Image processing apparatus, X-ray diagnostic apparatus, and image processing method

Abstract

To provide an image processing device capable of grasping a measurement position of a physiological index on a blood vessel image, a medical image diagnostic device and a blood pressure monitor.SOLUTION: The image processing device according to an embodiment includes an identification part and a display control part. The identification part identifies an acquisition position of an index about a blood flow on an image including blood vessels collected by the medical image diagnostic device. The display control part displays the acquisition position on the image including the blood vessels, and displays the index on a display part in association with the acquisition position.SELECTED DRAWING: Figure 1

Description

Technical Field

[0004] , , , , , , , , , ,

[0001] Embodiments of the present invention relate to an image processing apparatus, an X-ray diagnostic apparatus, and an image processing method.

Background Art

[0002] In recent years, the diagnosis of coronary artery stenosis lesions has been made from two aspects: "anatomical evaluation" that morphologically evaluates the presence or absence of stenosis and the degree of stenosis, and "physiological evaluation" that objectively evaluates the presence or absence of myocardial ischemia and the degree of myocardial ischemia. Further, as physiological indices used in "physiological evaluation", FFR (Fractional Flow Reserve), CFR (Coronary Flow Reserve), etc. have attracted attention. For example, FFR is an index indicating the degree of myocardial ischemia caused by stenosis of the coronary artery, and is represented by the ratio of the maximum coronary blood flow under stenosis to the maximum coronary blood flow without stenosis. Also, for example, CFR is an index indicating the ability to increase coronary blood flow in response to an increase in oxygen demand in the myocardium, and is represented by the ratio of coronary blood flow at rest to coronary blood flow at maximum reactive hyperemia.

[0003] Conventionally, these physiological indices have been calculated by a predetermined measuring device. For example, the measuring device has a pressure sensor-equipped guide wire (pressure wire) and calculates FFR by measuring the internal pressure of the coronary artery. Also, for example, the measuring device has a guide wire (Doppler wire) with an ultrasonic probe attached to its tip, and calculates CFR by measuring the blood flow velocity of the coronary artery with this ultrasonic probe.

Prior Art Documents

Patent Documents

[0004] [[ID=!]]

Patent Document 1

Patent Document 2

Patent Document 3

[0005] The problem that this invention aims to solve is to provide an image processing device that can determine the measurement location of physiological indicators on a vascular image. [Means for solving the problem]

