JP5022667B2 - Medical image processing apparatus and medical image processing method - Google Patents

Description

  The present invention relates to a technique for displaying a CT (computerized tomography) image, and more particularly to a medical image processing apparatus and a medical image processing method for setting a projection plane of a CT image to be displayed and evaluating a stenosis rate or vascular property of a coronary artery. .

  There has been proposed an IVR (interventional radiology) -CT apparatus in which an X-ray CT apparatus and an X-ray imaging apparatus having a C-arm that is a substantially C-shaped supporter are combined (see, for example, Patent Document 1). ).

  The X-ray CT apparatus includes a CT mount (gantry) having a hollow portion around which an X-ray generation source and an X-ray detector are provided, and is placed on the top plate of the bed in the hollow portion. While introducing the subject (patient), the X-ray transmission information (projection data) in each direction about the subject is collected while rotating the X-ray generation source and the X-ray detector around the cavity, and based on this, the tomogram is collected. It reconstructs the image.

  On the other hand, the X-ray imaging apparatus includes an X-ray generation source provided at one end of the C-arm and an I.D. I. (Image Intensifier) is used for X-ray imaging. In particular, it is an apparatus used for the purpose of angiography in a subject. This is generally called an angio device. The angiography apparatus can simultaneously perform X-ray imaging in parallel with the insertion operation of the catheter into the subject (that is, surgery or examination by a doctor) or the like.

  In such an IVR-CT apparatus, the CT mount in the X-ray CT apparatus and the C arm in the angio apparatus can be operated or positioned side by side in the same space. For example, it is possible to determine how to perform an X-ray examination in the other apparatus based on information about the subject acquired by one apparatus, and to put it into practice without taking a relatively long time. Etc. are characteristic.

At present, blood vessel running (blood vessel core line) is extracted from CT reconstruction data, and a CPR (curved multi-planar reconstruction) image, a short-axis image (horizontal image), and a VR (volume rendering) image along the blood vessel running are extracted. Visual blood vessel evaluation by An image display in which a curved surface constituting a blood vessel core line is projected has been proposed as a display that can be easily diagnosed by the observer's sense. Particularly in the diagnosis of the heart, it is more effective to display the image in the same projection direction (observer's line-of-sight direction) as the imaging direction in coronary angiography.
JP 2002-102220 A

  In order to evaluate blood vessel properties such as stenosis rate evaluation on a CT image, it is effective to display the CT image in the same projection direction (observer's line-of-sight direction) as the imaging direction of the angio image. However, since it is difficult to generate a CT image at the same heartbeat phase timing as the angiographic image because of the difference in modalities, it is difficult to accurately reproduce the same projection direction as the imaging direction of the angio image on the CT image.

  In addition, when performing PCI (percutaneous coronary intervention), which is a method of expanding a coronary artery narrowed due to arteriosclerosis using a catheter, an optimal imaging direction is set while irradiating the subject with X-rays. However, setting (retrieval) of the imaging direction takes time, and X-ray exposure to the subject being set is a problem. I want to reduce the X-ray exposure by setting the diseased part and the optimal imaging direction using the CT images taken in advance, but the purpose is to reproduce the imaging direction in coronary angiography from the display direction of the CT image It is difficult to use a projection image of only blood vessels.

  The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide a medical image processing apparatus and a medical image processing method capable of reproducing on a CT image the same projection direction as the imaging direction in an angio image. And

  A second object of the present invention is to provide a medical image processing apparatus and a medical image processing method capable of accurately and accurately performing vascular property evaluation such as stenosis rate evaluation.

  Furthermore, a third object of the present invention is to provide a medical image processing apparatus and a medical image processing method capable of performing PCI with a shorter operation time and with a smaller exposure dose to a subject.

The medical image processing apparatus according to the present invention includes an angio image acquisition means for acquiring a required angio image from a plurality of angio images in time series, as described in claim 1 to solve the above-described problem, An angio image imaging direction acquisition means for acquiring an imaging direction as supplementary information included in the required angio image data, and a CT image acquisition means for acquiring a three-dimensional CT image having a heartbeat phase closest to the required angio image When a blood vessel portion extracting means for extracting a blood vessel portion that is included in the 3-dimensional CT image, the blood vessel portions, and generates a 3-dimensional projection image obtained by projecting the imaging direction as the projection direction, of the three-dimensional a projection image generating means for generating a 3-dimensional projection image corresponding to the projection direction after changing the projection image, the display control hand for displaying the said Doppler image and the 3-dimensional projection image And, with a.

The medical image processing apparatus according to the present invention provides an angio image acquisition means for acquiring a required angio image from a plurality of angio images in time series as described in claim 10 in order to solve the above-described problem. An angio image imaging direction acquisition means for acquiring an imaging direction as supplementary information included in the data of the required angio image, and a CT image for acquiring a three-dimensional CT image having a heartbeat phase closest to the required angio image An obtaining unit; a blood vessel part extracting unit for extracting a blood vessel part included in the three-dimensional CT image; a projection direction determining unit for determining a projection direction; and a three-dimensional projection obtained by projecting the blood vessel part from the projection direction. A projection image generating means for generating an image; a contrast image extracting means for extracting a contrast image included in the required angio image; and the three-dimensional projection image and the contrast image are displayed. A display control means for controlling the said projection direction determination means, by comparing the contrast image and the blood vessel portions, determining the projection direction corresponding to the imaging direction of the imaging image.

Further, the medical image processing apparatus according to the present invention, as described in claim 17 to solve the problems described above, from the time series a plurality of angiographic images generated by angiography apparatus, the required Doppler image An angio image acquisition means for acquiring, an angio image imaging direction acquisition means for acquiring an imaging direction as supplementary information included in the data of the required angio image, and a three-dimensional CT having a heartbeat phase closest to the required angio image CT image acquisition means for acquiring an image, blood vessel portion extraction means for extracting a blood vessel portion included in the three-dimensional CT image, and a three-dimensional projection image obtained by projecting the blood vessel portion with the imaging direction as the projection direction with resulting, a projection image generation means for generating a 3-dimensional projection image corresponding to the projection direction after changing the projection image of the three-dimensional, and the projected image of the three-dimensional Display control means for displaying the serial Doppler image, and the viewpoint direction correspondence information generation means for generating viewpoint direction correspondence information that associates each other view direction and the imaging direction and the projection direction of the variable Sarago, the a, based on the viewpoint direction correspondence information, controls the position of the C-arm of the variable Sarago the angiography apparatus as an imaging direction of the Doppler image is obtained which corresponds to the direction of projection.

