JP5484998B2 - Medical image processing apparatus and control program for fat region measurement - Google Patents

Description

  The present invention relates to a medical image processing apparatus and a fat area measurement control program, and more particularly to a medical image processing apparatus and a fat area measurement control program capable of measuring the thickness of adipose tissue existing around a coronary artery.

  Medical image diagnosis has made rapid progress with X-ray CT apparatuses, MRI apparatuses, and the like that have been put into practical use with the recent development of computer technology, and is indispensable in today's medical care. In particular, in X-ray CT apparatuses and MRI apparatuses, real-time display of image data becomes possible with the increase in the speed and performance of biological information detection apparatuses and arithmetic processing apparatuses, and further, generation of three-dimensional image data and Display is now easier.

  For example, in an X-ray CT apparatus, an X-ray tube that irradiates a subject with X-rays and an X-ray detector that detects X-rays transmitted through the subject are rotated around the subject. Projection data in a plurality of slice sections is collected by moving the subject in the body axis direction (slice direction). Then, three-dimensional data (hereinafter referred to as volume data) is generated by reconstructing these projection data. In addition, volume data can be collected by a helical method that collects projection data while moving the subject continuously in the body axis direction or a multi-slice method that uses an X-ray detector in which a plurality of detection elements are arranged in the body axis direction. The time required is further shortened.

  By the way, in a recent pathological study in the heart region, a new theory that adipose tissue formed around a coronary artery which is a nutritional blood vessel of the heart increases the risk of myocardial infarction has attracted attention. According to this theory, the coronary artery is continuously exposed to the inflammatory cytokines (inflammatory proteins) produced from the adipose tissue described above, thereby causing the progression of atherosclerosis (the progression of calcified plaque in the inner wall of the coronary artery). Generation) is considered to be accelerated (see Non-Patent Document 1, for example).

  In order to noninvasively observe the degree of adipose tissue formed along the outer boundary surface of the myocardial tissue, volume data collected by the above-described medical image diagnostic apparatus such as an X-ray CT apparatus or an MRI apparatus, or Predetermined threshold values for the three-dimensional image data obtained by rendering the volume data (for example, minimum threshold value −140 HU and maximum threshold value for volume data and three-dimensional image data collected by an X-ray CT apparatus) 40HU) has been set to extract a fat tissue region and display the obtained region in a single color with a predetermined color tone (see, for example, Patent Document 1).

JP 2003-061949 A

Ding Jingzhong et.al., "The Association of Pericardial Fat With Calcified Coronary Plaque", Obesity, Vol.16, No.8, 1914-1919 (2008)

  According to the above-described method, since the area of fat tissue (adipose area) existing around the coronary artery is displayed with a color tone different from that of other biological tissues such as myocardial tissue, the distribution state can be easily observed. . However, based on the theory that inflammatory proteins produced from adipose tissue act on the coronary arteries to develop atherosclerosis, how much fat tissue is accumulated around the coronary arteries It is important to grasp quantitatively.

  That is, according to the conventional method for displaying adipose tissue in a single color different from other tissues, it is possible to qualitatively evaluate whether the adipose region exists around the coronary artery, However, it was difficult to quantitatively evaluate the thickness.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a medical image processing apparatus and fat region measurement capable of quantitatively grasping the thickness of a fat region existing around a coronary artery. Is to provide a control program.

  In order to solve the above problems, the medical image processing apparatus of the present invention according to claim 1 includes core data generation means for generating core data of a coronary artery based on volume data collected from a heart region of a subject, A fat region setting means for setting a fat tissue region formed around the coronary artery as a fat region based on the volume data in each of the core line orthogonal cross sections set at predetermined intervals with respect to the core wire data; Fat thickness measurement means for measuring the fat thickness of a fat region, fat thickness distribution data generation means for generating fat thickness distribution data based on the measurement result of the fat thickness measured at each of the core line orthogonal cross sections, and the fat And a display means for displaying the thickness distribution data.

  According to a thirteenth aspect of the present invention, there is provided a fat region measurement control program for a medical image processing apparatus that measures a fat region existing around a coronary artery based on volume data collected from a heart region of a subject. A core line data generation function for generating the core line data of the coronary artery based on the volume data, and the coronary artery based on the volume data in each of the core cross-sections set at predetermined intervals with respect to the core line data. A fat region setting function for setting a fat tissue region formed around as a fat region, a fat thickness measurement function for measuring the fat thickness of the fat region, and the fat thickness measured in each of the core-orthogonal cross-sections Fat thickness distribution data generation function for generating fat thickness distribution data based on the measurement result, and display function for displaying the fat thickness distribution data It is characterized in that to the row.

