JP5173050B2 - Medical image processing device - Google Patents

Description

  The present invention relates to a medical image processing apparatus, and more particularly to an improvement of an X-ray diagnostic treatment apparatus using information of an interventional radiology simulator.

  There is a CT (Computed Tomography) apparatus that collects X-ray projection images over 360 degrees around the human body and reconstructs them into a two-dimensional tomographic image. Recently, continuous tomographic images can be acquired in a short time by the techniques of multi-slice CT and helical CT, and a moving image of X-ray three-dimensional data has been obtained.

  In addition, the CT image is called a CT value, and the X-ray attenuation coefficient value is displayed as a standardized value such that water is 0, bone is 1000, and air is -1000. Each organization can be identified.

  In the clinical field, there is an increasing movement to introduce CT for examination of circulatory system such as myocardial infarction and cerebral infarction. The reason for this is that, in addition to being less invasive than catheter examinations using conventional cardiovascular devices, it is possible to determine the state of the blood vessel itself, such as plaque properties, using the CT value. There is.

  On the other hand, when stenosis or dangerous plaque is found by examination, catheter treatment (intervention) such as ballooning or stenting under fluoroscopy with an X-ray circulatory apparatus is common.

  An X-ray circulator is generally characterized by displaying a unidirectional projection image in real time while suppressing the exposure amount so that the catheter insertion process and the flow of contrast medium can be easily understood. Becomes a two-dimensional (2D) projection image instead of a three-dimensional (3D) image by the CT apparatus (see, for example, Patent Document 1 below). Therefore, since the 2D projection image is easier to compare as the image referred to during the intervention than the 3D image, it is important to convert the 3D image obtained by CT into 2D and display it.

  By the way, in the above-described prior art, when converting 3D data obtained by CT into a 2D projection image, it is not easy to determine the plaque position by simply converting it into a projection image and displaying it.

  In addition, information such as the amount of plaque in the projection direction and the plaque properties are lost.

JP 2006-320722 A

  An object of the present invention is to provide a medical image processing apparatus that facilitates determination of a plaque position and facilitates determination of a plaque amount and a plaque property in a projection direction when converting three-dimensional data into a two-dimensional projection image. It is to be.

  The medical image processing apparatus according to the present embodiment targets an extraction unit that extracts a contrast blood flow region and a plaque region based on a CT value range from three-dimensional CT data about the subject, and the contrast blood flow region and the plaque region. A blood vessel / plaque projection image generation unit for generating a blood vessel / plaque projection image as a color value is assigned to each pixel in a range corresponding to the plaque region on the blood vessel / plaque projection image, and the contrast blood flow region A determination unit for determining the position of the plaque region with respect to the contrast blood flow region on the near side / back side with respect to the projection direction, and a blood flow / plaque projection image. And a display unit that displays the image superimposed on the projected image.

1 is a block configuration diagram showing a basic configuration of a medical image processing apparatus according to a first embodiment of the present invention. It is a figure for demonstrating the display method of the plaque in 1st Embodiment. It is a flowchart for demonstrating operation | movement of the medical image processing apparatus 10 of 1st Embodiment. It is a figure for demonstrating the focus of an X-ray tube, the position of an X-ray detector, and a top plate. It is the figure shown about the example of extraction of the plaque in 1st Embodiment. It is a figure for demonstrating operation | movement by the medical image processing apparatus 10 of 1st Embodiment. It is a figure for demonstrating operation | movement by the medical image processing apparatus 10 of 1st Embodiment. It is a flowchart for demonstrating the operation | movement for obtaining an intervention reference image from the X-ray projection image by the 2nd Embodiment of this invention. It is the figure shown about the example of extraction of the plaque in 2nd Embodiment. (A) is the figure which showed the example of a stenosis rate image, (b) is the figure which showed the example of the image which displayed the blood-vessel centerline in color. It is a flowchart for demonstrating the operation | movement for obtaining an intervention reference image from the X-ray projection image by the 3rd Embodiment of this invention. It is the figure shown about the example of extraction of the plaque in 3rd Embodiment. It is the figure which showed the example of the stenosis rate image. It is the figure showing the example of the contrasted blood vessel (contrast blood vessel) 131 in the voxel 130 and its plaque 132. FIG. FIG. 15 is a cross-sectional view of the contrasted blood vessel 131 of FIG. 14. It is the figure which showed the example of the projection direction with respect to the voxel. It is the figure showing the example where the plaque 132 is located in front of the contrasted blood vessel. It is a figure showing the example which is located in the other side of the blood vessel in which the plaque 141 was contrasted. It is a figure showing the example in which the plaques 132 and 141 are located on both the near side and the far side of the contrasted blood vessel. It is the figure showing the other example which is located in front of the blood vessel in which the plaque 132 was contrasted. It is a figure for demonstrating the example in which a color image is produced | generated along a shadow direction. It is the figure which showed an example of the relationship between the projection direction with respect to the blood vessel, and a projection image. It is the figure which showed the other example of the relationship between the projection direction with respect to the blood vessel, and a projection image. It is the figure which showed the structure of the medical image processing apparatus which concerns on the 5th Embodiment of this invention. It is a block block diagram which shows an example of the detail of the medical image processing apparatus shown by FIG. It is the figure shown about the example of extraction of the plaque in 5th Embodiment. (A) is the figure which showed the example of the image of an X-ray circulatory apparatus, (b) is the figure which showed the example of the image of the medical image processing apparatus by 5th Embodiment. FIG. 10 is a first modification of the fifth embodiment, and is a diagram for explaining superposition of soft plaque images when a target blood vessel position such as a heart region moves in the alignment unit 18; It is a 2nd modification of 5th Embodiment, Comprising: It is a figure for demonstrating alignment. It is a 2nd modification of 5th Embodiment, Comprising: It is a figure for demonstrating image superimposition. It is a block block diagram which shows an example of the detail of the medical image processing apparatus which concerns on the 2nd modification of 5th Embodiment. It is a block block diagram which shows an example of the detail of the medical image processing apparatus which concerns on the 3rd modification of 5th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block configuration diagram showing a basic configuration of a medical image processing apparatus according to the first embodiment of the present invention.