The medical image processing method according to the present invention provides an angio image acquisition in which a required angio image is acquired from a plurality of angio images in time series as described in claim 20 in order to solve the above-described problem. An angio image capturing direction acquisition step in which an imaging direction as supplementary information included in the data of the required angio image is acquired, and a three-dimensional CT image having a heartbeat phase closest to the required angio image is acquired. A CT image acquisition step, a blood vessel portion extraction step in which a blood vessel portion included in the three-dimensional CT image is extracted, and a three-dimensional projection image in which the blood vessel portion is projected as the projection direction is generated. A projection image generation step, a display step in which the three-dimensional projection image and the angio image are displayed, and a mutual viewpoint of the projection direction after changing the projection direction and the imaging direction It has a viewing direction correspondence information generation step of generating a view direction correspondence information that associates direction, a.

  According to the medical image processing apparatus and the medical image processing method according to the present invention, the same projection direction as the imaging direction in the angio image can be reproduced on the CT image.

  Further, according to the medical image processing apparatus and the medical image processing method according to the present invention, blood vessel property evaluation such as stenosis rate evaluation can be performed accurately and accurately.

  Furthermore, according to the medical image processing apparatus and the medical image processing method of the present invention, it is possible to perform PCI with a shorter operation time and a smaller exposure dose to the subject.

  Embodiments of a medical image processing apparatus and a medical image processing method according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing an overall configuration of an IVR (interventional radiology) -CT (computerized tomography) apparatus equipped with a medical image processing apparatus according to the present invention.

  FIG. 1 shows an IVR-CT apparatus 10 in which a CT mount in an X-ray CT apparatus and a C arm in an angio apparatus coexist in the same space. A CT image generating apparatus, an angio image generating apparatus, and a medical image according to the present invention by a computer integrated with the IVR-CT apparatus 10 or a computer connected online to the IVR-CT apparatus 10 via a communication line. A processing device is provided. Alternatively, the medical image processing apparatus according to the present invention is provided by a computer that is off-line from the IVR-CT apparatus 10. Hereinafter, a case where a CT image generation device, an angio image generation device, and a medical image processing device according to the present invention are provided by a computer connected online to the IVR-CT device 10 via a communication line will be described as an example.

  The IVR-CT apparatus 10 generally includes a bed 11 on which a subject (patient) is placed, an X-ray CT apparatus 12 that collects X-ray transmission information (projection data) in each direction regarding the subject, X-ray imaging apparatus (hereinafter referred to as “angio apparatus”) that can simultaneously perform X-ray imaging in parallel with the catheter insertion operation (ie, surgery or examination by a doctor) and the like. 13, a computer (shown in FIG. 2), an input device 14 for sending an input signal to the computer, and a display device 15 for displaying an image.

  The couch 11 is provided with a leg 21 and a top plate 22 installed on the leg 21. The top plate 22 is provided so that the subject can be placed and the subject can be moved in the body axis direction (front-rear direction). The top plate 22 may be provided so that the subject can be moved in the left-right direction or the up-down direction.

  The X-ray CT apparatus 12 includes a CT mount 31 having a cavity H into which the top plate 22 can be inserted. An X-ray generator 33 and an X-ray detector 34 (both shown in FIG. 2) are rotatable along the surrounding area in the CT mount 31 of the X-ray CT apparatus 12 and around the cavity H. Provided. Further, the CT mount 31 operates in a direction (front-rear direction) in which the top plate 22 can be introduced into or led out from the cavity H thereof. Further, the CT mount 31 can be tilted in the front-rear direction in addition to the front-rear direction, and its posture can be changed. This makes it possible to acquire an X-ray image that is sliced in an oblique direction with respect to the subject.

  The angio device 13 is provided with a substantially C-shaped supporter (hereinafter referred to as “C-arm”) 41 that covers the bed 11 from the side. The C-arm 41 of the angio device 13 is provided with an X-ray generator 42 at one end and an X-ray detector 43 at the other end. The X-ray detection apparatus 43 includes, for example, an I.F. which converts transmitted X-rays transmitted through the subject into an optical image. I. (Image intensifier) and this I.I. I. An optical system that corrects the optical image output from the camera to an appropriate size and an X-ray TV camera that converts the optical image into a video signal are installed. Note that the X-ray generator 42 and the X-ray detector 43 are arranged so as to sandwich the bed 11 or the subject in a normal state. The “normal state” here is mainly intended for “at the time of X-ray imaging”.

  The angio apparatus 13 can simultaneously perform X-ray imaging related to angiography or the like while performing an operation or examination by a doctor such as inserting a catheter into the body of the subject. . The C arm 41 is connected to a fixed arm 44 provided so as to cover the arm from the outside via a connection portion 45. The connecting portion 45 is configured to be able to slide the C arm 41 as indicated by an arrow C with respect to the fixed arm 44. The fixed arm 44 is rotatably attached to a fulcrum 47 having one end provided on the ceiling. The fixed arm 44 and the C arm 41 are rotated by the fulcrum 47 as indicated by an arrow D. Furthermore, the fulcrum 47 is installed through the base 48 between the ceiling surfaces. The base 48 moves along a ceiling rail (not shown).

  The bed 11 in the present invention is a fixed type. Moreover, it is preferable that the leg 21 is provided in a place that does not interfere with the operation of the CT mount 31 and the C arm 41. Therefore, in FIG. 1, legs 21 having a substantially rectangular parallelepiped shape are provided along the extreme end of the top plate 22. In addition, although the bed 11 was made into the fixed form, it is not limited to this form in particular.

  The input device 14 is installed in the vicinity of the bed 11. More specifically, the input device 14 is installed on the upper side of the leg 21 and on the side of the bed 11. Examples of the input device 14 include an LCD (Liquid Crystal Display) panel 14a and a numeric keypad 14b. The operation or positioning of the CT mount 31 and the C arm 41 can be controlled by an operation through the input device 14.

  The display device 15 includes a first monitor 15a that mainly displays a CT image generated by a computer and a second monitor 15b that mainly displays an angio image.

  FIG. 2 is a block diagram showing the IVR-CT apparatus 10 and a computer that is a component of the IVR-CT apparatus 10.