  According to the present invention, the thickness of a fat region existing around a coronary artery can be quantitatively grasped. Therefore, it is easy to grasp the calcified area and the scab-like plaque area that occur in the coronary artery, and it is possible to predict the future of plaque generation, so it is useful for determining the treatment policy and determining the necessity of treatment. Can be obtained.

1 is a block diagram illustrating an overall configuration of a medical image processing apparatus according to an embodiment of the present invention. The figure which shows the coordinate system of the core wire data which the core wire data generation part of the Example produces | generates. The figure which shows the core wire orthogonal cross section which a core wire orthogonal cross-section setting part sets with respect to the core wire data of the Example. The figure for demonstrating the fat thickness measurement which the fat thickness measurement part of the Example performs using a fat area | region centerline. The figure which shows the specific example of the display data produced | generated in the display part of the Example. The flowchart which shows the measurement procedure of the fat area | region in the Example. The figure which shows the region of interest for fat volume measurement set with respect to the fat thickness distribution data of the Example.

Embodiments of the present invention will be described below with reference to the drawings.

  In the medical image processing apparatus of the present embodiment described below, first, core data of a coronary artery is generated based on volume data collected from a heart region of a subject, and a plurality of core orthogonal cross sections perpendicular to the core data are defined. Set by interval. Next, a fat region is set by extracting voxels having a CT value (voxel value) within a predetermined range from the volume data existing in the cross section of the core wire, and a fat region center line is set for the fat region. To do. The fat in the normal direction is based on the intersection position information of the plurality of normals perpendicular to the fat region center line set at predetermined intervals along the fat region center line and the outer boundary line and the inner boundary line of the fat region. The thickness (fat thickness) of the region is measured, and two-dimensional fat thickness distribution data is generated based on the measurement results of the fat thickness measured in a plurality of normal directions in each of the core line orthogonal cross sections.

  In this embodiment, the case where the thickness of the fat region existing around the coronary artery is measured based on the volume data collected by X-ray CT imaging of the subject to which the contrast medium has been administered will be described. For example, the measurement may be fat region measurement based on volume data collected by MRI imaging, ultrasonic imaging, or the like.

(Device configuration)
Hereinafter, the configuration and function of the medical image processing apparatus according to the present embodiment will be described with reference to FIGS.

  FIG. 1 is a block diagram illustrating the overall configuration of a medical image processing apparatus. A medical image processing apparatus 100 according to the present embodiment includes various types of devices that are supplied from an X-ray CT apparatus that is separately installed via a network (not shown). Volume data storage unit 1 that stores volume data, and a fat region measurement unit that measures the distribution and thickness of a fat region existing around a coronary artery based on the volume data, and generates two-dimensional fat thickness distribution data 2, an image data generation unit 3 that generates three-dimensional image data of a heart region including a coronary artery based on the volume data, and MPR image data of a fat region existing around the coronary artery, and an image data generation unit 3 A display unit 4 for displaying the three-dimensional image data and MPR image data generated by the user, the fat thickness distribution data generated by the fat region measuring unit 2, and the like Input unit 5 for inputting object information, setting a region of interest for fat thickness distribution data, setting a start point and an end point for a coronary artery region of three-dimensional image data, and inputting various command signals, etc. A system control unit 6 is provided that controls the unit in an integrated manner to execute fat region measurement and image data generation.

  The volume data storage unit 1 includes volume data collected by X-ray CT imaging of the subject's heart region to which a contrast medium is administered into the coronary artery and supplied via a network or a large-capacity storage medium. Are stored together with various volume data collected from the subject.

  On the other hand, as shown in FIG. 1, the fat region measurement unit 2 includes a core line data generation unit 21, a core line orthogonal cross section setting unit 22, a fat region setting unit 23, a fat region centerline setting unit 24, a fat thickness measuring unit 25, a fat A thickness distribution data generation unit 26, a fat volume measurement unit 27, and a C-MPR cross section formation unit 28 are provided.

  The core data generation unit 21 uses the start point set by the input unit 5 under observation of the three-dimensional image data for the coronary artery region of the volume data read from the volume data storage unit 1 as the starting point. Generates core data up to the end point set by. Various methods have already been proposed for generating the core data.

  For example, a plurality of unit vectors are generated in all three-dimensional directions with reference to the start point set by the input unit 5 for the coronary artery region of the three-dimensional image data generated by the image data generation unit 3 and displayed on the display unit 4 Then, the barycentric position of the blood vessel cross section orthogonal to the unit vector in the direction in which the distance from the unit vector to the inner wall of the blood vessel selected as the search vector is maximized is calculated.