[0006] The image processing apparatus according to this embodiment comprises a specification unit and a display control unit. The specification unit identifies the acquisition location of an index related to blood flow on an image including blood vessels collected by a medical image diagnostic device. The display control unit displays the acquisition location on the image including blood vessels and causes the index to be displayed on the display unit in correspondence with the acquisition location. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a diagram illustrating the outline of the first embodiment. [Figure 2] Figure 2 is a block diagram showing the overall configuration of the X-ray diagnostic apparatus according to the first embodiment. [Figure 3] Figure 3 shows the configuration of the X-ray diagnostic apparatus, measuring apparatus, and ECG (Electrocardiogram) measuring apparatus according to the first embodiment. [Figure 4] Figure 4 is a diagram illustrating the generation of a display image in the first embodiment. [Figure 5] Figure 5 shows an example of the display in the first embodiment. [Figure 6] Figure 6 shows another example of the display in the first embodiment. [Figure 7] Figure 7 shows another example of the display in the first embodiment. [Figure 8] Figure 8 is a diagram illustrating the generation of a display image in the second embodiment. [Figure 9]FIG. 9 is a diagram for explaining the generation of a display image in the third embodiment. [Figure 10] FIG. 10 is a diagram showing a display example in the third embodiment. [Figure 11] FIG. 11 is a diagram showing another display example in the third embodiment. [Figure 12] FIG. 12 is a diagram showing the configuration of an X-ray diagnostic apparatus according to the present embodiment. [Figure 13] FIG. 13 is a diagram showing the appearance of the gantry unit in FIG. 12. [Figure 14] FIG. 14 is a diagram schematically showing a series of operations from DA image collection to completion of guide wire extraction in the present embodiment. [Figure 15] FIG. 15 is a flowchart showing the processing procedure from catheter insertion to reference image selection in FIG. 14. [Figure 16] FIG. 16 is a diagram showing an example of a reference image selected in step S14 in FIG. 15. [Figure 17] FIG. 17 is a flowchart showing the processing procedure during guide wire extraction in FIG. 14. [Figure 18] FIG. 18 is an explanatory diagram of step S35 in FIG. 17. [Figure 19] FIG. 19 is an explanatory diagram of step S36 in FIG. 17. [Figure 20] FIG. 20 is an explanatory diagram of step S37 in FIG. 17. [Figure 21] FIG. 21 is an explanatory diagram regarding the loop operation of steps S31 - S38 in FIG. 17. [Figure 22] FIG. 22 is a diagram showing an example of a display screen of a display in step S38 in FIG. 17. [Figure 23] FIG. 23 is a diagram showing an example of a display screen in which numerical values of FFR values are superimposed on a reference image instead of a mark column on the display screen in FIG. 22. [Figure 24] FIG. 24 is a diagram showing an example of a display screen in which a mark column is superimposed on a fluoroscopic image, switched from the display screen in FIG. 22. [Figure 25] FIG. 25 is a diagram showing an example of a display screen in which numerical values of FFR values are superimposed on a fluoroscopic image instead of a mark column on the display screen in FIG. 22. [Figure 26] FIG. 26 is a side view of a guide wire. [Figure 27] FIG. 27 is a block diagram showing the configuration of an X-ray diagnostic apparatus according to a fourth embodiment. [Figure 28] FIG. 28 is a diagram showing an example of display in the fourth embodiment. [Figure 29] FIG. 29 is a diagram showing the configurations of an X-ray diagnostic apparatus, a measuring apparatus, and an ECG measuring apparatus according to a fifth embodiment. [Figure 30] FIG. 30 is a diagram for explaining myocardial ischemia improvement prediction in the fifth embodiment. [Figure 31] FIG. 31 is a diagram showing an example of display in the fifth embodiment. [Figure 32] FIG. 32 is a diagram showing the generation and an example of display of a display image in other embodiments.

MODE FOR CARRYING OUT THE INVENTION

[0008] Hereinafter, an image processing apparatus, a medical image diagnostic apparatus, and a blood pressure monitor according to embodiments will be described with reference to the drawings. In the first to fifth embodiments, an embodiment of the X-ray diagnostic apparatus 100 will be described.

[0009] (First Embodiment) Figure 1 is a diagram illustrating the overview of the first embodiment. As shown in Figure 1, in the first embodiment, while an X-ray diagnostic device 100 collects images including the blood vessels of the subject P, the measuring device 200 measures FFR, CFR, iFR (instant wave-free ratio), IMR (Index of Microcirculatory Resistance), etc. For example, the operator inserts the pressure sensor-equipped guidewire of the measuring device 200 into the coronary artery of the subject P while viewing the images including the blood vessels collected by the X-ray diagnostic device 100, and measures the intravascular pressure. The operator also measures the intravascular pressure at multiple locations within the coronary artery while appropriately moving the pressure sensor-equipped guidewire. Images including blood vessels (hereinafter referred to as vascular images) are images taken targeting blood vessels such as coronary arteries, and include X-ray images collected under contrast and X-ray images collected without contrast. Furthermore, for example, if the image is collected under contrast by the X-ray diagnostic device 100, it means a contrast-enhanced X-ray image, and if the image is collected under non-contrast conditions by the X-ray diagnostic device 100, it means a non-contrast X-ray image.

[0010] As shown in Figure 1, the X-ray diagnostic device 100 stores a series of vascular images collected during intravascular pressure measurement in its memory unit. Meanwhile, the measurement device 200 calculates FFR, CFR, etc., based on the intravascular pressure measurement data. The X-ray diagnostic device 100 then associates the series of vascular images collected during intravascular pressure measurement with the measurement data measured by the measurement device 200.