  As described with reference to FIG. 1, the IVR-CT apparatus 10 includes a bed 11, an X-ray CT apparatus 12, an angio apparatus 13, an input apparatus 14, a display apparatus 15, and a computer 50, and the bed 11 and the X-ray CT apparatus 12. The angio device 13 and the computer 50 are interconnected via a network N such as a LAN (local area network) as a common signal transmission path.

  The couch 11 includes a top plate drive control device 61 that generates a control signal for the operation of the top plate 22 under the control of the computer 50, and a top plate that drives the top plate 22 by a control signal generated by the top plate drive control device 61. A drive mechanism 62 is provided.

  The X-ray CT apparatus 12 includes an X-ray control apparatus 71 that controls X-rays under the control of the computer 50, and an X-ray generation apparatus via a slip ring (not shown) that generates high voltage generated continuously or periodically. A high voltage generator 72 applied to the computer 33, a CT gantry drive controller 73 that generates a control signal for the operation of the CT gantry 31 under the control of the computer 50, and a CT gantry based on the control signals generated by the CT gantry drive controller 73. And a CT mount drive mechanism 74 for driving the drive 31. Further, the X-ray CT apparatus 12 is provided with a data acquisition circuit 75, a non-contact data transmission apparatus 76, and a preprocessing apparatus 77.

  The data acquisition circuit 75 includes an IV converter (not shown) that converts a current signal of each channel of the X-ray detector 34 into a voltage, and the voltage signal periodically in synchronization with an X-ray exposure cycle. An integrator for integration (not shown), a preamplifier (not shown) for amplifying the output signal of the integrator, and an A / D converter (not shown) for converting the output signal of the preamplifier into a digital signal are provided for each channel. It is equipped with.

  The non-contact data transmission device 76 realizes non-contact data transmission by using a digital signal (pure raw data) as an output of the data collection circuit 75 via light or magnetism.

  The pre-processing device 77 corrects the sensitivity non-uniformity between channels for the pure raw data received via the non-contact data transmission device 76, and it is extremely sensitive to X-ray strong absorbers, mainly metal parts. Projection data is generated by executing pre-processing such as correction of signal intensity drop or signal dropout.

  The angio device 13 includes an X-ray control device 81 that controls X-rays under the control of the computer 50, and a high-voltage generation device 82 that applies a high voltage generated continuously or periodically to the X-ray generation device 42. A C-arm drive control device 83 that generates a control signal for the operation of the C-arm 41 under the control of the computer 50, and a C-arm drive mechanism 84 that drives the C-arm 41 by the control signal generated by the C-arm drive control device 83. Are provided.

  The computer 50 includes basic hardware such as a CPU (central processing unit) 91, a ROM (read only memory) 92, a RAM (random access memory) 93, and an HD (hard disk) 94, and the CPU 91 transmits common signals. The hardware components constituting the computer 50 are interconnected via a bus B as a path. Note that the computer 50 may include a communication control device 95 and a drive 97.

  When a command is input by operating the input device 14 by the user, the CPU 91 executes a program stored in the ROM 92. The CPU 91 also stores a program stored in the HD 94, a program transferred from the network N and received by the communication control device 95 and installed in the HD 94, a flexible disk installed in the drive 97, a CD-ROM (compact disc- A program read from a removable recording medium 97a such as a read only memory (MO), a magneto optical disc (MO), a DVD (digital versatile disc), a magnetic disk, and a semiconductor memory and loaded into the HD 94 is loaded and executed. To do. By executing the program, the computer 50 functions as a CT image generation device, an angio image generation device, and a medical image processing device.

  The ROM 92 reads an OS (operating system) from the HD 94, expands it to the RAM 93, and loads and starts the IPL (initial program loading) and BIOS (basic input / output system) that controls peripheral devices such as the input device 14 and the drive 97. And a non-volatile storage device for storing data.

  The RAM 93 is a volatile storage device used for work memory and temporary storage of the CPU 91. The ROM 92 may be a rewritable type PROM (programmable ROM) even if it is a rewritable mask ROM.

  The HD 94 includes programs installed in the medical image processing apparatus 60 (including an OS and the like in addition to a CT image generation program 94a, an angio image generation program 94b, and a medical image processing program 94c as application programs), and a CPU 91 performs processing. It is a storage device that stores data necessary for the above (including a three-dimensional CT image and an angio image). Further, the use of a graphical user interface (GUI) capable of using a graphic on the screen of the display device 14 and performing basic operations by the input device 14 can be provided by the OS.

  The communication control device 95 includes, for example, an IEEE (institute of electrical and electrical engineers) 1394 port, a USB (universal serial bus) port, a NIC (network interface card) for LAN connection, and an ce The communication control according to each standard is performed. Further, the communication control device 95 can be connected to the network N which is the Internet through a telephone line such as an analog modem, TA (terminal adapter) and DSU (digital service unit), and ADSL (asymmetric digital subscriber line) modem. Thus, the computer 50 can be connected to the network N from the communication control device 95.

  The drive 97 is detachable from the recording medium 97a, reads out data (including a program) recorded on the recording medium 97a, outputs the data on the bus B, and is supplied via the bus B. Data is written to the recording medium 97a. Here, the program executed by the CPU 91 can be stored (recorded) temporarily or permanently in the recording medium 97a. Such a recording medium 97a can be provided as so-called package software.

  In the computer 50 configured as described above, the CPU 91 executes the CT image generation program 94a to control the bed 11 and the X-ray CT apparatus 12 to generate and store a three-dimensional CT image. In the computer 50, the CPU 91 executes the angio image generation program 94b to generate and store an angio image. Further, the CPU 91 executes the medical image processing program 94c to generate and display a projection image whose projection direction is the imaging direction of a required angio image.

  FIG. 3 is a functional block diagram showing a first embodiment of a medical image processing apparatus that functions by executing a medical image processing program 94c.

  In the computer 50, the CPU 91 executes a medical image processing program 94 c installed in the computer, whereby an angio image acquisition unit 101, an angio image imaging direction acquisition unit 102, a CT image acquisition unit 103, a blood vessel part extraction unit 104, a projection image It functions as a generation unit 105, a contrast image extraction unit 106, a display control unit 107, and a blood vessel property evaluation unit 108. Moreover, it may function as viewpoint direction association information generation means (not shown). Therefore, when the CPU 91 executes the medical image processing program 94c installed in the computer 50, the computer 50 functions as a medical image processing apparatus.