  Next, a search vector whose direction is corrected so that the intersection position between the search vector and the blood vessel cross section coincides with the barycentric position is newly set in the barycentric position, and the search vector after correction is used to set the search vector described above. Core line data for the coronary artery is generated based on a plurality of barycentric positions in the blood vessel traveling direction obtained by repeating the procedure. The coronary artery region described above is set by extracting voxels having a CT value of [100 HU to 400 HU] corresponding to the CT value of the contrast medium from the volume data read from the volume data storage unit 1.

  FIG. 2 shows a coordinate system of the core line data Ca generated by the core line data generation unit 21 with respect to the volume data Va composed of a plurality of voxels arranged in three dimensions. It is generated by connecting the center of gravity Fq (Xq, Yq, Zq) in the transverse section of the blood vessel lumen with the coordinates F1 (X1, Y1, Z1) in the data Va as the start point and FQ (XQ, YQ, ZQ) as the end point. .

  Returning to FIG. 1, the core wire orthogonal section setting unit 22 of the fat region measurement unit 2 sets a plurality of reference points at predetermined intervals for the core data Ca generated in the coronary artery of the volume data by the core data generation unit 21. Then, the tangent direction with respect to the core data Ca is calculated at each reference point. A section perpendicular to the tangential direction (hereinafter referred to as a core line orthogonal section) is set for each of the reference points.

  FIG. 3 shows the core line data Ca generated by the core line data generation unit 21 for the coronary artery Vc of the volume data Va by the above-described method, and the core line orthogonal section setting unit 22 sets the core line data Ca at predetermined intervals. A tangential direction Tn (n = 1 to N) with respect to the reference point Pn (n = 1 to N) and the core line data Ca set at the reference point Pn, and a core line orthogonal section Dn (n = 1 to N) perpendicular to the tangential direction Tn. Is shown.

  Returning to FIG. 1 again, the fat region setting unit 23 of the fat region measuring unit 2 reads the volume data in the heart region of the subject stored in the volume data storage unit 1 and is set in the core orthogonal cross section setting unit 22. Core line orthogonal sections D1 to DN orthogonal to the core data Ca are set for the volume data. And the fat area | region in each core orthogonal cross section is set by extracting the voxel which has CT value of a predetermined range from the volume data which exist in the core orthogonal cross sections D1 thru | or DN.

  For example, for volume data collected by X-ray CT imaging, fat regions in the core orthogonal cross sections D1 to DN are set by extracting voxels having a preset CT value of [−140HU to −40HU]. Is done.

  On the other hand, the fat region centerline setting unit 24 is the center in the fat region thickness direction (that is, the direction substantially perpendicular to the outer boundary line of the myocardial tissue) set by the fat region setting unit 23 in the core line orthogonal cross sections D1 to DN. It has a function of setting a line (hereinafter referred to as a fat area center line), and includes, for example, a binarization processing unit and a thinning processing unit (not shown).

  The binarization processing unit binarizes voxels having a CT value of [−140 HU to −40 HU] constituting the fat region of the core line orthogonal cross sections D1 to DN set by the fat region setting unit 23, The thinning processing unit performs thinning processing on the binarized fat region voxels to set the fat region center line. Note that a method for setting a center line of an organ by applying thinning processing to medical image data is described in Japanese Patent Application Laid-Open No. 2009-195586 and the like, and thus detailed description thereof is omitted.

  Next, the fat thickness measurement unit 25 sets the fat region center line supplied from the fat region center line setting unit 24 to the fat regions of the core line orthogonal cross sections D1 to DN supplied from the fat region setting unit 23, and A plurality of normals perpendicular to the fat region center line are set at predetermined intervals along the fat region center line. Then, the thickness (fat thickness) of the fat region in the normal direction is measured based on the position coordinates of the intersection between the outer boundary line and the inner boundary line of the fat region and the normal line.

  FIG. 4 is a diagram for explaining fat thickness measurement performed by the fat thickness measurement unit 25 using the fat region center line, and includes the reference point Pn set by the core line orthogonal cross section setting unit 22 and is perpendicular to the core line data Ca. The cross section of the myocardial tissue Vb and the cross section of the coronary artery Vc are adjacent to each other in the core line orthogonal section Dn, and the fat region setting section 23 is [−140 HU to −40 HU] among the voxels existing in the core line orthogonal section Dn. A cross section of the fat region Af set by extracting voxels having CT values exists along the outer boundary line of the myocardial tissue Vb. Then, the fat region center line setting unit 24 detects the center in the thickness direction of the fat region Af along the outer boundary line of the myocardial tissue Vb by the above-described thinning process or the like, thereby setting the fat region center line Cx. Do.