  The medical image processing apparatus 10 according to the present embodiment includes a position input unit 11, a CT image input unit 13, an image extraction unit 14, a projection image creation unit 15, an image superimposition unit 16, and a monitor 17. And the system controller 18.

  Although not shown, the position input unit 11 is for operating the focus of X-rays irradiated from the X-ray tube of the circulatory device, the detector, the position of the top plate, etc., and inputting the position information. is there. The CT image input unit 13 inputs three-dimensional (3D) data from CT images collected in advance during the examination. The image extraction unit 14 acquires information about the three-dimensional position and the CT value at each position from the CT image input from the CT image input unit 13, and a desired image (an image of the plaque region) based on the CT value. ).

  The projection image creation unit 15 creates a projection image of the plaque based on the image obtained from the CT image input unit 13, the image extracted by the image extraction unit 14, and information input by the position input unit 11. To do. A method for creating the projection image of the plaque will be described later.

  The image superimposing unit 16 superimposes the plaque projection image created by the projection image creating unit on a normal CT image and displays it on the monitor 17. Further, the system controller 19 controls the overall control operation of the medical image processing apparatus 10.

  FIG. 2 is a diagram for explaining a plaque display method in the present embodiment.

Plural plaques 102 ₁ , 102 ₂ , 102 ₃ are formed on the tube wall of the blood vessel 100. The treatment is performed by inserting the catheter 101 into the blood vessel 100. However, in the conventional method, information such as the amount of plaque in the projection direction and the plaque symptom is lost when converting the projection image. Therefore, in the present invention, the display color can be identified according to the amount of plaque and the symptoms (for example, hard and soft).

  Next, the operation of the medical image processing apparatus 10 will be described with reference to the flowchart of FIG.

  FIG. 3A is a flowchart for explaining an operation for obtaining an intervention reference image from a normal X-ray projection image. FIG. 3B is a flowchart for obtaining an intervention reference image from the X-ray projection image according to this embodiment. It is a flowchart for demonstrating the operation | movement for.

  First, an operation for obtaining an intervention reference image from a normal X-ray projection image will be described with reference to the flowchart of FIG.

  In step S1, the CT image input unit 13 acquires information about a three-dimensional position and CT values (eigenvalues) at each position from a CT image collected in advance during the examination. This information is, for example, four pieces of information including an X coordinate, a Y coordinate, a Z coordinate, and a CT value. Subsequently, in step S2, the position input unit 11 inputs the focal point of the X-ray tube, the position information of the X-ray detector and the top plate on which the patient is placed. Then, in step S3, as shown in FIG. 4A, the three-dimensional positions of the focal point 21, the detection surface 23, and the subject (3D data) 22 of the X-ray tube (not shown) are changed to the system controller 19. Is calculated by

  Then, in the subsequent step S4, the value calculated in step S3 is imaged by the projection image creating unit 15. In step S5, it is displayed on the monitor 17 as an intervention reference image.

  Next, the operation for obtaining the intervention reference image from the X-ray projection image according to the present embodiment will be described with reference to the flowchart of FIG.