  The angio image acquisition means 101 has a function of acquiring a required angio image 94e selected by operating the input device 14 from a plurality of angio images stored in a storage device such as the HD 94 in time series.

  The angio image imaging direction acquisition unit 102 has a function of acquiring an imaging direction (observer's line-of-sight direction) as incidental information included in the data of the angio image 94e.

  The CT image acquisition unit 103 has a function of acquiring a required three-dimensional CT image 94d corresponding to the angio image 94e acquired by the angio image acquisition unit 101 from a three-dimensional CT image stored in a storage device such as an HD 94. Have For example, the CT image acquisition unit 103 acquires a three-dimensional CT image 94d having a heartbeat phase closest to the angio image 94e from the heartbeat phase information.

  The blood vessel portion extraction means 104 performs an operation for determining the position of the blood vessel portion (blood vessel running) included in the three-dimensional CT image 94d using the input device 14, and an input signal input to the computer 50 by the position determination operation. And a function of extracting (acquiring) a blood vessel portion included in the three-dimensional CT image 94d. Alternatively, it has a function of automatically extracting a blood vessel portion included in the three-dimensional CT image 94d from a difference in luminance or the like in the three-dimensional CT image 94d.

  The projection image generation means 105 is a three-dimensional projection in which the blood vessel portion extracted by the blood vessel portion extraction means 104 is projected in the predetermined direction, for example, the imaging direction of the angio image 94e acquired by the angio image imaging direction acquisition means 102. It has a function of generating a projection image (for example, a three-dimensional CT curved surface projection image). Further, the projection image generation means 105 has a function of generating a three-dimensional CT curved surface projection image in the projection direction after being changed by manual input.

  The contrast image extraction means 106 performs the position determination operation of the blood vessel portion (contrast image) included in the angio image 94e by the user using the input device 14, and based on the input signal input to the computer 50 by the position determination operation. And a function of extracting a contrast image included in the angio image 94e. Alternatively, it has a function of automatically extracting a contrast image included in the angio image 94e from a difference in luminance or the like of the angio image 94e. In the case where the angio image is a difference image, the contrast image extracting means 106 may be omitted.

  The display control unit 107 has a function of superimposing and displaying on the display device 15 the three-dimensional CT curved surface projection image generated by the projection image generation unit 105 and the contrast image extracted by the contrast image extraction unit 106.

  Further, based on an input signal input to the computer 50 when the user performs a change operation of the projection direction using the input device 14, the projection image generation unit 105 generates a three-dimensional CT curved surface in the projection direction after the change operation. A function of generating a projected image;

  The vascular property evaluation unit 108 has a function of performing vascular property evaluation such as stenosis rate evaluation based on the three-dimensional CT curved surface projection image generated by the projection image generation unit 105.

  Further, the viewpoint direction association information generation means associates the viewpoint direction association information in which the projection directions of the three-dimensional CT curved surface projection image displayed on the display device 15 and the imaging directions of the angio image 94e are associated with each other. It has the function to generate.

  In the present invention, the single computer 50 functions as a CT image generation device, an angio image generation device, and a medical image processing device. However, the present invention is not limited to this case, and the computer 50 is not limited to the CT image generation device and the angio image processing device. Another computer that functions as an image generation apparatus and is interconnected to the network N, such as a viewer or a workstation, may function as a medical image processing apparatus. Further, the computer 50 may function as a CT image generation device and an angio image generation device, and a computer offline with the network N may function as a medical image processing device.

  Next, the operation of generating a CT image and an angio image by the IVR-CT apparatus 10 will be described with reference to FIGS.

  First, the user operates the input device 14, and an execution command signal for the CT image generation program 94 a is input from the input device 14 to the CPU 91 of the computer 50. When an execution command signal is input to the CPU 91, the CPU 91 controls the top plate drive control device 61 of the bed 11, the X-ray control device 71 of the X-ray CT device 12, and the CT gantry drive control device 73, CT imaging is performed on the subject placed on the top plate 22 of the bed 11. A high voltage generated continuously or periodically by the high voltage generator 72 under the control of the computer 50 is applied to the X-ray generator 33 via a slip ring (not shown). As a result, X-rays are emitted from the X-ray generator 33 toward the subject, and the X-ray detector 34 detects X-rays that have passed through the subject.

  In the IV converter (not shown) of the data acquisition circuit 75, the current signal of each channel of the X-ray detector 34 is converted into a voltage, and in the same integrator (not shown), the voltage signal is exposed to X-rays. It is integrated periodically in synchronization with the period. The preamplifier (not shown) of the data acquisition circuit 75 amplifies the output signal of the integrator, and the A / D converter (not shown) converts the output signal of the preamplifier into a digital signal.

  In the non-contact data transmission device 76, non-contact data transmission is realized by using pure raw data, which is an output of the data collection circuit 75, via light or magnetism. Next, the pre-processing device 77 corrects the non-uniform sensitivity between channels with respect to the pure raw data received via the non-contact data transmission device 76, and also uses an X-ray strong absorber, mainly metal parts. Pre-processing such as correction of an extreme decrease in signal intensity or signal dropout is executed, and projection data is generated. The projection data generated by the preprocessing device 77 is projection data for one circumference of the subject, 360 °, or 180 ° + view angle. This projection data is stored in the HD 94 of the computer 50 as digital data.

  Further, the CPU 91 performs an image reconstruction process on the projection data, thereby generating a three-dimensional CT image including a blood vessel portion. The three-dimensional CT image is displayed on the first monitor 15 a of the display device 15 and is stored in the HD 94 of the computer 50. FIG. 4 is a diagram illustrating an example of a three-dimensional CT image including a blood vessel portion displayed on the first monitor 15a. Note that the three-dimensional CT image may be stored in the recording medium 97a via the memory, the HD 94, or the drive 97.

  On the other hand, the user operates the input device 14, and an execution command signal for the angio image generation program 94 b is input from the input device 14 to the CPU 91 of the computer 50. When an execution command signal is input to the CPU 91, the angio device 13 is controlled to generate an angio image by coronary angiography. The angio image is displayed on the second monitor 15 b of the display device 15 and is stored as digital data in the HD 94 of the computer 50. FIG. 5 is a diagram showing an example of an angio image including a coronary angiogram displayed on the second monitor 15b. The angio image may be stored in the recording medium 97a via the memory, the HD 94, or the drive 97.