  At this time, the fat thickness measurement unit 25 sets normal lines L1 to LM perpendicular to the above fat region center line Cx at predetermined intervals along the fat region center line Cx. Then, the position coordinates of the intersection Ram of the normal lines L1 to LM and the outer boundary line of the fat area Af and the intersection point Rbm of the inner boundary line are detected, and the fat area Af in the normal direction is detected based on these position coordinates. Measure the thickness (fat thickness).

  Next, the fat thickness distribution data generation unit 26 of the fat region measuring unit 2 shown in FIG. 1 outputs the thickness measurement result of the fat region Af with respect to the normals L1 to LM measured in each of the core line orthogonal sections D1 to DN as the core line. By arranging the data corresponding to the distance from the reference point Pn on the data, two-dimensional fat thickness distribution data centering on a linear coronary artery Vc as shown in FIG.

  On the other hand, when the fat volume measuring unit 27 sets the region of interest having a predetermined shape for the above-described fat thickness distribution data displayed on the display unit 4 together with the MPR image data generated by the image data generating unit 3 Then, the volume of the fat region Af in this region of interest is measured. Specifically, the fat volume in the region of interest can be measured by adding the fat thickness of the fat thickness distribution data surrounded by the region of interest.

  The C-MPR cross section forming unit 28 has an interpolation processing function (not shown), and the fat region center line setting unit 24 sets N fat region center lines Cx set for the fat regions Af in the core line orthogonal cross sections D1 to DN. A curved C-MPR (Curved-Multi Planar Reconstruction) cross section along the outer boundary surface of the myocardial tissue Vb is formed by performing interpolation processing with respect to the core line direction.

  Next, the image data generation unit 3 includes an MPR image data generation unit 31 and a three-dimensional image data generation unit 32. In the MPR image data generation unit 31, the C-MPR cross-section formation unit 28 of the fat region measurement unit 2 is a myocardium. A curved C-MPR cross section formed along the outer boundary surface of the tissue Vb is set for the volume data of the subject read from the volume data storage unit 1, and the volume data existing in the C-MPR cross section is set. MPR image data indicating the center of the fat region Af is generated by extracting the voxels. At this time, the above-described extracted voxels are arranged in correspondence with the distance from the core data Ca, thereby generating MPR image data in which a substantially linear coronary artery Vc is shown in the central portion (described later). (See 5 (a).)

  On the other hand, the three-dimensional image data generation unit 32 includes a coronary artery region setting unit, a volume data correction unit, an opacity / color tone setting unit, and a rendering processing unit (not shown). The coronary artery region setting unit, based on the CT value range for coronary artery region setting supplied from the system control unit 6, selects the contrast agent CT from the volume data of the subject supplied from the volume data storage unit 1. A coronary artery region is set by extracting voxels having a CT value of [100 HU to 400 HU] corresponding to the value.

  The volume data correction unit is configured to calculate a CT value of the coronary artery region set by the coronary artery region setting unit based on an inner product value of a preset line-of-sight vector for 3D display and a normal vector with respect to an organ boundary surface. to correct. On the other hand, the opacity / color tone setting unit sets opacity and color tone based on the corrected CT value, and the rendering processing unit is based on the opacity and color tone set by the opacity / color tone setting unit. Thus, the above-described voxel is rendered to generate 3D image data.

  The display unit 4 includes three-dimensional image data and MPR image data generated by the image data generation unit 3, fat thickness distribution data generated by the fat thickness distribution data generation unit 26 of the fat region measurement unit 2, and a fat volume measurement unit. 27 has a function of displaying the measurement result of the fat volume and the like, and includes a display data generation unit, a conversion processing unit, and a monitor (not shown).

  The display data generation unit includes a fat region central portion generated by the MPR image data generation unit 31 of the image data generation unit 3 based on the C-MPR cross section formed by the C-MPR cross section setting unit 28 of the fat region measurement unit 2. The fat thickness distribution data corresponding to the C-MPR cross section generated by the fat thickness distribution data generation unit 26 is superimposed on the MPR image data, and the measurement result of the fat volume in the predetermined region of interest measured by the fat volume measurement unit 27 is obtained. In addition, display data is generated.