  In step S11, similarly to step S1 in the flowchart of FIG. 3A described above, the CT image input unit 13 obtains a CT value (eigenvalue at each position) and a three-dimensional position from the CT image previously collected at the time of examination. ) Information is acquired. For example, as shown in FIG. 5A, information on the blood vessel 100 and plaques 102a, 102b, or 102c formed on the vessel wall of the blood vessel 100 is acquired.

  Next, in step S12, only the region of plaques 102a, 102b, or 102c is extracted from the vessel wall of the blood vessel 100 as shown in FIG. For example, if the CT value is 0 to 50, it is extracted as a soft plaque, if it is 400 or more, it is extracted as a calcified plaque, and if it is between 50 and 400, it is extracted as a normal plaque. Of course, the CT value may be set more finely and the types of plaques may be divided.

  In step S13, the plaque region is classified based on the CT value, and the display color representing the property of the plaque when displayed on the monitor 17 is determined. For example, when the ratio of RGB is represented, as shown in FIG. 5 (c), the soft plaque (CT value; 0 to 50) described above is red, the calcified plaque (CT value; 400 or more) is blue, Plaque green, etc. Of course, a CT value may be set more finely and a plaque display color may be assigned. Further, instead of the display color, it may be expressed by a gradation ratio or the like.

  In subsequent step S14, as in step S2 in the flowchart of FIG. 3A described above, the position input unit 11 is used to input the focal point of the X-ray tube, the position information of the X-ray detector and the top plate on which the patient is placed. Is entered. Then, as shown in FIG. 4B, the three-dimensional positions of the focal point 21, the detection surface 23, and the subject (plaque region) 24 of the X-ray tube (not shown) are calculated.

  FIG. 6 is a diagram showing a state of actual X-ray diagnosis.

  A patient 25 is placed on a top plate (mounting table) 26, and an X-ray tube 27 and an X-ray detector 28 that are opposed to each other centering on the patient 25 are supported by a C arm 29. The positions of the plaques 102a and 102b in the blood vessel of the patient 25 are detected using the focal point 21 of the X-ray tube 27 as the origin of the X, Y, and Z coordinates.

  In step S15, as shown in FIG. 7A, the plaque region 102c existing on the X-ray path from the focal point 21 to the detection surface 23 corresponds to the integrated value integrated for each display color of the plaque region. The displayed density is determined. For example, an integrated value in each pixel is once obtained, and the density is determined as a percentage as a ratio to the maximum integrated value in the detection surface 23.

  In step S16, as shown in FIG. 7B, for each display color of the plaque regions 102a, 102b, and 102c assigned in step S13, the integrated value in the projection direction obtained in step S15 is calculated. A projection image reflected as the density is created.

  Next, in step S17, at this time, the background is the projection image created in step S4 in the flowchart of FIG. 3A described above, and the density is displayed as the transmittance of the overlay display with respect to the background. That is, if the density is 30%, the background is displayed at a ratio of 70% and the plaque area image is displayed at a ratio of 30%.

  After that, in step S18, it is displayed on the monitor 17 as an intervention reference image as shown in FIG.

  Note that the overlaid images may be arbitrarily switched at each stage, or all may be displayed together. In addition, neighboring objects may be displayed together as a coarser stage.

  As described above, according to the first embodiment, the position, amount, and property of the plaque can be accurately identified on the two-dimensional projection image.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  In the embodiment described below, the basic configuration of the medical image processing apparatus is the same as that of the first embodiment described above. A reference number is attached | subjected, the illustration and description are abbreviate | omitted, and only a different part is demonstrated.

  In the second embodiment, in accordance with the first embodiment described above, a place where stenosis occurs is displayed on the two-dimensional image so that it can be easily identified.

  FIG. 8 is a flowchart for explaining an operation for obtaining an intervention reference image from an X-ray projection image according to the second embodiment of the present invention.

  In step S21, as shown in FIG. 9A, the CT image input unit 13 acquires information about the three-dimensional position and the CT value (eigenvalue) at each position from the CT image. Next, in step S22, based on the CT value, as shown in FIG. 9B, the blood vessel lumen 110 and the plaque regions 102a and 102b are extracted separately.

  In step S23, the focal point of the X-ray tube, the position information of the X-ray detector and the top plate on which the patient is placed are input. Subsequently, in step S24, as shown in FIG. 9C, a projection image 111 of the blood vessel lumen on the detection surface is created. The blood vessel lumen 110 can be selected from the CT value of the contrast agent.