  Here, for example, the generation of an angio image has two modes. That is, the X-ray image including the contrast agent (flow) is simply generated by the X-ray imaging as usual by the angio device 13, and the “DA (digital angiography) mode” for displaying and storing the X-ray image, and the contrast agent By acquiring (subtraction processing) a difference image between an X-ray image (mask image) that does not include (image) and an X-ray image (contrast image or live image) that includes (image) In addition, a “DSA (digital subtraction angiography) mode” capable of displaying and storing an X-ray image that captures the flow more clearly can be implemented.

  Next, the medical image processing method according to the present embodiment will be described with reference to the flowchart shown in FIG.

  The user operates the input device 14, and an execution command signal for the medical image processing program 94 c is input from the input device 14 to the CPU 91 of the computer 50.

  When the execution command signal is input to the CPU 91 and the user operates the input device 14 from a plurality of angio images stored in a storage device such as the HD 94 in time series, the selected required angio image 94e is obtained. (Step S1). Next, the imaging direction (observer's line-of-sight direction) as supplementary information included in the data of the angio image 94e acquired in step S1 is acquired (step S2).

  Also, a three-dimensional CT image 94d corresponding to the angio image 94e acquired in step S1 is acquired from the three-dimensional CT image stored in a storage device such as the HD 94 (step S3). In step S3, for example, a CT image 94d having the heartbeat phase closest to the angio image 94e is acquired from the heartbeat phase information.

  Next, the user uses the input device 14 to determine the position of the blood vessel portion included in the three-dimensional CT image 94d. Based on an input signal input to the computer 50 by the position determination operation, a blood vessel portion is extracted from a three-dimensional CT image 94d representing information in a three-dimensional region regarding the desired subject. Alternatively, a blood vessel portion included in the three-dimensional CT image 94d is extracted from the difference in CT value, luminance, etc. of the three-dimensional CT image 94d (step S4).

  The region of the blood vessel part is (1) the part of the blood vessel designated by the user is designated on the three-dimensional CT image 94d, and (2) the CT value, luminance, etc. of the three-dimensional image data are provided with a contrast agent by threshold processing. Region (region with blood) is extracted, and (3) in the extracted contrast agent region (blood region), a region continuous to a point specified by the user is extracted, thereby obtaining a blood vessel running state Can be obtained.

  Alternatively, as another region extraction method for blood vessel parts, (1) the user designates a part of the designated blood vessel on the three-dimensional CT image 94d, and (2) the CT value, luminance, etc. of the three-dimensional image data are threshold values. Extracting a region with contrast agent (region with blood) by processing, etc. (3) In the extracted region of contrast agent (blood region), obtaining a core line that is continuous to the point designated by the user A blood vessel core line may be obtained, and blood vessel information representing the blood vessel running state may be obtained from the core line (for example, disclosed in Japanese Patent Application No. 2005-63902). The core line range may be manually designated by the user.

  Next, a three-dimensional CT curved surface projection image is generated by projecting the blood vessel portion extracted in step S4 with the imaging direction of the angio image acquired in step S2 as the projection direction (step S5).

  In addition, the user performs an operation for determining the position of the contrast image included in the angio image 94 e using the input device 14. Based on the input signal input to the computer 50 by the position determination operation, a contrast image included in the angio image 94e regarding the desired subject is extracted. Alternatively, a contrast image included in the angio image 94e is automatically extracted from the difference in brightness or the like of the angio image 94e (step S6). If the angio image 94e is a difference image, step S6 may be omitted.

  Next, the three-dimensional CT curved surface projection image generated in step S5 and the contrast image extracted in step S6 are superimposed and displayed on the display device 15 (step S7). FIG. 7 is a diagram illustrating an example of superimposed display of a three-dimensional CT curved surface projection image and a contrast image. The CT curved surface projection image at this time is a coronary artery portion within a predetermined range, and is displayed in a state in which an image of a ventricle portion or the like is removed, thereby improving visibility when aligning positions.

  Here, it is determined whether or not the user has used the input device 14 to change the projection direction of the three-dimensional CT curved surface projection image (step S8). When the determination in step S8 is Yes, that is, when it is determined that the input device 14 is used by the user and the projection direction of the three-dimensional CT curved surface projection image is changed, the input signal input to the computer 50 is used. A three-dimensional CT curved surface projection image in the projection direction after the changing operation is generated (step S5). The user uses the input device 14 to rotate the three-dimensional CT curved surface projection image (volume) on the display screen so that the three-dimensional CT curved surface projection image in the projection direction after the change operation overlaps the contrast image.

  FIG. 8 is a diagram illustrating an example of a superimposed display of a three-dimensional CT curved surface projection image and a contrast image in the projection direction after the change operation. On the other hand, if the determination in step S8 is No, that is, if it is determined that the user has not changed the projection direction using the input device 14, the projection direction of the superimposed three-dimensional CT curved surface projection image is displayed. The viewpoint direction association information that associates the viewpoint directions with the imaging direction of the angio image is generated, and vascular property evaluation such as stenosis rate evaluation is performed on the CT curved surface projection image superimposed and displayed in step S7. (Step S9). The generated viewpoint direction association information is stored in a storage device such as HD94.

  Note that step S8 is not always necessary, and blood vessel property evaluation may always be performed on the CT curved surface projection image in the projection direction acquired in step S2. In step S8, the user may instruct that there is no operation for changing the projection direction by clicking a position confirmation button (not shown) on the screen.

  Subsequently, when PCI (Percutaneous Coronary Intervention), which is a method of expanding the coronary artery narrowed by arteriosclerosis using a catheter, is performed by the angio device 13, a three-dimensional CT curved surface is provided on the first monitor 15a of the display device 15. A projected image is displayed. After the user arbitrarily changes the projection angle of the CT curved surface projection image using the input device 14, when the confirmation button (not shown) on the screen is clicked, the projection direction of the three-dimensional CT curved surface projection image is confirmed. Is done. Here, when the projection direction of the three-dimensional CT curved-surface projection image is changed, the angle information of the C arm 14 (corresponding to the imaging direction) LAO (left anterior oblige view) / RAO ( It is also possible to obtain a right animation oblige view (CRA) or a CRA (cranial view) / CAU (caudal view) and display it on the screen.

