiment is not limited to the method of thickening the frame as shown in FIG. The reference cross-sectional image to be highlighted and the reference cross-sectional image not to be highlighted may be displayed in different display modes. For example, the type and color of the frame may be displayed in different display modes. Further, a shadow may be added around the frame of the reference cross-sectional image to be highlighted, or light reflection, brilliance, blurring, and chamfering may be expressed in the frame of the reference cross-sectional image to be highlighted. Further, the reference cross-sectional image to be highlighted may be highlighted. The highlight display is, for example, a display method in which the background color is highlighted. Further, highlighting the reference cross-sectional image to be highlighted includes a case where the reference cross section to be highlighted is displayed on the display unit 25 and the reference cross section not to be highlighted is not displayed on the display unit 25.

8 and 9 are views showing another example of the method of highlighting the reference cross-sectional image in the first embodiment. For example, as shown in the example of FIG. 8, the reference cross-sectional images 80, 81, 84, 88, 89 that are not the objects of highlighting are larger than the sizes of the reference cross-sectional images 82, 83, 85-87, 90 that are the objects of highlighting. , 91-94 can be reduced in size. Further, as shown in the example of FIG. 9, the reference cross-sectional images 80, 81, 84, 88, 89 that are not the objects of highlighting are more than the contrasts of the reference cross-sectional images 82, 83, 85 to 87, 90 that are the objects of highlighting. , 91-94 sizes can also be reduced in contrast.

(First modification of the first embodiment)
In the MRI apparatus 100 according to the first embodiment described above, the case where the second cross-sectional image is highlighted while the position of the mark indicating the position of the feature portion is changed has been described, but the position of the mark is Even after the change, the second sectional image may be continuously highlighted until the positioning completion notification is received. Therefore, such an embodiment will be described as a first modification of the first embodiment.

In the MRI apparatus according to the first modification, the processing when returning from step S6 to step S4 is different from that of the MRI apparatus 100 according to the first embodiment. Therefore, an example of processing when returning from step S6 to step S4 in the MRI apparatus according to the first modification will be described with reference to FIGS. 10 and 11. For example, when returning from step S6 to step S4, the display unit 25 has a highlighted reference cross-sectional image (second cross-sectional image).

Here, the case where the highlighted reference cross-sectional images 82, 83, 85 to 87, 90 as shown in the example of FIG. 4 are present will be described. The example of FIG. 4 above shows a case where the reference cross-sectional images 82, 83, 85 to 87, 90 are highlighted because the position of the mark indicating the position of the mitral valve of the reference cross-sectional image 81 is changed. .. In such a case, for example, when the position of the mark indicating the position of the feature portion of the reference cross-sectional image 82 is changed, it is determined in step S4 that the position of the mark indicating the position of the feature portion has been changed. , Step S5 and step S6 are performed again. In the MRI apparatus according to the first modification, the reference cross-sectional image that has been highlighted up to that point is highlighted as it is in steps S5 and S6. That is, in the MRI apparatus according to the first modification, the display control unit 26d continues to highlight the already highlighted reference cross-sectional image as it is even after the position of the feature portion is changed. Therefore, according to the MRI apparatus according to the first modification, after the operation of changing the feature portion is completed, the cross-sectional position of which reference cross-sectional image is changed according to the change of the position of the feature portion in a certain reference cross-sectional image. It is possible to let the user know whether or not to do so over time. Therefore, according to the MRI apparatus according to the first modification, the user can more easily position the reference cross-sectional image.

The change unit 26c stores the position parameters before and after the change in the position of the feature portion in the storage unit 23, and the display control unit 26d acquires the position parameters before and after the change in the position of the feature portion stored in the storage unit 23. However, it is also possible to generate and display a reference cross-sectional image before and after the change in the position of the feature portion using the acquired position parameter. As a result, the user can confirm the reference cross-sectional image before and after the change of the position of the feature portion. Therefore, for example, the user can be made to judge whether or not the correction of the position of the feature portion is successful.