  Furthermore, in step S25, in order to identify the blood vessel traveling direction, as shown in FIG. 9D, the center line 113 of the image of the blood vessel lumen 110 is extracted by image processing. For this extraction, a general line center extraction method using image processing software or the like may be used. Next, in step S26, a perpendicular to the center line obtained in step S25 is defined as a cross-sectional line 114. The cross-sectional line 114 is the blood vessel lumen + the plaque width.

In step S27, a plane including the cross-sectional line on the projection plane and the X-ray focal point is defined. Here, as shown in FIG. 9 (e), the plaque region area and the blood vessel lumen area in the set plane are extracted from each CT value, and the stenosis rate is calculated from each area ratio as follows. The
Stenosis rate = plaque area / (plaque area + vessel lumen area)
In step S28, the color of the cross section line 114 is determined based on the stenosis rate calculated in step S27. Subsequently, in step S29, as shown in FIG. 9F, the cross-sectional lines 114 set at arbitrary intervals with respect to the center line 113 are displayed in the display color based on the stenosis rate. . Thereby, as shown in FIG. 10A, a stenosis rate image 118 is created. At this time, the interval between the cross-sectional lines may be set very finely to create a continuous stenosis image, or the stenosis rate and color may be determined by interpolation between the cross-sectional lines set coarsely.

  Thereafter, in step S30, the created stenosis image is displayed as an overlay on the projection image created in the flowchart of FIG.

  As a display method similar to the flowchart of FIG. 8, the blood vessel center line itself may be displayed in color as shown in FIG.

  According to the second embodiment, it is possible to easily determine stenosis on a two-dimensional image.

(Third embodiment)
Next, a third embodiment of the present invention will be described.

  In the third embodiment, in order to follow the second embodiment described above, a display method is employed in which the plaque property and the stenosis rate can be easily distinguished on a two-dimensional image.

  FIG. 11 is a flowchart for explaining an operation for obtaining an intervention reference image from an X-ray projection image according to the third embodiment of the present invention.

  In step S41, as shown in FIG. 12A, the CT image input unit 13 acquires information on a three-dimensional position and CT values (eigenvalues) at each position from the CT image. Next, in step S42, as shown in FIG. 12B, the blood vessel lumen 110 and the plaque regions 102a and 102b are extracted separately based on the CT value.

  In step S43, as shown in FIG. 12C, the display color based on the CT value is determined for the plaque regions 102a and 102b extracted in step S42. Next, in step S44, the focal point of the X-ray tube, the position information of the X-ray detector and the top plate on which the patient is placed are input, and in step S45, as shown in FIG. A projection image 111 of the blood vessel lumen is created.

  Further, in step S46, in order to identify the blood vessel traveling direction, the center line 113 of the image of the blood vessel lumen 110 is extracted by image processing as shown in FIG. For this extraction, a general line center extraction method using image processing software or the like may be used. Next, in step S47, a perpendicular to the center line obtained in step S46 is defined as the cross section line 114. The cross-sectional line 114 is the blood vessel lumen + the plaque width.

  In step S48, a plane including the section line on the projection plane and the X-ray focal point is defined. Here, as shown in FIG. 12 (f), the plaque region area and the blood vessel lumen area in the set plane are extracted from each CT value, and the stenosis rate is calculated from each area ratio from the above-described formula. The Next, in step S49, the display shape (length) of the cross-sectional line is determined based on the stenosis rate calculated in step S48. As the shape, the length of the line to be displayed from both ends is determined according to the ratio of the stenosis rate as shown in FIG. Further, the display color is the color determined in step S43 (see FIG. 13B). Conversely, a line may be extended from the center toward both ends of the blood vessel 120 (see FIG. 13C).

  In step S50, as shown in FIG. 12G, the cross-sectional lines 114 set at arbitrary intervals with respect to the center line 113 are displayed in the display color based on the stenosis rate. Thereby, a stenosis rate image is created. Further, a continuous narrowed image may be created by setting the interval between the cross-sectional lines very finely. Further, a stenosis image may be created by determining a stenosis rate by interpolation between cross-sectional lines set relatively coarsely.

  Thereafter, in step S51, the created stenosis image is displayed as an overlay on the projection image created in the flowchart of FIG. At this time, a stenosis image is created for each display color classified stepwise in step S43 so that a plaque property to be overlaid on the projection image can be selected as shown in FIG. 13 (d). good.

  According to the third embodiment, there is an effect that stenosis and properties can be easily discriminated on a two-dimensional image.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described.

  In general, an image such as an X-ray fluoroscopic image (pseudo fluoroscopic image) can be created from voxel data collected by a CT apparatus. In addition, plaque can be extracted from voxel data by threshold processing or the like. However, when displaying plaque distribution information or the like on the pseudo-transparent image, information in the depth direction is lost. Further, there is a limit in expressing information in the depth direction even in a volume rendering image or the like.