  On the other hand, the conversion processing unit performs conversion processing such as D / A conversion and television format conversion on the display data generated by the display data generation unit and displays the display data on the monitor. The conversion processing unit also applies the same conversion process to the 3D image data generated by the 3D image data generation unit 32 of the image data generation unit 3 for the purpose of setting the start point and the end point in generating the core data Ca. To display on the monitor.

  FIG. 5 shows a specific example of the display data generated by the display data generation unit of the display unit 4. The vertical axis corresponds to the core line direction, and the horizontal axis corresponds to the fat region center line direction.

  FIG. 5A shows the subject in which the MPR image data generation unit 31 of the image data generation unit 3 reads out the C-MPR section formed along the outer boundary surface of the myocardial tissue Vb from the volume data storage unit 1. MPR image data IM of the peripheral part of the heart including the fat region Af generated by setting to the volume data of the Vxel extracted by the setting of the C-MPR cross section for the volume data at the distance from the core line data Ca is shown. By arranging them in correspondence with each other, MPR image data IM in which the coronary artery Vc is shown in a substantially straight line at the center thereof is generated.

  On the other hand, FIG. 5B shows the fat thickness distribution data IF generated by the fat thickness distribution data generating unit 26 of the fat region measuring unit 2 by the display data generating unit of the display unit 4 in the MPR image of FIG. This is display data generated by superimposing on the data IM, and the fat thickness distribution data IF is also arranged in correspondence with the distance from the core data Ca in the same manner as the MPR image data described above. Has been generated. Accordingly, the MPR image data IM and the fat thickness distribution data IF as shown in FIG. 5B can be superimposed, and a substantially straight coronary artery Vc is shown at the center.

  Then, a color tone corresponding to the measurement value of fat thickness is set for the fat thickness distribution data IF displayed superimposed on the MPR image data IM, and a color scale Sc indicating the relationship between the color tone and the fat thickness is displayed in the MPR image data. Added to the end of IM. As a specific example of the color scale display, for example, a region where the fat thickness is 0 mm is transparent, a region where 0 mm <fat thickness <20 mm is blue to red, and a region where the fat thickness is 20 mm or more is displayed in red. Although it is suitable, it is not particularly limited.

  Next, the input unit 5 shown in FIG. 1 is an interactive interface including an input device such as a keyboard, various switches, a selection button, a mouse, and a display panel, and inputs subject information, a starting point for a coronary artery region, End point setting, CT value range setting for coronary artery region and fat region, region of interest setting for fat thickness distribution data, image data generation condition and image data display condition setting, input of various command signals, etc. Do.

  On the other hand, the system control unit 6 includes a CPU and a storage circuit (not shown), and the above-described various information input or set in the input unit 5 is stored in the storage circuit. Then, the CPU comprehensively controls each unit of the medical image processing apparatus 100 based on the above-described input information and setting information, and measures the thickness of the fat region existing around the coronary artery and the fat based on the measurement result. Generate thickness distribution data, measure fat volume, etc.

(Fat area measurement procedure)
Next, the procedure for measuring the fat region in the present embodiment will be described with reference to the flowchart of FIG.

  Prior to the measurement of the fat region using the volume data of the subject, the operator of the medical image processing apparatus 100 inputs the subject information at the input unit 5 and then generates and displays the three-dimensional image data and MPR image data. And a CT value range [100HU to 400HU] for setting a coronary artery region administered with a contrast medium for volume data and a CT value for setting a fat area Af for the volume data Set the range [-140HU to -40HU]. These input information and setting information are stored in the storage circuit of the system control unit 6.

  When the above-described initial setting for the medical image processing apparatus 100 is completed, the operator inputs a fat region measurement start command at the input unit 5. On the other hand, the three-dimensional image data generation unit 32 of the image data generation unit 3 stores volume data corresponding to the subject information of the subject supplied from the system control unit 6 together with the above-described command signal in the volume data storage unit 1 in advance. A CT value of [100 HU to 400 HU] is read out from the volume data based on the CT value range for coronary artery region setting supplied from the system control unit 6 in the same manner as read out from various stored volume data. Extract the voxels you have. Then, rendering processing is performed on the obtained voxels to generate three-dimensional image data of the coronary artery Vc and display it on the monitor of the display unit 4 (step S1 in FIG. 6).

  Next, the operator who has observed the above-described three-dimensional image data displayed on the display unit 4 sets a start point and an end point for generating the core data Ca for the coronary artery Vc indicated in the three-dimensional image data. Set. Then, the position information of the start point and the end point set in the three-dimensional image data of the coronary artery Vc is supplied to the core data generation unit 21 of the fat region measurement unit 2 via the system control unit 6.