Here, when the type of the characteristic portion of the reference cross-sectional image 82 whose position is indicated by the black-painted square mark whose position has been changed is the mitral valve, the position of the mitral valve of the reference cross-sectional image 82 is corrected. Is completed, it is considered unlikely that the reference cross-sectional image 82 needs to be continuously highlighted. Therefore, in step S6, the display control unit 26d cancels the highlighting of the reference cross-sectional image 82 as shown in FIG. That is, in step S6, the display control unit 26d is a black-painted quadrangle in the reference cross-sectional image 82 highlighted in one of the reference cross-sectional images 82, 83, 85-87, 90 highlighted on the display unit 25. When the position of the mark is changed, the type of the feature portion whose position is indicated by the black-painted square mark is the black-painted black-painted image whose position has already been changed in the reference section image 81 other than the reference section image 82. When the type of the feature portion whose position is indicated by the square mark is the same, the highlighting of the reference cross-sectional image 82 is canceled. In this way, the correction of the position of the mitral valve is completed and the highlighting of the reference cross-sectional image 82, which is considered to be less necessary to continue highlighting, is canceled, and the correction of the position of the mitral valve is not completed. Such reference cross-sectional images 83, 85 to 87, 90, which are considered to have a high need to be continuously highlighted, are continuously highlighted. Therefore, appropriate highlighting can be performed. Note that FIG. 10 is a diagram for explaining an example of processing executed by the display control unit 26d when the process returns to step S6 again in the first modification of the first embodiment.

On the other hand, when the type of the characteristic portion of the reference cross-sectional image 82 whose position is indicated by the black-painted star-shaped mark whose position has been changed is the apex of the left ventricle, the position of the mitral valve of the reference cross-sectional image 82 is corrected. Is incomplete, so it is highly necessary to continue highlighting the reference cross-sectional image 82. Therefore, in step S6, the display control unit 26d does not cancel the highlighting of the reference cross-sectional image 82 as shown in FIG. As a result, the reference cross-sectional image 82 will continue to be highlighted until the position of the mitral valve is corrected. Therefore, after the operation of changing the position of the mark is completed, it is necessary for the user to take time to grasp which reference cross-sectional image the cross-sectional position changes with the change of the mark position in a certain reference cross-sectional image. Can be done. In addition, the reference cross-sectional images 82, 83, 85 to 87, 90, which are considered to have a high need to be continuously highlighted, such that the correction of the position of the mitral valve has not been completed, are continuously highlighted. Therefore, appropriate highlighting can be performed. Note that FIG. 11 is a diagram for explaining an example of processing executed by the display control unit 26d when the process returns to step S6 again in the first modification of the first embodiment.

Further, when the type of the feature portion whose position is indicated by the black-painted star-shaped mark whose position has been changed in the reference cross-sectional image 82 is the apex of the left ventricle, in step S6, the display control unit 26d sets the left ventricle. The reference cross-sectional images 81, 83, 85-87 whose cross-sectional position is defined by the position of the apex are highlighted in a display mode different from the display mode of the already highlighted reference cross-sectional images 82, 83, 85-87, 90. .. For example, as shown in FIG. 11, the display control unit 26d displays reference cross-sectional images 81, 83, 85 to 87 newly provided with a frame shown by diagonal lines. That is, in step S6, the display control unit 26d is a black-painted star in the reference cross-sectional image 82 highlighted in one of the reference cross-sectional images 82, 83, 85-87, 90 highlighted on the display unit 25. When the position of the type mark is changed, the type of the feature part whose position is indicated by the changed mark is painted black in which the position has already been changed in the reference section image 81 other than the reference section image 82. When the type of the feature portion whose position is indicated by the star-shaped mark is different from that of the feature portion, the cross-sectional position is defined by using the position of the feature portion whose position has been changed in the reference cross-sectional image 82. 87 is highlighted in comparison with the reference cross-sectional images 82, 84, 88-94 other than the reference cross-sectional images 81, 83, 85-87.

(Second variant of the first embodiment)
Further, in the first embodiment, the case where the MRI apparatus 100 highlights the reference cross-sectional image when a mark is designated and the position of the designated mark is changed in a certain reference cross-sectional image has been described. However, the MRI apparatus can also highlight a reference cross-sectional image when a mark is specified in a reference cross-sectional image. Therefore, such an embodiment will be described as a second modification of the first embodiment.