  Therefore, in the fourth embodiment, an attempt is made to express distribution information in the depth direction of the plaque by superimposing a color image on the pseudo-perspective image.

  Since the contrasted blood vessel has a very large CT value compared to the surrounding, it can be easily extracted from the voxel data by threshold processing or the like. In addition, since the plaque adheres in the blood vessel, the plaque can be extracted by performing threshold processing or the like only in the vicinity of the contrasted blood vessel described above.

  FIG. 14 is a diagram showing an example of a contrasted blood vessel (contrast blood vessel) 131 and its plaque 132 in a certain voxel 130. FIG. 15 is a cross-sectional view of the contrasted blood vessel 131 of FIG. The plaque search range 136 is within a predetermined radius from the center of gravity 135 in the cross section of the contrasted blood vessel 131. Reference numeral 134 denotes an inner wall of the blood vessel.

  Then, as shown in FIG. 16, the (pseudo) fluoroscopic image (black and white image) of the contrast blood vessel 131 is projected on the projection plane 138 by designating the voxel 130 with the illustrated arrow direction as the projection direction. A blood vessel image 139 can be generated. During such projection, the positional relationship between the contrasted blood vessel 131 and the plaque 132 can be classified as shown in FIGS.

  That is, FIG. 17 shows an example in which the plaque 132 is positioned in front of the blood vessel on which the contrast is contrasted. FIG. 18 shows an example in which the plaque 141 is located on the other side of the blood vessel on which the contrast is contrasted. Further, FIG. 19 shows an example in which plaques 132 and 141 are located both in front of and behind the contrasted blood vessel. In the case of the example shown in FIG. 20, the plaque 142 is classified as being located in front of the contrasted blood vessel, as in FIG.

  For such a plaque, as shown in FIG. 21, a color image is generated along the projection direction and displayed superimposed on the above-described black and white image. At this time, the plaque 132 located in front of the contrasted blood vessel is assigned to red (R), for example, and the plaque 141 located on the other side of the contrasted blood vessel is assigned to, for example, blue (B) to form an image. Further, the thickness of the plaque along the projection direction or the integrated value of the voxel values is made to correspond to the luminance of each color component.

  For example, as shown in FIG. 22 (a), the direction indicated by the arrow in FIG. Then, as shown in FIG. 22B, the plaque 132 positioned in front of the blood vessel is displayed in red as a projection image as shown in FIG. Further, as shown in FIG. 22 (c), the plaque 141 located on the other side of the blood vessel is displayed in blue as a projection image as shown in FIG. 22 (f). Furthermore, as shown in FIG. 22 (d), when both the plaque 132 located in front of the blood vessel and the plaque 141 located on the far side exist, as a projection image as shown in FIG. 22 (g). Is displayed in purple.

  As shown in FIG. 19, when the plaques 132 and 141 are located on both sides of the contrasted blood vessel, they are imaged in purple.

  Furthermore, the color superimposed image described above changes as shown in FIG. 23 by changing the projection direction.

  For example, if plaques 142 and 143 are present at the positions shown in FIG. 23B with respect to the contrasted blood vessel 145 shown in FIG. As shown in FIG. 23 (d), it is represented by colors (red, blue) corresponding to the positions of the plaques 142 and 143, respectively. On the other hand, if the projection direction is 2, the projected image is expressed in purple as shown in FIG.

  In this way, the three-dimensional positional relationship between the plaque and the contrasted blood vessel can be easily depicted.

  The correspondence between the plaque and color image components as shown in FIG. 21 is such that all the plaque thicknesses, X-ray attenuation rate integral values, or maximum values correspond to the luminance of the green (G) component. Also good.

  Next, a modification of the fourth embodiment will be described.

  In the above-described fourth embodiment, the positional relationship of the plaque with respect to the contrasted blood vessel is displayed by color. However, as a modified example 1, the above-described positional relationship is ignored and the total plaque thickness or voxel value is ignored. A monochromatic color image may be generated by associating the luminance with the sum of the integral values.

  Further, as a second modification example, the positional relationship of the plaque with respect to the contrasted blood vessel is ignored, the total thickness of the plaque or the total sum of the voxel values is obtained, and the total value is associated with the color gradation. An image may be generated.

  As a third modification, the above-described color superimposed image may be displayed by matching the projection direction with the X-ray tube → detector direction of the X-ray imaging apparatus.

  Further, as a fourth modification, the projection direction may be set to be orthogonal to the X-ray tube → detector direction of the X-ray imaging apparatus, and the above-described color superimposed image may be displayed.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described.