[0011] Specifically, the time-series vascular image set collected by the X-ray diagnostic device 100 includes time information for when each vascular image was taken. On the other hand, the intravascular pressure measurement data also includes time information for when each measurement was taken. Therefore, the X-ray diagnostic device 100 uses this time information to associate the vascular image set with the measurement data and extracts the vascular image corresponding to the time phase in which the measurement data was taken from the vascular image set. Then, the X-ray diagnostic device 100 identifies the tip of the guidewire by analyzing the extracted vascular image, thereby identifying the measurement position of each measurement, and displays the index calculated from the measurement data in correspondence with the measurement position identified on the vascular image.

[0012] Figure 2 is a block diagram showing the overall configuration of the X-ray diagnostic apparatus 100 according to the first embodiment. The X-ray diagnostic apparatus 100 according to the first embodiment is a medical image diagnostic apparatus that supports endovascular treatment using catheters, etc., while performing angiography, and the function responsible for image processing can be realized using existing known technology. As shown in Figure 2, the X-ray diagnostic apparatus 100 comprises a stand unit 10 and a computer system 20. Also as shown in Figure 2, the stand unit 10 comprises a patient table 11, a stand 12, a C-arm 13, an X-ray source 14, an X-ray detector 15, and a display unit 16.

[0013] The examination table 11 is movable vertically and horizontally, and the subject P is placed on it. The support frame 12 supports the C-arm 13. The C-arm 13 is rotatable in the direction of arrow R about the Z-axis and holds the X-ray source 14 and the X-ray detector 15 facing each other. The X-ray source 14 has an X-ray tube that emits X-rays and a collimator. The X-ray detector 15 detects the X-rays emitted from the X-ray source 14 and transmitted through the subject P. The display unit 16 displays X-ray images and the like generated by the computer system 20.

[0014] The computer system 20 includes an input unit 21, an X-ray image storage unit 22, a control unit 23, an X-ray image acquisition unit 24, a C-arm control unit 25, and an X-ray image generation unit 26.

[0015] The input unit 21 includes a control panel and foot switches, and receives input from the operator for various operations on the X-ray diagnostic device 100. The X-ray image storage unit 22 stores X-ray image data. The control unit 23 performs overall control of the X-ray diagnostic device 100. The X-ray image acquisition unit 24 controls the X-ray source 14, X-ray detector 15, and C-arm control unit 25 to collect X-ray images. The X-ray image acquisition unit 24 also sends the collected X-ray images to the X-ray image generation unit 26. The C-arm control unit 25 controls the rotation of the C-arm 13, etc., under the control of the X-ray image acquisition unit 24. The X-ray image generation unit 26 generates X-ray images.

[0016] Figure 3 shows the configuration of the X-ray diagnostic apparatus 100, measuring device 200, and ECG measuring device 300 according to the first embodiment. Figure 3 shows in detail some of the configurations of the X-ray diagnostic apparatus 100 shown in Figure 2 (configurations that analyze measurement data and X-ray images and display images and text characters), and the same parts are denoted by the same reference numerals and their descriptions are omitted. In addition, of the parts of the X-ray diagnostic apparatus 100 in Figure 3, all parts other than the display unit 16, input unit 21, X-ray image storage unit 22, and X-ray image acquisition unit 24 may be provided in the control unit 23 shown in Figure 2, etc.

[0017] The measuring device 200 and the ECG measuring device 300 can be realized using existing known technologies. First, the measuring device 200 measures intravascular pressure, calculates FFR and CFR based on the measurement data obtained, and transmits the calculated FFR and CFR to the X-ray diagnostic device 100 each time. Specifically, the intravascular pressure measuring unit 210 measures intravascular pressure, etc., and sends the measurement data to the physiological index calculation unit 211. The physiological index calculation unit 211 calculates FFR and CFR based on the measurement data and sends the calculated FFR and CFR to the physiological index transmission unit 212. The physiological index transmission unit 212 transmits the FFR and CFR to the X-ray diagnostic device 100. In addition to FFR and CFR, the physiological index transmission unit 212 may also transmit the measurement data itself measured by the intravascular pressure measuring unit 210 to the X-ray diagnostic device 100.