For example, in the second modification, the change unit 26c determines whether or not the user has specified the feature portion via the input unit 24. For example, when the pointer 24a is placed on the feature portion (or mark), the change portion 26c determines that the feature portion (or the feature portion whose position is indicated by the mark) is designated. Then, the changing unit 26c refers to the cross-sectional position definition information table 23a and specifies a reference cross-sectional image in which the cross-sectional position is defined by using the position of the designated feature portion.

Then, the display control unit 26d highlights the reference cross-sectional image specified by the changing unit 26c by comparing it with a reference cross-sectional image other than the specified reference cross-sectional image.

For example, in the example of FIG. 2 above, when the mitral valve of the left ventricular vertical long axis image 81 is designated, the changing portion 26c refers to the cross-sectional position definition information table 23a and specifies the designated mitral valve. Left ventricular horizontal long axis image 82, left ventricular short axis image 83, left ventricular four-chamber long-axis image 85, left ventricular two-chamber long-axis image 86, left ventricular three-chamber long axis Six reference cross-sectional images of image 87 and right ventricular four-chamber long-axis image 90 are identified. Then, as shown in FIG. 12, the display control unit 26d compares the specified six reference cross-sectional images with the reference cross-sectional images 81, 84, 88, 91 to 94 other than the specified six reference cross-sectional images. To highlight. Note that FIG. 12 is a diagram for explaining an example of processing executed by the MRI apparatus according to the second modification of the first embodiment. In this way, the display control unit 26d sets the reference cross-sectional image in which the cross-sectional position is defined by using the position of the designated feature portion before the position of the feature portion is changed, to the reference cross section other than the reference cross-sectional image. Highlight compared to the image. Therefore, according to the MRI apparatus according to the second modification, if the position of the characteristic portion is changed before the position of the characteristic portion is changed, the cross-sectional position of which reference cross-sectional image is changed. It is possible to let the user know whether or not to do so. Therefore, according to the MRI apparatus according to the second modification, the user can more easily position the reference cross-sectional image.

(Second embodiment)
Further, in the first embodiment, a case where the reference cross-sectional image to be highlighted is highlighted to the same degree has been described. However, the MRI apparatus can also highlight the reference cross-sectional image to be highlighted to a plurality of degrees. Therefore, such an embodiment will be described as a second embodiment.

In the second embodiment, for example, in the display control unit 26d, when the position of the feature portion is changed in a certain reference cross-sectional image, the cross-sectional position is defined by using the feature portion whose position has been changed. For other reference cross-sectional images, the magnitude of the change in cross-sectional position due to the change in the position of the feature portion is calculated.

For example, in the example of FIG. 2 above, the case where the user changes the position of the mitral valve of the left ventricular vertical long axis image 81 will be described. In this case, the display control unit 26d has a left ventricular horizontal major axis image 82, a left ventricular short axis image 83, a left ventricular four-chamber long axis image 85, and a left ventricle whose cross-sectional position is defined using the position of the mitral valve. For each of the six reference cross-sectional images of the left ventricular three-chamber long-axis image 86, the left ventricular three-chamber long-axis image 87, and the right ventricular four-chamber long-axis image 90, the magnitude of the change in the cross-sectional position due to the change in the position of the mitral valve. Is calculated.

Here, an example of a method of calculating the size of the cross-sectional position by changing the position of the mitral valve will be described for each of the six reference cross-sectional images. For example, the display control unit 26d calculates the angle between the movement vector of the mitral valve due to the change in position and the normal vector of each of the six reference cross-sectional images. The normal vector of each of the six reference cross-sectional images is calculated by the outer product of the two orthogonal unit vectors u and the unit vector v described above. Here, the closer the calculated angle is to 90 degrees, the smaller the magnitude of the change in the cross-sectional position due to the change in the position of the mitral valve. Therefore, when the calculated angle is (90-α) degrees or more and (90 + α) degrees or less, it is considered that the cross-sectional position does not change so much in the display control unit 26d. To highlight. On the other hand, when the calculated angle is less than (90-α) degrees or larger than (90 + α) degrees, the display control unit 26d is considered to have a large change in the cross-sectional position, and therefore has a predetermined strong degree. Highlight the reference section image with.