  The core data generation unit 21 extracts volume data by extracting voxels having a CT value of [100HU to 400HU] from the volume data read from the volume data storage unit 1 by the same procedure as the 3D image data generation unit 32. And the start point and end point are set for the coronary artery region based on the position information of the start point and end point supplied from the system control unit 6. Then, the core line data Ca for the coronary artery Vc is generated by performing the tracking process described above with the start point as a reference until the end point is reached (step S2 in FIG. 6).

  When the generation of the core wire data Ca by the core wire data generation unit 21 is completed, the core wire orthogonal cross section setting unit 22 sets a plurality of reference points Pn (n = 1 to N) at predetermined intervals for the core wire data Ca, and the reference A tangential direction Tn (n = 1 to N) with respect to the core data Ca is detected at each point Pn. Then, a core line orthogonal cross section Dn (n = 1 to N) perpendicular to the tangential direction Tn is set with respect to the reference point Pn (step S3 in FIG. 6).

  Next, the fat region setting unit 23 reads the volume data of the subject stored in the volume data storage unit 1 and sets the core wire orthogonal section Dn orthogonal to the core line data Ca set in the core line orthogonal section setting unit 22 to the core data orthogonal section Dn. Set for volume data. Then, based on the CT value range for fat region extraction supplied from the system control unit 6, voxels having a CT value of [−140 HU to −40 HU] are extracted from the voxels existing in the core line orthogonal section Dn. A fat region Af in the core line orthogonal cross section Dn is set (step S4 in FIG. 6).

  Next, the fat region centerline setting unit 24 indicates the center in the thickness direction of the fat region Af set by the fat region setting unit 23 in the core line orthogonal cross section Dn (direction substantially perpendicular to the outer boundary surface of the myocardial tissue Vb). The fat area center line Cx is set by applying a thinning method or the like (step S5 in FIG. 6).

  On the other hand, the fat thickness measurement unit 25 sets the fat region center line Cx supplied from the fat region center line setting unit 24 to the fat region Af of the core line orthogonal section Dn supplied from the fat region setting unit 23, and further A plurality of normals Lm (m = 1 to M) perpendicular to the region center line Cx are set at predetermined intervals along the fat region center line Cx. Then, the thickness of the fat region Af in the normal direction is measured based on the position coordinates of the intersection of the outer boundary line and the inner boundary line of the fat region Af and the normal line Lm (step S6 in FIG. 6).

  Next, the fat thickness distribution data generation unit 26 arranges the measurement result of the thickness (fat thickness) of the fat region Af measured in each of the core line orthogonal cross sections Dn in correspondence with the distance from the reference point Pn of the core line data Ca. Thus, two-dimensional fat thickness distribution data based on the coronary artery Vc is generated (step S7 in FIG. 6).

  On the other hand, the C-MPR section setting unit 28 performs a curved surface shape by interpolating the fat region center line Cx set by the fat region center line setting unit 24 for the fat region Af in the core line orthogonal section Dn with respect to the core line direction. The C-MPR cross section is formed (step S8 in FIG. 6).

  Then, the MPR image data generation unit 31 of the image data generation unit 3 uses the curved C-MPR cross section set by the C-MPR cross section formation unit 28 of the fat region measurement unit 2 along the outer boundary surface of the myocardial tissue Vb. MPR indicating the central part of the fat region Af and the coronary artery Vc by setting the volume data of the subject read from the volume data storage unit 1 and extracting the voxels of the volume data existing in the C-MPR section. Generate image data. In this case as well, as in the case of the fat thickness distribution data described above, each voxel is arranged in correspondence with the distance from the core data Ca, so that the coronary artery Vc is used as a reference (that is, a straight coronary artery). MPR image data (in which the artery Vc is shown in the center) is generated (step S9 in FIG. 6).

  Next, the display unit 4 displays MPR image data based on the coronary artery Vc generated by the MPR image data generation unit 31 of the image data generation unit 3 based on the C-MPR section formed by the C-MPR section setting unit 28. The fat thickness distribution data corresponding to the C-MPR section generated by the fat thickness distribution data generation unit 26 is superimposed on the display to generate display data and display it on its own monitor (step S10 in FIG. 6).