[0018] Furthermore, the ECG measurement device 300 measures the ECG and transmits the measured ECG to the X-ray diagnostic device 100 each time. Specifically, the ECG measurement unit 310 measures the ECG and sends the measured ECG to the ECG transmission unit 311. The ECG transmission unit 311 transmits the ECG to the X-ray diagnostic device 100.

[0019] The X-ray diagnostic device 100 associates a series of X-ray images taken during the measurement of the measurement data with the measurement data to identify the measurement location of the measurement data on the X-ray image, and displays the X-ray image indicating the measurement location on the display unit 16.

[0020] Specifically, the physiological indicator receiving unit 110 receives FFR and CFR from the measuring device 200 and stores them in the physiological indicator storage unit 111. The ECG receiving unit 112 receives ECG from the ECG measuring device 300 and stores it in the ECG storage unit 113. The time management unit 114 manages the correct time in the X-ray diagnostic device 100 and stores the communication time and image acquisition time in the communication / image acquisition time storage unit 115 each time it communicates with the measuring device 200 or the ECG measuring device 300, and each time the X-ray image acquisition unit 24 takes an X-ray image.

[0021] In the first embodiment, it is assumed that the X-ray diagnostic apparatus 100, the measuring device 200, and the ECG measuring device 300 are all correctly time-set. Therefore, the X-ray diagnostic apparatus 100 synchronizes the various information received from the measuring device 200 and the ECG measuring device 300 with the X-ray image taken by the X-ray diagnostic apparatus 100, according to the time managed by the time management unit 114. However, the embodiment is not limited to this, and for example, the X-ray diagnostic apparatus 100 may achieve temporal synchronization by transmitting a temporal synchronization signal to the measuring device 200 and the ECG measuring device 300.

[0022] Next, the specific unit 120 and the display control unit 130 will be described with reference to Figure 4. Figure 4 is a diagram illustrating the generation of a display image in the first embodiment.

[0023] The identification unit 120 identifies the acquisition location of blood flow indicators on an image including blood vessels collected by a medical imaging diagnostic device. Specifically, the identification unit 120 identifies the measurement location of the measurement data on an X-ray image collected by an X-ray diagnostic device 100. More specifically, the measurement time image extraction unit 121 extracts an X-ray image (measurement time image) corresponding to the time phase in which the measurement data was measured from a series of X-ray images taken by the X-ray image acquisition unit 24 and stored in the X-ray image storage unit 22. For example, the measurement time image extraction unit 121 uses time information corresponding to FFR and CFR received from the measurement device 200, time information corresponding to ECG received from the ECG measurement device 300, and time information corresponding to the X-ray image to associate these pieces of information collected at any given time. This enables temporal synchronization of information collected by different devices. The measurement time image extraction unit 121 then extracts an X-ray image having approximately the same time information as the time information corresponding to FFR or CFR as the X-ray image corresponding to the time phase in which the measurement data was measured, and sends the extracted X-ray image to the intravascular pressure measurement position identification unit 122.

[0024] The intravascular pressure measurement position identification unit 122 identifies the measurement position of the measurement data on the X-ray image (measurement time image) extracted by the measurement time image extraction unit 121. For example, the intravascular pressure measurement position identification unit 122 identifies the measurement position by performing image analysis on the X-ray image extracted by the measurement time image extraction unit 121 and identifying the tip of the guide wire used for measurement.

[0025] Identifying the tip of the guidewire can be achieved using existing known techniques. For example, the intravascular pressure measurement positioning unit 122 clarifies the guidewire image by performing enhancement processing on the X-ray image. For example, the intravascular pressure measurement positioning unit 122 reduces density unevenness in the X-ray image by performing nonlinear brightness conversion, and then applies image filtering processing to extract components with high spatial frequencies. This image filtering processing removes global and smooth gradations, leaving only local and fine fluctuation components. Next, the intravascular pressure measurement positioning unit 122 identifies the guidewire image by applying pattern extraction processing to the X-ray image. For example, the intravascular pressure measurement positioning unit 122 performs pixel value thresholding processing and spatial filtering processing. Then, the intravascular pressure measurement positioning unit 122 extracts the guidewire image from the X-ray image, obtains a two-dimensional curve that shows the shape of the guidewire image in the X-ray image, and extracts the coordinates of the guidewire tip located at the end of the two-dimensional curve based on the coordinate values ​​of each point on the two-dimensional curve.