FIG. 13 is a diagram for explaining an example of processing executed by the MRI apparatus according to the second embodiment. For example, the display control unit 26d shows the reference cross-sectional images 82, 83, 85, 87, 90 whose calculated angle is less than (90-α) degrees or larger than (90 + α) degrees in the example of FIG. As described above, highlighting is performed so that the thickness of the frame becomes the first predetermined value. The user can set any value for α. Further, as shown in the example of FIG. 13, the display control unit 26d has a frame thickness larger than the first predetermined value for the reference cross-sectional image 86 having (90-α) degrees or more and (90 + α) degrees or less. Highlight so that it is a small second predetermined value. The change in the degree of emphasis is not limited to this method, and for example, the degree of emphasis may be continuously changed by using the difference from the calculated angle of 90 degrees as a parameter. Alternatively, the highlighting color may be changed according to the degree. As described above, in the MRI apparatus according to the second embodiment, the display control unit 26d has a large change in the cross-sectional position with respect to another reference cross-sectional image in which the cross-sectional position is defined by using the feature portion whose position has been changed. Highlight the degree according to the degree. Therefore, according to the MRI apparatus according to the second embodiment, the user can easily grasp which reference cross-sectional image the cross-sectional position changes with the change of the position of the feature portion in a certain reference cross-sectional image. , The user can easily grasp the degree of change in the display of the reference cross section whose cross-sectional position changes. Therefore, according to the MRI apparatus according to the second embodiment, the user can more easily position the reference cross-sectional image.

(Third Embodiment)
The MRI apparatus can also determine the cross-sectional position of a reference cross-sectional image. That is, the MRI apparatus can prevent the cross-sectional position of a reference cross-sectional image from being changed regardless of the change in the feature portion of another reference cross-sectional image. As a result, by determining / excluding the reference cross-section position within the permissible range, the number of confirmed cross-sections due to the subsequent correction work can be reduced, which leads to a reduction in the burden on the operator. Therefore, such an embodiment will be described as a third embodiment.

In the MRI apparatus according to the third embodiment, when a plurality of reference cross-sectional images are displayed on the display unit 25 by the generation unit 26b or the like, the cross-sectional position of at least one reference cross-sectional image among the displayed plurality of reference cross-sectional images. An instruction to confirm is input from the user via the input unit 24. Then, the display control unit 26d highlights the reference cross-sectional image whose cross-sectional position is determined, which is indicated by the input instruction, in comparison with other reference cross-sectional images.

FIG. 14 is a diagram for explaining an example of processing executed by the MRI apparatus according to the third embodiment. For example, when the display control unit 26d receives an instruction to determine the cross-sectional position of the reference cross-sectional image 81, the display control unit 26d superimposes the image 24b showing the pin on the reference cross-sectional image 81 to display the reference cross-sectional image 81 on the reference cross-sectional image 82. Highlight in comparison with ~ 94. The highlighting method is not limited to the method of superimposing the image showing the pin on the reference cross-sectional image, and any highlighting method can be used. Further, for example, by arranging only the images showing the pins in a layout using a separate window or the like, it becomes easy to confirm the reference cross section whose position is fixed and the reference cross section whose position is not fixed, and the movement of the viewpoint is reduced. It is effective because it leads to the reduction of the burden on the window.

In addition, when the display control unit 26d changes the positions of characteristic parts such as the mitral valve and the apex of the left ventricle that define the cross-sectional position of the reference cross-sectional image 81 in the reference cross-sectional images 82 to 94 other than the reference cross-sectional image 81. Even so, the cross-sectional position of the reference cross-sectional image 81 is not changed. As described above, according to the MRI apparatus according to the third embodiment, the cross-sectional position of a certain reference cross-sectional image can be determined by the user. Therefore, according to the MRI apparatus according to the third embodiment, the user can more easily position the reference cross-sectional image.

(Other embodiments)
The embodiment is not limited to the first to third embodiments described above.

(Target part)
In the first to third embodiments described above, the "heart" has been described as an example of the target site, but the embodiment is not limited to this. For example, it can be similarly applied to the case of inspection of joints such as "brain", "shoulder" and "knee", internal organs other than the heart, and various target parts such as various circulatory organs.