  On the other hand, the operator who observed the MPR image data on which the fat thickness distribution data is superimposed on the display unit 4 uses the input unit 5 to set a region of interest having a predetermined shape at a desired portion of the fat thickness distribution data (FIG. 6). Step S11), the fat volume measuring unit 27 of the fat region measuring unit 2 that has received the position information of the region of interest supplied from the input unit 5 via the system control unit 6 supplies from the fat thickness distribution data generating unit 26. The above-mentioned region of interest is set in the obtained fat thickness distribution data, and the fat volume is measured by adding the fat thickness of the fat thickness distribution data included in this region of interest. Then, the display unit 4 adds the measured value of the fat volume to the display data generated by superimposing the fat thickness distribution data on the MPR image data in the above-described step S10 and displays it on its own monitor (step of FIG. 6). S12).

  FIG. 7 shows a rectangular region of interest Ro set by the input unit 5 for display data generated by superimposing fat thickness distribution data on MPR image data, and the fat volume measuring unit 27 measures the region of interest Ro. The measurement result of the fat volume is added to the display data together with the region of interest Ro and displayed on the display unit 4.

  According to the embodiments of the present invention described above, the thickness of the fat region existing around the coronary artery can be quantitatively grasped. Therefore, it is easy to grasp the calcified area and the scab-like plaque area that occur in the coronary artery, and it is possible to predict the future of plaque generation, so it is useful for determining the treatment policy and determining the necessity of treatment. Can be obtained.

  In particular, according to the above-described embodiment, two-dimensional fat thickness distribution data along the outer boundary surface of the myocardial tissue can be obtained based on the measurement results of fat thickness measured at a plurality of sites. Since the fat thickness distribution data is displayed on a color scale according to the color tone corresponding to the value of the fat thickness, it is possible to grasp the accurate thickness of the fat region distributed around the coronary artery in a short time.

  Also, by setting the region of interest for the desired region of the fat thickness distribution data, the fat volume in the region of interest can be easily measured, and the curved shape formed along the center of the fat tissue By superimposing and displaying the fat thickness distribution data on the MPR image data in the MPR cross section, the state of the coronary artery and other living tissue existing around the fat region can be observed simultaneously.

  Furthermore, since the fat thickness distribution data and the MPR image data described above are generated based on the core data set for the coronary artery, the coronary artery expanded linearly and the fat thickness distribution corresponding to the coronary artery Can be observed.

  For the above reasons, according to the above-described embodiment, the accuracy and efficiency of examination / diagnosis for the subject can be greatly improved.

  As mentioned above, although the Example of this invention has been described, this invention is not limited to the above-mentioned Example, It can change and implement. For example, in the above-described embodiment, the case where the thickness of the fat region existing around the coronary artery is measured based on the volume data collected by the X-ray CT imaging of the subject to which the contrast medium is administered has been described. For example, the measurement may be fat region measurement based on volume data collected by MRI imaging, ultrasonic imaging, or the like. However, it is not always necessary to administer a contrast medium in MRI imaging or ultrasonic imaging.

  In the above-described embodiment, the case where fat region measurement is performed based on volume data supplied from a separately installed X-ray CT apparatus via a network or a storage medium has been described. The image may be directly supplied from a medical image diagnostic apparatus such as an apparatus, and the medical image processing apparatus 100 may be a part of the medical image diagnostic apparatus.

  Furthermore, when the fat thickness distribution data is displayed superimposed on the MPR image data, the case where the fat thickness distribution data is displayed in a color scale has been described, but a gray scale display having a luminance corresponding to the measured value of the fat thickness is performed. Also good. Further, although the case where the fat thickness distribution data and the fat volume measurement result are displayed superimposed on the MPR image data has been described, the fat thickness distribution data and the fat volume measurement result may be displayed independently.

  On the other hand, in the above-described embodiment, the case where the core line data of the coronary artery is generated by the tracking method using the search vector has been described. However, the present invention is not limited to this. The core data may be generated by thinning processing. In addition, a method other than the thinning process may be applied to generate the fat region center line.

  Furthermore, in the above-described embodiment, the fat thicknesses measured in each of the cross-sections of the core wire are arranged in correspondence with the distance from the reference point of the core data, so that the fat centered on the straight coronary artery Although the case of generating the thickness distribution data has been described, the volume data obtained from the subject is reconstructed into straight volume data so that the core data becomes a straight line, and the fat thickness distribution data is based on the straight volume data. May be generated. Also in this case, it is possible to generate fat thickness distribution data centered on the linearly expanded coronary artery similar to FIG.

  The function of each unit of the adipose tissue measuring unit 2 described above is achieved by, for example, using a general-purpose computer device as basic hardware and installing a dedicated image processing program or measurement program in the basic hardware. In such a case, the adipose tissue measuring unit 2 in FIG. 1 shows a functional block diagram.