[0026] The display control unit 130 displays the acquisition position on the image including blood vessels and displays an index on the display unit in association with the acquisition position. For example, the display control unit 130 displays the measurement position on the X-ray image and displays FFR and CFR in association with the measurement position. First, the heart rate one-cycle contrast-enhanced image group extraction unit 141 of the periodic image processing unit 140 extracts a group of contrast-enhanced images (still images) for one heart rate cycle in which the entire coronary artery is well contrast-enhanced, from the time-series X-ray image group stored in the X-ray image storage unit 22, as shown in Figure 4. For example, the heart rate one-cycle contrast-enhanced image group extraction unit 141 compares the brightness value distribution of each X-ray image and determines that the X-ray image group with low brightness values ​​is a group of contrast-enhanced images in which the coronary artery is well contrast-enhanced.

[0027] As shown in Figure 4, the coronary artery branch identification unit 142 extracts the coronary artery region from each contrast-enhanced image in the contrast-enhanced image group extraction unit 141, and identifies the coronary artery branch. For example, the coronary artery branch identification unit 142 extracts the coronary artery region from each contrast-enhanced image and identifies the coronary artery branch based on imaging conditions such as the angle of the C-arm 13, the brightness value of the pixels, their continuity, the shape of the blood vessel, and the amount of change between contrast-enhanced images of adjacent time phases. The identification of coronary artery branches can be achieved using existing known techniques.

[0028] The stenosis identification unit 143 identifies the stenotic site within the coronary artery region extracted by the coronary artery branch identification unit 142. For example, the stenosis identification unit 143 identifies the stenotic site based on the continuity of the vascular structure, particularly changes in the vessel diameter. The identification of the stenotic site can be achieved using existing known techniques.

[0029] The interphase coronary artery branch / stenosis site mapping unit 144 associates stenosis sites identified in each contrast-enhanced image of a group of contrast-enhanced images representing one heart cycle across different time phases. This allows tracking of the time-series displacement of stenosis sites on X-ray images. For example, the interphase coronary artery branch / stenosis site mapping unit 144 calculates a WarpField between contrast-enhanced images. A WarpField is a known image processing technique that performs nonlinear alignment. For example, the interphase coronary artery branch / stenosis site mapping unit 144 extracts features from each contrast-enhanced image and associates the extracted features across different time phases to calculate a collection of three-dimensional vectors indicating the amount of pixel movement.

[0030] As shown in Figure 4, the Measurement Data / Stenosis Site Mapping Unit 145 associates measurement data with stenosis sites identified on contrast-enhanced images (periodic images) based on the measurement location identified on the X-ray image (measurement time image) by the Intravascular Pressure Measurement Location Identification Unit 122. For example, the Measurement Data / Stenosis Site Mapping Unit 145 uses ECG to identify contrast-enhanced images (periodic images) from a group of contrast-enhanced images for one heart cycle that match the time phase of the measurement time image. Then, based on the measurement location identified on the X-ray image (measurement time image), the Measurement Data / Stenosis Site Mapping Unit 145 associates the FFR and CFR calculated from the measurement data measured at this location with the stenosis sites on contrast-enhanced images (periodic images) adjacent to this location. This allows the FFR and CFR to be displayed on each X-ray image included in the time-series X-ray image group.

[0031] Meanwhile, the heart rate cycle-corresponding image identification unit 151 of the display image processing unit 150 uses the ECG to identify which time phase in one heart rate cycle the display image selected by the display image selection unit 116 corresponds to. The display image selection unit 116 can, for example, receive instructions from the operator via the input unit 21 and appropriately select a display image from the time-series X-ray image group stored in the X-ray image storage unit 22. For example, in the first embodiment, the display image selection unit 116 displays a selection menu of X-ray images stored in the X-ray image storage unit 22 (for example, "Patient List" or "Examination List"), receives instructions from the operator via the input unit 21, and selects a single contrast-enhanced image (still image) as the display image.