For example, when the "knee" is the target site, the coronal cross section of the knee is set based on the positions of two feature points, which are the lateral condyle of the femur and the dorsal edge of the medial condyle. 15 to 17 are diagrams for explaining an example of how to set various reference cross sections when the “knee” is the target portion in the embodiment. For example, as shown in FIG. 15, a reference line connecting two feature points is set. Then, as shown in FIG. 16, a coronal cross section parallel to the reference line and parallel to the cephalopod direction is set.

A cross section along the anterior cruciate ligament is also set based on the reference line. For example, as shown in FIG. 17, the reference line is rotated 90 degrees around the head and foot axis, the reference axis is lined by an angle of about 15 degrees, and the cross section including the reference axis and parallel to the head and foot direction is used as the anterior cruciate ligament. Set as a cross section along.

(Cross line)
Further, in the first to third embodiments described above, the case where the reference cross-sectional image is highlighted when the feature portion is specified or the position of the feature portion is changed has been described. The embodiment is not limited to this. For example, the MRI apparatus can also highlight a reference cross-sectional image when an intersection is specified or the position of the intersection is changed.
It should be noted that the user can specify the feature part by designating the mark indicating the position of the feature part, or change the position of the feature part by changing the position of the mark indicating the position of the feature part. In addition, the intersection line can be specified by specifying the intersection line mark, and the position of the intersection line can be changed by changing the position of the intersection line mark.

For example, when the display control unit 26d specifies an intersection line in which the cross-sectional position of this reference cross-sectional image and the cross-sectional position of another reference cross-sectional image intersect in a certain reference cross-sectional image, the display control unit 26d displays another reference cross-sectional image. It is highlighted in comparison with other reference cross-sectional images other than the reference cross-sectional image. FIG. 18 is a diagram for explaining an example of highlighting a reference cross-sectional image when the intersection line according to the embodiment is designated.

As shown in the example of FIG. 18, the left ventricular vertical long axis image 81 displays two types, a long axis connecting the mitral valve and the left ventricular apex, and a crossing line between the left ventricular short axis image. If the position of the intersection of the long axis is corrected, the positions of the mitral valve and the apex of the left ventricle are corrected at the same time, and the related cross-sectional positions are changed. Further, when the intersection line with the left ventricular short axis image is corrected, the cross-sectional position of the left ventricular short axis image 83 is changed.

In the example of FIG. 18, when the intersection line of the left ventricular short axis image 83 on the left ventricular vertical long axis image 81 is specified, the left ventricular short axis image 83 is displayed on the other reference cross-sectional images 81, 82, 84 to 94. Highlight compared to. Therefore, it is possible for the user to easily grasp which reference cross-sectional image the cross-sectional position changes with the change of the position of the cross-sectional line in a certain reference cross-sectional image before actually changing the position of the cross-sectional image. Can be done. Therefore, the user can easily position the reference cross-sectional image.

Similarly, when the display control unit 26d changes the position of the intersection line where the cross-sectional position of this reference cross-sectional image and the cross-sectional position of another reference cross-sectional image intersect in a certain reference cross-sectional image, another The reference cross-sectional image can be highlighted by comparing with other reference cross-sectional images other than the reference cross-sectional image.

(Type of reference cross-sectional image)
Further, in the first to third embodiments described above, the case where the inspection in which the types of the reference cross-sectional images are the above-mentioned 14 types is assumed has been described, but the embodiment is not limited to this. .. The type of the reference cross-sectional image may be various other types.

According to the magnetic resonance imaging apparatus of at least one embodiment described above, the user can easily position the reference cross-sectional image.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

26b Generation unit 26d Display control unit 100 Magnetic resonance imaging device

Claims (16)