  As described above, in the clinical field, there is an increasing movement to introduce CT for examination of the circulatory system such as myocardial infarction and cerebral infarction. In particular, soft plaque, which is considered to be the cause of acute myocardial infarction or cerebral infarction, is often in a place where the stenosis rate that can be discriminated by a circulatory image is not so high, and the effectiveness of CT as a test is increasing.

  And in the X-ray circulatory device, although the site | part of the high stenosis rate by a calcified plaque can be discriminate | determined, it is difficult to pinpoint the position of the soft plaque without a high stenosis. Therefore, when performing a treatment such as stenting of a drug stent for soft plaque, the stent placement is performed at the corresponding site using a circulatory device after confirming the soft plaque site based on the CT image.

  However, in the past, it was impossible to know the plaque position / characteristics etc. on the circulatory organ image, and in particular, soft plaque, which is considered to be the cause of acute cerebral infarction or myocardial infarction, is always in a place with a high stenosis rate This is not the case and cannot be identified by a circulatory device. Therefore, when performing the intervention, it is necessary to confirm the plaque position and properties while comparing with the CT image and proceed with the procedure, leading to an increase in treatment time and inefficiency.

  Therefore, in the fifth embodiment, information useful for intervention, such as a plaque image, is extracted from a CT image collected in advance, and further displayed based on information on the circulatory device. A medical image processing apparatus that can be confirmed as a correct image is provided.

  FIG. 24 is a diagram showing a configuration of a medical image processing apparatus according to the fifth embodiment of the present invention.

  In FIG. 24, this medical image processing apparatus includes an X-ray circulator 30 and the medical image processing apparatus 10 described above.

  The X-ray circulator device 30 has a C-shaped configuration in which the top plate 26, the X-ray generation unit 27, the X-ray detection unit 28, and the X-ray generation unit 27 and the X-ray detection unit 28 are arranged to face each other. The C arm 29 is composed of a plurality of image monitors 17a.

  FIG. 25 is a block diagram showing an example of details of the medical image processing apparatus shown in FIG.

  The top plate 26 is used to place the patient 25, and the X-ray generation unit 27 and the X-ray detection unit 28 are mounted on both ends of the C arm 29 with the top plate 26 interposed therebetween. . When the operation unit 45 is operated, the C arm 29 is driven and rotated by the system control unit 40 and the C arm / top plate mechanism control unit 42. At this time, the X-ray generator 27 and the X-ray detector 28 rotate around the same axis of rotation.

  The X-ray generation unit 27 includes an X-ray tube 33 and an X-ray restrictor 34. The X-ray tube 33 receives power supply from the high voltage generator 37 and emits X-rays toward a flat detector (not shown) in the X-ray detector 28. The high voltage generator 37 constitutes a voltage control unit 35 together with the X-ray control unit 36, and the tube voltage and the filament current are arbitrarily adjusted by the system control unit 40 via the X-ray control unit 36. It is like that. The system control unit 40 controls the overall control operation of the X-ray circulator device 30. The system control unit 40 also controls the flat panel detector 38 and the image processing circuit 41 in the X-ray detection unit 28 in synchronization with the control of X-ray generation by the X-ray tube 33.

  On the other hand, the X-ray detector 28 includes a flat detector 38 and a data converter (not shown). The flat detector 38 detects X-rays incident through the subject 25 from the X-ray tube 33 described above, and outputs an electrical signal corresponding to the intensity to the data converter. The image data converted by the data converter is supplied to the image data storage circuit 43 via the image processing circuit 41. In addition, a plurality of monitors 17 a are connected to the image processing circuit 41 via an image display circuit 44.

  In the image processing circuit 41, image processing is performed so that the image data obtained by the flat detector 38 is displayed on the monitor 17a. The surgeon can perform X-ray diagnostic treatment by operating the operation unit 45 while confirming the image displayed on the monitor 17a.

  On the other hand, the medical image processing apparatus 10a inputs images from the X-ray circulator 30 in addition to the CT image input unit 13, the image extraction unit 14, the projection image creation unit 15, the image superposition unit 16, and the monitor 17b described above. A circulatory image input unit 12 and a registration unit 18 for aligning the circulatory image input by the circulatory image input unit 12 and the image created by the projection image creation unit 15. Configured.

  In the medical image processing apparatus having such a configuration, first, as shown in FIG. 26 (a), 3D data (three-dimensional position information and each position) of the same patient by, for example, a CT examination several days ago is used. Voxel data based on the CT value) is input from the CT image input unit 13. Next, as shown in FIG. 26B, only the voxel data including soft plaque is extracted from the 3D data based on the CT value by the image extraction unit 14. Here, for example, a CT value of 0 to 50 is extracted as a soft plaque.