  When determining the projection direction of the three-dimensional CT curved surface projection image, the projection direction of the three-dimensional CT curved surface projection image displayed on the first monitor 15a and the viewpoint direction association information correspond to the projection direction (substantially the same). The position of the C arm 41 may be controlled so that an angio image in the imaging direction is obtained.

  According to the medical image processing apparatus and the medical image processing method according to the present embodiment, the projection direction of the CT curved surface projection image is preset based on the imaging direction of the angio image 94e, and the CT curved surface projection image and the contrast image are manually set. Thus, the same projection direction as the imaging direction in the angio image 94e can be reproduced on the three-dimensional CT image 94d. Further, by obtaining information that associates the direction of the angio image 94e with the direction of the three-dimensional CT image 94d, information on the imaging direction of the angio device 13 can be obtained from the projection direction of the three-dimensional CT image 94d.

  Further, according to the medical image processing apparatus and the medical image processing method according to the present embodiment, by displaying the CT curved surface projection image in the same projection direction as the imaging direction in the angio image 94e, blood vessel property evaluation such as stenosis rate evaluation can be performed. It can be performed accurately and accurately.

  Furthermore, according to the medical image processing apparatus and the medical image processing method according to the present embodiment, an angio image 94e in the viewpoint direction corresponding to the projection direction of the displayed three-dimensional CT curved surface projection image can be obtained, thereby reducing PCI can be performed in an operation time and with a smaller exposure dose to the subject.

  FIG. 9 is a functional block diagram showing a second embodiment of the medical image processing apparatus that functions by executing the medical image processing program 94c.

  In the computer 50, the CPU 91 executes a medical image processing program 94 c installed in the computer, whereby an angio image acquisition unit 101, an angio image imaging direction acquisition unit 102, a CT image acquisition unit 103, a blood vessel part extraction unit 104, a projection image It functions as a generation unit 105, a contrast image extraction unit 106, a projection direction determination unit 109, a display control unit 107, and a blood vessel property evaluation unit 108.

  The projection direction determination unit 109 compares the blood vessel portion included in the three-dimensional CT curved surface projection image with the contrast image included in the angio image 94e, and corresponds to (similar to) the three-dimensional CT corresponding to the imaging direction of the contrast image. It has a function for obtaining the projection direction of a curved projection image. Specifically, the projection direction determining unit 109 includes a centroid calculating unit 109a and an automatic alignment unit 109b.

  The center-of-gravity calculation unit 109 a has a function of calculating the center of gravity of the blood vessel portion included in the three-dimensional CT curved surface projection image generated by the projection image generation unit 105 and the center of gravity of the contrast image extracted by the contrast image extraction unit 106. Have. For example, the center-of-gravity calculation unit 109a designates, for example, three points on the blood vessel portion and the contrast image included in the three-dimensional CT curved surface projection image. The center-of-gravity calculating unit 109a calculates the center of gravity of the blood vessel portion included in the three-dimensional CT curved surface projection image using three points on the blood vessel portion included in the three-dimensional CT curved surface projection image. The center-of-gravity calculating means 109a calculates the center of gravity of the contrast image using three points on the contrast image.

  The automatic alignment means 109b is such that the vector at each position of the core line of the blood vessel portion included in the three-dimensional CT curved surface projection image is closest to the vector at each position of the core line of the contrast image extracted by the contrast image extraction means 106. It has a function of semi-automatically aligning (changing the projection direction) by rotating the three-dimensional CT curved surface projection image so as to overlap. In addition, the automatic alignment unit 109b generates a 3D CT curved surface projection image so that the centroid of the blood vessel portion and the centroid of the contrast image included in the 3D CT curved surface projection image calculated by the centroid calculating unit 109a are aligned. It has a function of rotating and semi-automatically aligning (changing the projection direction).

  In FIG. 9, the same components as those shown in FIG.

  Next, the medical image processing method according to this embodiment will be described using the flowchart shown in FIG. In the flowchart shown in FIG. 10, the same steps as those in the flowchart shown in FIG.

  When the contrast image is extracted in step S6, the center of gravity of the blood vessel portion included in the three-dimensional CT curved surface projection image generated in step S5 and the center of gravity of the contrast image extracted in step S6 are calculated (step S6). S10).

  Semi-automatic alignment is performed so that the vector at each position of the core line of the blood vessel portion included in the three-dimensional CT curved surface projection image generated in step S5 overlaps the vector of the contrast image extracted in step S6 (step S6). S11). Further, in step S11, the three-dimensional CT curved projection image is rotated and semi-automatically aligned so that the centroid in the three-dimensional CT curved projection image calculated in step S10 matches the centroid in the contrast image. .

  Next, the three-dimensional CT curved surface projection image aligned in step S11 and the contrast image extracted in step S6 are superimposed on the display device 15 (step S7).

  It should be noted that the first embodiment of the medical image processing apparatus is provided with a centroid calculating means 109a and an automatic alignment means 109b, and steps S10 and S11 are inserted after step S6 in the flowchart shown in FIG. The CT curved surface projection image and the contrast image may be superposed manually and semi-automatically.

  In the present invention, the IVR-CT apparatus 10 is used to store a three-dimensional CT image and an angio image in the HD 94 of the computer 50. However, the present invention is not limited to this case. The three-dimensional CT image 94d and the angio image 94e collected by the X-ray CT apparatus 12 and the angio apparatus 13 arranged at remote locations are respectively sent to the computer 50 via the communication line, and three-dimensionally transmitted to the HD 94 of the computer 50. The CT image 94d and the angio image 94e may be stored.

  In the present invention, the case of obtaining a CT curved surface projection image has been described as an example. However, the present invention is not limited to this case, and a configuration in which a three-dimensional projection image of a CT image is obtained by another projection method may be used.

  According to the medical image processing apparatus and the medical image processing method according to the present embodiment, the projection direction of the CT curved surface projection image is preset based on the imaging direction of the angio image 94e, and the CT curved surface projection image and the contrast image are semi-automatically displayed. Thus, the same projection direction as the imaging direction in the angio image 94e can be reproduced on the three-dimensional CT image 94d. Further, by obtaining information that associates the direction of the angio image 94e with the direction of the three-dimensional CT image 94d, information on the imaging direction of the angio device 13 can be obtained from the projection direction of the three-dimensional CT image 94d.