A plurality of characteristic parts of the target are detected from the three-dimensional data collected including the target, and the target is detected.
Based on the detected plurality of feature sites, a plurality of cross-sectional positions different from each other are calculated.
A mark associated with the cross-sectional position is superimposed on each of the plurality of cross-sectional images generated from the three-dimensional data based on the plurality of cross- sectional positions so that the entire mark is included in the cross-sectional image. And
When the operation of changing the position of the superimposed mark is accepted in the first cross-sectional image of the plurality of cross-sectional images, another cross-sectional image different from the first cross-sectional image included in the plurality of cross-sectional images. Of the cross-sectional images, the second cross-sectional image in which the cross-sectional position changes in response to the change in the position of the mark is highlighted.
Medical image processing method. The mark is an intersection
In the first cross-sectional image, when the operation of changing the position of the cross-sectional line is performed, the cross-sectional position of the other cross-sectional image changes in response to the change in the position of the cross-sectional line. Highlight the cross-section image of 2,
The medical image processing method according to claim 1. A plurality of characteristic parts of the target are detected from the three-dimensional data collected including the target, and the target is detected.
Based on the detected plurality of feature sites, a plurality of cross-sectional positions different from each other are calculated.
A mark associated with the feature portion is superimposed on each of the plurality of cross-sectional images generated from the three-dimensional data based on the plurality of cross-sectional positions so that the entire mark is included in the cross-sectional image. And
When the operation of changing the position of the superimposed mark is accepted in the first cross-sectional image of the plurality of cross-sectional images, another cross-sectional image different from the first cross-sectional image included in the plurality of cross-sectional images. Of the cross-sectional images, the second cross-sectional image in which the cross-sectional position changes in response to the change in the position of the mark is highlighted.
Medical image processing method. The mark is information indicating the position of the feature portion for defining the cross-sectional position, and each feature portion has a different shape.
The medical image processing method according to claim 3. The subject is the heart
The cross-sectional image is at least one of a short-axis image, a horizontal long-axis image, a vertical long-axis image, a two-chamber image, a three-chamber image, and a four-chamber image.
The medical image processing method according to any one of claims 1 to 4. The subject is the heart
The cross-sectional image is at least one of an outflow path image and a valve image.
The medical image processing method according to any one of claims 1 to 4. The subject is the heart
The characteristic site is at least one of the position of the valve, the position of the apex, the position of the center of the ventricle, and the position of the outflow tract.
The medical image processing method according to any one of claims 1 to 6. The plurality of cross-sectional positions are selected by applying a slice-selective gradient magnetic field.
The medical image processing method according to any one of claims 1 to 7. The featured part is detected using machine learning,
The medical image processing method according to any one of claims 1 to 8. The featured part is detected by template matching.
The medical image processing method according to any one of claims 1 to 8. Further including a step of accepting the designation of the characteristic part from the operator,
The result specified by the operator is used to detect a plurality of feature parts of the target from the three-dimensional data collected including the target.
The medical image processing method according to any one of claims 1 to 8. The three-dimensional data is a plurality of slice images collected by a 2D sequence.
The medical image processing method according to any one of claims 1 to 11. The three-dimensional data is volume data collected by a 3D sequence.
The medical image processing method according to any one of claims 1 to 11. Based on the detected combination of the plurality of feature sites and the pre-stored combination of the cross-sectional positions and the feature sites, the plurality of cross-sectional positions different from each other are calculated.
The medical image processing method according to any one of claims 1 to 13. A detection unit that detects a plurality of feature parts of the target from three-dimensional data collected including the target and calculates a plurality of different cross-sectional positions based on the detected plurality of feature parts.
A mark associated with the cross-sectional position is superimposed on each of the plurality of cross-sectional images generated from the three-dimensional data based on the plurality of cross- sectional positions so that the entire mark is included in the cross-sectional image. Display section and
When the operation of changing the position of the superimposed mark is accepted in the first cross-sectional image of the plurality of cross-sectional images, another cross-sectional image different from the first cross-sectional image included in the plurality of cross-sectional images. Of the cross-sectional images, a control unit that highlights a second cross-sectional image whose cross-sectional position changes in response to a change in the position of the mark on the display unit.
A magnetic resonance imaging device comprising. A detection unit that detects a plurality of feature parts of the target from three-dimensional data collected including the target and calculates a plurality of different cross-sectional positions based on the detected plurality of feature parts.
A mark associated with the feature portion is superimposed on each of the plurality of cross-sectional images generated from the three-dimensional data based on the plurality of cross-sectional positions so that the entire mark is included in the cross-sectional image. Display section and
When the operation of changing the position of the superimposed mark is accepted in the first cross-sectional image of the plurality of cross-sectional images, another cross-sectional image different from the first cross-sectional image included in the plurality of cross-sectional images. Of the cross-sectional images, a control unit that highlights a second cross-sectional image whose cross-sectional position changes in response to a change in the position of the mark on the display unit.
A magnetic resonance imaging device comprising.

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