  Then, as shown in FIG. 26 (c), the current X-ray tube and detector position are acquired from the position input unit 11, the approximate patient position is detected from the position of the top plate, and the projection image creating unit 15 is obtained. A projection image of the soft plaque image is created. Here, a projection image of a soft plaque extracted using a general perspective projection method with the projection center as the X-ray focal point and the projection plane as the detection plane is created.

  Next, an angiographic image is collected by the X-ray circulator device 30 during the intervention in order to perform detailed alignment of the image in the alignment unit 18. (I) The target blood vessel image is extracted by utilizing the fact that the contrast agent portion has a large amount of X-ray absorption and the target blood vessel has continuity. (Ii) On the other hand, only the blood vessel image is extracted from the 3D data from the CT based on the CT value, and a projection image on the detection surface is created in the same manner as the soft plaque projection image described above. In order to extract a blood vessel image clearly, assuming that a contrast medium is used during CT image acquisition, the CT value depends on the X-ray absorption rate of the contrast medium.

  The images in (i) and (ii) should be almost the same except for the moving part such as the heart. Therefore, the best matching was obtained by detecting the image matching amount while moving in parallel. The amount of alignment is calculated from (ii) the amount of parallel translation of the image at the position. A correlation function may be used for image matching.

  Then, as shown in FIG. 26 (d), the projected image 155 of the soft plaque obtained by the projection image creation unit 15 is subjected to a parallel movement process based on the movement amount obtained by the alignment unit 18. The obtained image 156 and the superimposed image 157 are obtained. At this time, the soft plaque may be displayed in a color different from that of the X-ray image so that the soft plaque can be easily identified. Thus, the synthesized image 157 is displayed on the monitor 17b.

  For example, the image displayed on the monitor 17a of the X-ray circulator 30 as shown in FIG. 27A is superimposed on the medical image processing apparatus 10a to be shown in FIG. 27B. Such an image is displayed on the monitor 17b.

  Note that once the parallel movement amount is calculated, accurate X-ray tube, detector, and patient position information on the 3D data can be obtained.

  After alignment, this accurate X-ray tube, detector, and soft plaque projection image based on patient position information is recalculated each time, so that accurate software can be obtained even when the detector or top plate moves or the magnification changes. Plaque superposition can be performed.

  Thus, according to the fifth embodiment, a catheter or the like can be operated while confirming the plaque position, amount, etc. on the circulatory image collected by the circulatory image.

  Next, a modification of the fifth embodiment will be described.

  In the first modification of the fifth embodiment, superposition of soft plaque images is described in the case where the target blood vessel position such as a heart region moves in the alignment unit 18 described above.

  First, as shown in FIG. 28A, the CT image input unit 13 inputs a moving image for one beat of an electrocardiographic waveform in the inputted CT image. Next, in the image extraction unit 14, as shown in FIG. 28B, the electrocardiogram waveform is decomposed into several phases, and a soft plaque image in each phase is extracted.

  Then, as shown in FIG. 28C, the projection image creation unit 15 creates a projection image corresponding to the current position of the X-ray circulator 30 for each phase. Next, in the alignment unit 18, as shown in FIG. 29, the projection image 161 based on the angiographic image in the most stable phase (after contraction or enlargement) and the X-ray circulator 30. The angiographic image 162 is aligned, and alignment with higher accuracy is performed by the same method as in the fifth embodiment described above.

  Further, in the image superimposing unit 16, as shown in FIG. 30, an electrocardiographic waveform is collected together with an X-ray image by the X-ray circulator device 30, and each phase obtained by the image extracting unit 14 is From the soft plaque image, the soft plaque image corresponding to the phase of the electrocardiogram waveform at that time is superimposed.

  In addition, the movement accompanying the movement of the detector and the top plate and the change of the enlargement ratio are performed in the same manner as the fifth embodiment described above.

  Next, a second modification of the fifth embodiment will be described.

  In the above-described fifth embodiment and the first modification of the fifth embodiment, detailed alignment has been performed on the image from the X-ray circulator device 30, but the fifth embodiment In the second modification, an example in which this alignment is not required will be described.

  FIG. 31 is a block configuration diagram illustrating an example of details of a medical image processing apparatus according to a second modification of the fifth embodiment.

  In the figure, a medical image processing apparatus 10b includes a position input unit 11, a CT image input unit 13, an image extraction unit 14, a projection image creation unit 15, an image superposition unit 16, a monitor 17b, It is comprised.