[0032] The coronary artery branch identification unit 152 extracts the coronary artery region from the contrast-enhanced images of the time phase identified by the heart cycle-corresponding image identification unit 151, from the contrast-enhanced images extracted by the heart cycle-corresponding image identification unit 141, using the same method as the coronary artery branch identification unit 142, and identifies the coronary artery branch. The stenosis site identification unit 153 identifies the stenosis site within the coronary artery region extracted by the coronary artery branch identification unit 152, using the same method as the stenosis site identification unit 143.

[0033] As shown in Figure 4, the display image mapping unit 154 associates the measurement positions identified on the contrast-enhanced image (periodic image) with the display image. For example, the display image mapping unit 154 uses the WarpField calculated by the interphase coronary artery branch / stenosis site mapping unit 144 to identify (align) the position where the measurement positions identified on the contrast-enhanced image (periodic image) have moved in the temporal phase of the display image using a three-dimensional vector. The display image mapping unit 154 then identifies multiple measurement positions identified on contrast-enhanced images of different temporal phases on a single display image. In other words, by identifying the position where each measurement position has moved in the temporal phase of the display image using the WarpField, the display image mapping unit 154 corrects the discrepancy between the single contrast-enhanced image selected as the display image and each contrast-enhanced image in which each measurement position is identified.

[0034] The display image generation unit 155 generates a display image and displays it on the display unit 16. Figure 5 shows an example of the display in the first embodiment. As shown in Figure 5, in the first embodiment, the display image generation unit 155 displays the measurement position of the measurement data on an X-ray image (still image) of a predetermined time phase, and displays physiological evaluation indices (e.g., FFR and CFR) calculated from the measurement data in correspondence with the measurement position. The display image generation unit 155 also displays the stenosis rate in correspondence with each stenotic site, thereby displaying both anatomical and physiological evaluation indices on the same X-ray image. Furthermore, as shown in Figure 5, the display image generation unit 155 also displays information regarding the necessity of treatment (e.g., no treatment needed, treatment required). The mark indicating the stenotic site (a white circle in Figure 5) may be displayed in a different color depending on, for example, whether treatment is necessary or the stenosis rate. The text string and the frame surrounding the text string may also be displayed in a different color depending on, for example, whether treatment is necessary or the FFR or CFR values. For example, when something needs to be highlighted, it could be displayed in red.

[0035] The treatment necessity criteria setting unit 117 sets criteria for determining whether treatment is necessary. For example, the treatment necessity criteria setting unit 117 sets a criterion that "treatment is required if any of the following conditions are met: FFR < 0.75, CFR ≤ 2.00, or stenosis rate ≥ 50%." The treatment necessity determination unit 118 determines whether treatment is necessary based on the criteria set by the treatment necessity criteria setting unit 117. The determination result from the treatment necessity determination unit 118 is sent to the display image generation unit 155.

[0036] Figure 6 shows another display example in the first embodiment. As shown in Figure 6, in the first embodiment, the display image generation unit 155 may not only display various indicators around the stenosis (the display of various indicators is omitted in Figure 6), but may also display the blood vessel itself in color or shades according to measured values ​​such as intravascular pressure. In Figure 6, for convenience, it is shown as shades of color, but for example, it may be displayed as shades of red and yellow according to the measured values.

[0037] Figure 7 shows another display example in the first embodiment. As shown in Figure 7, in the first embodiment, the display image generation unit 155 may display a tool for manually adjusting the results of the automatic processing. That is, as described above, in the first embodiment, stenosis sites and measurement locations of measurement data are automatically identified and displayed on the X-ray image, but the display may not always show the expected results. For such cases, the display image generation unit 155 displays a UI (User Interface) as shown in Figure 7. This UI, for example, extracts the vascular core line from the coronary artery branch identified by the coronary artery branch identification unit 142 and displays the extracted vascular core line. The display image generation unit 155 accepts sliding operations of a bar a indicating the measurement position and a mark b indicating the stenosis site on this vascular core line. That is, since both the measurement position and the stenosis site should exist on the vascular core line (deviation from the core line within the vessel diameter is ignored), the display image generation unit 155 may provide a UI that can only be slid on the vascular core line.