  Further, according to the medical image processing apparatus and the medical image processing method according to the present embodiment, by displaying the CT curved surface projection image in the same projection direction as the imaging direction in the angio image 94e, blood vessel property evaluation such as stenosis rate evaluation can be performed. It can be performed accurately and accurately.

  Furthermore, according to the medical image processing apparatus and the medical image processing method according to the present embodiment, an angio image 94e in the viewpoint direction corresponding to the projection direction of the displayed three-dimensional CT curved surface projection image can be obtained, thereby reducing PCI can be performed in an operation time and with a smaller exposure dose to the subject.

These are the schematic diagrams which show the whole structure of the IVR-CT apparatus which mounts the medical image processing apparatus which concerns on this invention. The block diagram which shows the computer which is a component of an IVR-CT apparatus and its IVR-CT apparatus. The functional block diagram which shows 1st Embodiment of the medical image processing apparatus which functions by running a medical image processing program. The figure which shows an example of CT image containing the blood-vessel part displayed on a display apparatus. The figure which shows an example of the angio image containing the coronary arteriogram displayed on a display apparatus. The figure which shows the medical image processing method which concerns on 1st Embodiment as a flowchart. The figure which shows an example of the superimposition display of a three-dimensional CT curved-surface projection image and a contrast image. The figure which shows an example of the superimposition display of the three-dimensional CT curved-surface projection image and contrast image in the projection direction after change operation. The functional block diagram which shows 2nd Embodiment of the medical image processing apparatus which functions by running a medical image processing program. The figure which shows the medical image processing method which concerns on 2nd Embodiment as a flowchart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 IVR-CT apparatus 11 Bed 12 X-ray CT apparatus 13 Angio apparatus 14 Input apparatus 15 Display apparatus 50 Computer 94a CT image generation program 94b Angio image generation program 94c Medical image processing program 101 Angio image acquisition means 102 Angio image imaging direction acquisition means 103 CT image acquisition means 104 Blood vessel part extraction means 105 Projection image generation means 106 Contrast image extraction means 107 Display control means 108 Blood vessel property evaluation means 109 Projection direction determination means 109a Center of gravity calculation means 109b Automatic alignment means

Claims (20)