  In such a configuration, when it is not necessary to superimpose on the image of the X-ray circulator 30, the image extraction unit 14 performs image extraction based on the CT value, and a position input unit. The projection image of the CT image itself input from 11 is superposed by the projection image creation unit 15 and the image superposition unit 16.

  The image extracted based on the CT value can be displayed conspicuously, for example, by color display.

  Next, a third modification of the fifth embodiment will be described.

  In the above-described fifth embodiment, when the accuracy is not so required for alignment, the alignment unit 18 is changed from the medical image processing apparatus 10a of FIG. 25 like the medical image processing apparatus 10c shown in FIG. It is good also as a structure remove | excluding.

  Although the embodiments of the present invention have been described above, the present invention can be variously modified without departing from the gist of the present invention other than the above-described embodiments.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

DESCRIPTION OF SYMBOLS 10, 10a, 10b, 10c ... X-ray diagnostic treatment apparatus, 11 ... Position input part, 12 ... Cardiovascular image input part, 13 ... CT image input part, 14 ... Image extraction part, 15 ... Projection image creation part, 16 ... Image superposition unit 17, 17a, 17b ... monitor, 18 ... positioning unit, 19 ... system controller, 25 ... patient, 26 ... top plate, 27 ... X-ray generation unit, 28 ... X-ray detection unit, 29 ... C Arm, 30 X-ray circulator, 33 ... X-ray tube, 34 ... X-ray restrictor, 35 ... Site controller, 36 ... X-ray controller, 37 ... High voltage generator, 38 ... Planar detector, 40 ... System Control unit 41... Image processing circuit 43... Image data storage circuit 44... Image display circuit 45 .. operation unit 100 .. blood vessel 101 .. catheter 102, 102 ₁ , 102 ₂ , 102 ₃ .

Claims (11)

An extraction unit that extracts a contrast blood flow region and a plaque region based on a CT value range from three-dimensional CT data about the subject;
A blood vessel / plaque projection image generation unit that generates a blood vessel / plaque projection image for the contrast blood flow region and the plaque region, and each pixel within a range corresponding to the plaque region on the blood vessel / plaque projection image A color value is assigned, and a gray value is assigned to each pixel in the range corresponding to the contrast blood flow region.
A determination unit for determining the position of the plaque region with respect to the contrast blood flow region on the near side / back side with respect to the projection direction;
A medical image processing apparatus comprising: a display unit that displays the blood flow / plaque projection image superimposed on the projection image.   2. The color value of a specific color among the three primary colors is assigned to each pixel in a range corresponding to the plaque region determined to be located on the near side with respect to the contrast blood flow region. The medical image processing apparatus described.   3. A color value of another color among the three primary colors is assigned to each pixel in a range corresponding to the plaque region determined to be located on the back side with respect to the contrast blood flow region. The medical image processing apparatus described in 1.   2. The medical device according to claim 1, wherein each pixel within a range corresponding to the plaque region on the blood vessel / plaque projection image is assigned a luminance corresponding to a thickness of the plaque region or a voxel integral value. Image processing device.   The color gradation corresponding to the thickness of the plaque region or the voxel integral value is assigned to each pixel within a range corresponding to the plaque region on the blood vessel / plaque projection image. Medical image processing apparatus.   The blood vessel / plaque projection image generation unit has an external X-ray circulation having an X-ray tube that generates X-rays and an X-ray detector that detects the X-rays in order to capture an X-ray image of the subject. The medical image processing apparatus according to claim 1, wherein the projection image and the plaque projection image are created in accordance with a projection direction corresponding to a position of the X-ray tube and the X-ray detector received from the device. An extraction means for extracting a selected region based on a CT value from the three-dimensional data;
The blood vessel / plaque projection image generation unit superimposes the selection region on a projection image based on positional information of the top plate, the X-ray tube, and the X-ray detector by the X-ray circulator device. The medical image processing apparatus according to claim 6. An extraction means for extracting a selected region based on a CT value from the three-dimensional data;
The blood vessel / plaque projection image generation unit converts the projection image based on positional information of the top plate, the X-ray tube, and the X-ray detector by the X-ray circulator, and further converts the X-ray circulator The medical image processing apparatus according to claim 6, wherein the medical image processing apparatus superimposes the image on an X-ray image.   The medical image processing apparatus according to claim 6, wherein alignment of a blood flow contrast image collected by the X-ray circulatory apparatus and a projection image of blood flow from a CT apparatus is performed.   The medical image processing apparatus according to claim 6, wherein an X-ray image by a circulatory device and a selection region based on a CT value are superimposed on the blood vessel / plaque projection image for each phase of an electrocardiographic waveform.   The medical image processing apparatus according to claim 1, wherein the extraction unit extracts plaque information based on a CT value.

Images