[0038] As described above, according to the first embodiment, the measurement location of the measurement data is displayed on the vascular image, so the measurement location of the physiological indicator can be grasped on the vascular image. In this way, according to the first embodiment, the physiological evaluation results are displayed in relation to the anatomical evaluation results. As a result, the operator can easily grasp, for example, where in the coronary artery the physiological evaluation indicator was obtained, which is effective not only in the case of normal lesions but also in the case of continuous lesions and multi-vessel lesions.

[0039] Thus, according to the first embodiment, physiological evaluation indices linked to the location of stenosis can be displayed in real time on X-ray images taken during PCI (Percutaneous Coronary Intervention) or in past images stored on a workstation or the like. In addition, intravascular pressure and blood flow velocity values ​​measured to calculate the physiological evaluation indices can also be displayed at the measured location. As a result, the myocardial ischemia-inducing potential of coronary artery stenosis can be evaluated from both anatomical and physiological perspectives on a single image, and the procedure can be performed while displaying the necessity of treatment and the treatment status during PCI. Furthermore, if physiological evaluation values ​​are displayed on past examination images, they can be quantitatively compared with the current state from a physiological perspective.

[0040] (Second embodiment) In the second embodiment, the display image is assumed to be a series of X-ray images (moving images) captured in real time. Figure 8 is a diagram illustrating the generation of the display image in the second embodiment. In this case, the display control unit 130 uses an ECG to synchronize the contrast-enhanced images (periodic images) and the display image group in time, and displays the stenotic areas identified on the contrast-enhanced images (periodic images), as well as indices such as FFR and CFR, in the correct positions on the display image.

[0041] Specifically, the heart rate cycle-corresponding image identification unit 151 of the display image processing unit 150 uses ECG to identify which phase in one heart rate cycle each display image included in the time-series display image group corresponds to. The display image mapping unit 154, as shown in Figure 8, associates the measurement positions identified on the contrast-enhanced image (periodic image) with each display image included in the time-series display image group. For example, the display image mapping unit 154 uses the WarpField calculated by the inter-phase coronary artery branch / stenosis site mapping unit 144 to identify (align) the position where the measurement positions identified on the contrast-enhanced image (periodic image) have moved in each phase of the display image using a three-dimensional vector. The display image mapping unit 154 then identifies multiple measurement positions identified on contrast-enhanced images of different phases on their respective display images. Furthermore, when displaying images sequentially while measuring measurement data, the display control unit 130 should initially display one measurement position on the display image, and then gradually display two measurement positions, and then three measurement positions.

[0042] (Third embodiment) In the third embodiment, the display image is assumed to be a time-series X-ray image (moving image) captured in real time, and is a non-contrast image. Figure 9 is a diagram illustrating the generation of the display image in the third embodiment. In this case, since the display image is a non-contrast image, the coronary artery vascular structure is not displayed on the display image. Therefore, the display control unit 130 extracts structural information such as vascular contours from the contrast-enhanced image (periodic image) group and superimposes the extracted structural information onto the non-contrast display image group. Furthermore, since the display control unit 130 uses ECG to temporally synchronize the contrast-enhanced image (periodic image) group and the display image group, it is also possible to temporally synchronize the structural information with the display image, and the displacement and deformation of the blood vessels are reflected in the structural information as well.

[0043] Figure 10 shows an example of the display in the third embodiment. As shown in Figure 10, in the third embodiment, the display control unit 130 displays physiological evaluation indices, stenosis rate, and whether treatment is necessary on a non-contrast display image on which structural information such as blood vessel contours is superimposed, corresponding to the measurement location of the measurement data.

[0044] Figure 11 is a diagram showing another display example in the third embodiment. As shown in Figure 11, in the third embodiment, the display control unit 130 may not only display various indicators around the stenosis on the non-contrast display image (the display of various indicators is omitted in Figure 11), but may also display the blood vessel itself in color or grayscale in real time according to measured values ​​such as intravascular pressure.