An angio image acquisition means for acquiring a required angio image from a plurality of angio images in time series,
An angio image imaging direction acquisition means for acquiring an imaging direction as incidental information included in the data of the required angio image;
CT image acquisition means for acquiring a three-dimensional CT image having a heartbeat phase closest to the required angio image;
A blood vessel portion extracting means for extracting a blood vessel portion included in the three-dimensional CT image;
Projection image generation for generating a three-dimensional projection image in which the blood vessel portion is projected with the imaging direction as the projection direction, and generating a three-dimensional projection image corresponding to the projection direction after the change of the three-dimensional projection image Means,
A medical image processing apparatus comprising: display control means for displaying the three-dimensional projection image and the angio image. The medical image processing apparatus according to claim 1, wherein the three-dimensional projection image is a three-dimensional CT curved surface projection image. It has a view direction correspondence information generation means for generating viewpoint direction correspondence information that associates each other view direction and the projection direction and the imaging direction of the variable Sarago, the viewpoint and the projection direction of the variable Sarago by the direction correspondence information, the medical image according to claim 1, characterized in that for controlling the position of the C-arm of the variable Sarago angiographic apparatus as an imaging direction of the Doppler image is obtained which corresponds to the direction of projection Processing equipment. Has a contrast image extracting means for extracting a contrast image contained in the desired Doppler image, the display control means, thereby superimpose and the contrast image and 3-dimensional projection image in a projection direction of the variable Sarago The medical image processing apparatus according to claim 1. The medical image processing apparatus according to claim 1, characterized in that it comprises a vascular properties evaluation means for vascular characteristics evaluation based on the 3-dimensional projection image in a projection direction of the variable Sarago. An angio image acquisition means for acquiring a required angio image from a plurality of angio images in time series,
An angio image imaging direction acquisition means for acquiring an imaging direction as incidental information included in the data of the required angio image;
CT image acquisition means for acquiring a three-dimensional CT image corresponding to the required angio image;
A blood vessel portion extracting means for extracting a blood vessel portion included in the three-dimensional CT image;
A projection direction determining means for determining a projection direction;
Projection image generating means for generating a three-dimensional projection image obtained by projecting the blood vessel portion from the projection direction;
A contrast image extracting means for extracting a contrast image included in the required angio image;
Display control means for displaying the three-dimensional projection image and the contrast image;
The projection direction determining means calculates the center of gravity of the blood vessel part and the center of gravity of the contrast image, and rotates the three-dimensional projection image so as to match the center of gravity of the blood vessel part and the center of gravity of the contrast image. Match
The medical image processing apparatus, wherein the projection image generation unit generates a three-dimensional projection image in the projection direction after the alignment . Viewpoint direction association information generating means for generating viewpoint direction association information that associates the viewpoint directions of the projection direction after the alignment and the imaging direction, and the projection direction after the alignment and the viewpoint The medical image according to claim 6 , wherein the position of the C-arm of the angio device is controlled so that an angio image in an imaging direction corresponding to the projection direction after the alignment is obtained based on the direction association information. Processing equipment. An angio image acquisition means for acquiring a required angio image from a plurality of angio images in time series,
An angio image imaging direction acquisition means for acquiring an imaging direction as incidental information included in the data of the required angio image;
CT image acquisition means for acquiring a three-dimensional CT image corresponding to the required angio image;
A blood vessel portion extracting means for extracting a blood vessel portion included in the three-dimensional CT image;
A projection direction determining means for determining a projection direction;
Projection image generating means for generating a three-dimensional projection image obtained by projecting the blood vessel portion from the projection direction;
A contrast image extracting means for extracting a contrast image included in the required angio image;
Display control means for displaying the three-dimensional projection image and the contrast image;
The projection direction determining means rotates and aligns the three-dimensional projection image so that the vector of the blood vessel portion overlaps the vector of the contrast image,
The medical image processing apparatus, wherein the projection image generation unit generates a three-dimensional projection image in the projection direction after the alignment . Viewpoint direction association information generating means for generating viewpoint direction association information that associates the viewpoint directions of the projection direction after the alignment and the imaging direction, and the projection direction after the alignment and the viewpoint 9. The medical image according to claim 8 , wherein the position of the C-arm of the angio device is controlled so that an angio image in an imaging direction corresponding to the projection direction after the alignment is obtained based on the direction association information. Processing equipment. An angio image acquisition means for acquiring a required angio image from a plurality of angio images in time series,
An angio image imaging direction acquisition means for acquiring an imaging direction as incidental information included in the data of the required angio image;
CT image acquisition means for acquiring a three-dimensional CT image having a heartbeat phase closest to the required angio image;
A blood vessel portion extracting means for extracting a blood vessel portion included in the three-dimensional CT image;
A projection direction determining means for determining a projection direction;
Projection image generating means for generating a three-dimensional projection image obtained by projecting the blood vessel portion from the projection direction;
A contrast image extracting means for extracting a contrast image included in the required angio image;
Display control means for displaying the three-dimensional projection image and the contrast image;
The medical image processing apparatus characterized in that the projection direction determining means determines the projection direction corresponding to the imaging direction of the contrast image by comparing the blood vessel portion and the contrast image. The medical image processing apparatus according to claim 6, wherein the three-dimensional projection image is a three-dimensional CT curved surface projection image. The projection image generation unit generates a three-dimensional projection image in the projection direction after the alignment , and the display control unit superimposes the three-dimensional projection image in the projection direction after the alignment and the contrast image. The medical image processing apparatus according to claim 6 , wherein the medical image processing apparatus is displayed. The projection image generation means, before Symbol generates a three-dimensional projection image in a projection direction of the projection direction after the change at the next, the display control means, the three-dimensional projection image in a projection direction of the variable Sarago Concrete The medical image processing apparatus according to claim 10 , wherein the image is superimposed and displayed. The medical image processing apparatus according to claim 6 , further comprising a blood vessel property evaluation unit that performs blood vessel property evaluation based on the three-dimensional projection image. An angio image acquisition means for acquiring a required angio image from a plurality of angio images generated in time series by the angio device;
An angio image imaging direction acquisition means for acquiring an imaging direction as incidental information included in the data of the required angio image;
CT image acquisition means for acquiring a three-dimensional CT image corresponding to the required angio image;
A blood vessel portion extracting means for extracting a blood vessel portion included in the three-dimensional CT image;
A three-dimensional projection image is generated by projecting the blood vessel portion with the imaging direction as the projection direction, and a contrast image included in the required angio image is extracted, and a center of gravity of the blood vessel portion and a center of gravity of the contrast image are extracted. , And by aligning the three-dimensional projection image by rotating the three-dimensional projection image so as to match the centroid of the blood vessel portion and the centroid of the contrast image, the projection direction after the alignment of the three-dimensional projection image Projection image generating means for generating a three-dimensional projection image corresponding to
Display control means for displaying the three-dimensional projection image and the angio image;
Anda view direction correspondence information generation means for generating viewpoint direction correspondence information that associates each other view direction and the projection direction and the imaging direction after the alignment,
A medical image processing apparatus that controls the position of a C-arm of the angio device so that an angio image in an imaging direction corresponding to the projection direction after the alignment is obtained based on the viewpoint direction association information . An angio image acquisition means for acquiring a required angio image from a plurality of angio images generated in time series by the angio device;
An angio image imaging direction acquisition means for acquiring an imaging direction as incidental information included in the data of the required angio image;
CT image acquisition means for acquiring a three-dimensional CT image corresponding to the required angio image;
A blood vessel portion extracting means for extracting a blood vessel portion included in the three-dimensional CT image;
A three-dimensional projection image is generated by projecting the blood vessel portion with the imaging direction as the projection direction, and a contrast image included in the required angio image is extracted, and the vector of the blood vessel portion is converted into a vector of the contrast image. A projection image generating means for generating a three-dimensional projection image corresponding to the projection direction after the alignment of the three-dimensional projection image by rotating and aligning the three-dimensional projection image so as to overlap ;
Display control means for displaying the three-dimensional projection image and the angio image;
Anda view direction correspondence information generation means for generating viewpoint direction correspondence information that associates each other view direction and the projection direction and the imaging direction after the alignment,
A medical image processing apparatus that controls the position of a C-arm of the angio device so that an angio image in an imaging direction corresponding to the projection direction after the alignment is obtained based on the viewpoint direction association information . An angio image acquisition means for acquiring a required angio image from a plurality of angio images generated in time series by the angio device;
An angio image imaging direction acquisition means for acquiring an imaging direction as incidental information included in the data of the required angio image;
CT image acquisition means for acquiring a three-dimensional CT image having a heartbeat phase closest to the required angio image;
A blood vessel portion extracting means for extracting a blood vessel portion included in the three-dimensional CT image;
Projection image generation for generating a three-dimensional projection image in which the blood vessel portion is projected with the imaging direction as the projection direction, and generating a three-dimensional projection image corresponding to the projection direction after the change of the three-dimensional projection image Means,
Display control means for displaying the three-dimensional projection image and the angio image;
Anda view direction correspondence information generation means for generating viewpoint direction correspondence information that associates each other view direction and the projection direction and the imaging direction of the variable Sarago,
Based on the view direction correspondence information, the medical image processing apparatus characterized by controlling the position of the C-arm of the angiography apparatus as an imaging direction of the Doppler image is obtained which corresponds to the projection direction after the change at the next . The medical image processing apparatus according to any one of claims 15 to 17, wherein the three-dimensional projection image is a three-dimensional CT curved surface projection image. The medical image processing apparatus according to any one of claims 15 to 17, characterized in that it has a vascular nature evaluation means for vascular characteristics evaluation based on the projected image of the three-dimensional of the variable Sarago. An angio image acquisition process in which a required angio image is acquired from a plurality of angio images in time series,
An angio image capturing direction acquisition step in which an image capturing direction as supplementary information included in the required angio image data is acquired;
A CT image acquisition step of acquiring a three-dimensional CT image having a heartbeat phase closest to the required angio image;
A blood vessel portion extraction step in which a blood vessel portion included in the three-dimensional CT image is extracted;
A projection image generation step in which a three-dimensional projection image is generated by projecting the blood vessel portion with the imaging direction as the projection direction;
A display step in which the three-dimensional projection image and the angio image are displayed;
A viewpoint direction association information generation step of generating viewpoint direction association information in which the projection directions after the change of the projection direction and the viewpoint directions of the imaging direction are associated with each other. Method.

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