DESCRIPTION OF SYMBOLS 1 ... Volume data storage part 2 ... Fat area | region measurement part 21 ... Core wire data generation part 22 ... Core wire orthogonal cross-section setting part 23 ... Fat area | region setting part 24 ... Fat area | region center line setting part 25 ... Fat thickness measurement part 26 ... Fat thickness distribution Data generating unit 27 ... Fat volume measuring unit 28 ... C-MPR cross section forming unit 3 ... Image data generating unit 31 ... MPR image data generating unit 32 ... 3D image data generating unit 4 ... Display unit 5 ... Input unit 6 ... System control Unit 100 ... medical image processing apparatus

Claims (13)

Core data generating means for generating coronary artery core data based on volume data collected from the heart region of the subject;
A fat region setting means for setting a fat tissue region formed around the coronary artery based on the volume data in each of the core line orthogonal cross sections set at predetermined intervals with respect to the core data as fat regions;
A fat thickness measuring means for measuring the fat thickness of the fat region;
A fat thickness distribution data generating means for generating fat thickness distribution data based on the measurement result of the fat thickness measured in each of the core line orthogonal cross sections;
A medical image processing apparatus comprising: display means for displaying the fat thickness distribution data.   The medical image processing apparatus according to claim 1, wherein the core line data generation unit generates the core line data by performing tracking processing or thinning processing on a coronary artery region of the volume data.   The fat region setting means sets the fat region by extracting voxels having a predetermined range of voxel values from voxels existing in the core line orthogonal section of the volume data. Medical image processing apparatus.   A fat region center line setting unit that sets a center line in the fat region as a fat region center line is provided, and the fat thickness measuring unit measures the fat thickness of the fat region in a normal direction perpendicular to the fat region center line. The medical image processing apparatus according to claim 1, wherein:   The fat thickness measuring unit sets a plurality of normals at predetermined intervals with respect to the fat region center line, and is based on intersection position information between each of the normals and the outer boundary line and the inner boundary line of the fat region. The medical image processing apparatus according to claim 4, wherein the fat thickness in the normal direction is measured.   The fat thickness distribution data generation means arranges the fat thickness measurement results measured in a plurality of normal directions in each of the core line orthogonal sections in correspondence with the distance from the core line data, thereby arranging the fat thickness. The medical image processing apparatus according to claim 1, wherein distribution data is generated.   The fat region center line setting means forms a curved C-MPR (Curved-Multi Planar Reconstruction) section based on a plurality of fat region center lines set for the fat region in each of the core line orthogonal sections. C-MPR cross-section forming means, and MPR image data generating means for generating MPR image data by setting the C-MPR cross-section to the volume data, wherein the display means is generated by the fat thickness distribution data generating means The medical image processing apparatus according to claim 1, wherein the fat thickness distribution data thus displayed is superimposed on the MPR image data.   The C-MPR cross-section forming unit is configured such that the fat region center line setting unit interpolates the plurality of fat region center lines set in each of the core line orthogonal cross sections with respect to a core line direction. The medical image processing apparatus according to claim 6, wherein a cross section is formed.   The MPR image data generation means arranges the voxels of the volume data extracted in the C-MPR cross section corresponding to the distance from the core line data, so that the linear coronary artery is located at the center thereof. The medical image processing apparatus according to claim 6, wherein MPR image data is generated.   A region-of-interest setting unit that sets a region of interest having a predetermined shape with respect to the fat thickness distribution data, and a fat volume measuring unit that measures a fat volume in the fat region, wherein the fat volume measuring unit The medical image processing apparatus according to claim 1, wherein the fat volume is measured by adding the measurement results of the fat thickness in the region of interest set to 1.   2. The medical image processing apparatus according to claim 1, wherein the display means displays a color scale by setting a color tone corresponding to a measured value of fat thickness for the fat thickness distribution data.   2. The medical image processing apparatus according to claim 1, wherein the display unit displays a gray scale by setting a luminance corresponding to a measured value of fat thickness for the fat thickness distribution data. For a medical image processing apparatus that measures a fat region around a coronary artery based on volume data collected from a heart region of a subject,
A core data generation function for generating core data of the coronary artery based on the volume data;
A fat region setting function for setting a fat tissue region formed around the coronary artery as a fat region based on the volume data in each of the core line orthogonal cross sections set at predetermined intervals with respect to the core wire data;
A fat thickness measurement function for measuring the fat thickness of the fat region;
A fat thickness distribution data generation function for generating fat thickness distribution data based on the measurement result of the fat thickness measured in each of the cross sections perpendicular to the core line;
A fat region measurement control program for executing a display function for displaying the fat thickness distribution data.