[0045] Here, we will describe one use case of the X-ray diagnostic device 100 as a medical imaging diagnostic device according to the present application. As mentioned above, various indicators are used as indicators related to blood flow, and these indicators are used, for example, for the early detection of vascular stenosis in the myocardial region that causes myocardial infarction. To give one example, the presence or absence of vascular stenosis is determined by evaluating the reduction in blood flow caused by the stenosis, and if the FFR value (hereinafter referred to as FFR value) is below the standard value, that location is determined to be a stenosis.

[0046] Previously, determining the presence or absence of vascular stenosis involved the operator manipulating a guidewire while viewing a real-time display of X-ray images (e.g., fluoroscopic images) of the subject with a pressure sensor-equipped guidewire inserted into the blood vessel, acquired by an X-ray diagnostic device. Simultaneously, the operator viewed a display showing the FFR value calculated from the subject's pressure measured by the pressure sensor. However, because the FFR value and the location in the blood vessel where the pressure used to calculate the FFR value was measured were not correlated, even if the operator determined a stenosis based on the FFR value, it was not intuitively clear where in the blood vessel that it was located.

[0047] Therefore, by applying the technology of this application to such cases, the spatial visibility of indicators useful for diagnosing vascular stenosis is improved. The X-ray diagnostic device 100 related to this use case will be described below with reference to Figures 12 to 26. An indicator useful for diagnosing vascular stenosis is an indicator representing blood flow, and here the FFR value will be explained as a specific example. The FFR value is given as the ratio of the pressure at an arbitrary point in the target blood vessel to the pressure at a point in the aorta (blood flow pressure). The pressure is measured by a pressure sensor 210a attached near the tip of the guidewire. In this use case, the guidewire is inserted into the blood vessel under non-contrast fluoroscopic imaging. Fluoroscopic images are repeatedly collected at a constant period of 1 / 30 sec or so under continuous X-rays under fluoroscopic X-ray conditions (relatively low dose). The X-ray image taken under this fluoroscopic conditions with operator triggering using pulsed X-rays under imaging X-ray conditions (relatively high dose) is called the acquired image. The images acquired while highlighting blood vessels with a contrast agent are the contrast-enhanced images described above, and include, for example, DA images (digital angiography images) and DSA (digital subtraction angiography) images, which are obtained by taking the difference between DA images before and after contrast agent injection to make the blood vessels clearer.

[0048] As shown in Figure 12, the X-ray diagnostic apparatus 100a comprises a gantry unit 10a and a computer system 20a. The gantry unit 10a has a C-arm 13a supported by a gantry unit 12a, as shown in Figure 13. In addition, the gantry unit 10a includes a C-arm control unit 25a, an X-ray source 14a, an X-ray detector 15a, and a high-voltage generator 17a. The gantry unit 10a is also called the gantry unit. The computer system 20a is also called the system body. The gantry unit 12a is also called the C-arm support mechanism. The C-arm 13a is also called the C-arm. The C-arm control unit 25a is also called the rotation drive unit. The X-ray source 14a is also called the X-ray tube unit. The X-ray detector 15a is also called the X-ray detection unit.

[0049] The computer system 20a includes an input unit 21a, a control unit 23a, an X-ray image acquisition unit 24a, an X-ray image generation unit 26a, and an image processing device 30. The input unit 21a is also called the operation unit. The control unit 23a is also called the system control unit. The X-ray image acquisition unit 24a is also called the imaging control unit. The X-ray image generation unit 26a is also called the image generation unit. The image processing device 30 includes an X-ray image storage unit 22a, an FFR value storage unit 111a, an FFR value input unit 110a, an image processing control unit 31, a position identification unit 120a, an FFR value selection unit 32, a mark generation unit 33, a display control unit 130a, and a display unit 16a. An external FFR value measuring device 200a is connected to the computer system 20a via the FFR value input unit 110a.

[0050] The FFR value storage unit 111a is an example of the physiological indicator storage unit 111 described above. The FFR value input unit 110a is an example of the physiological indicator receiving unit 110 described above. The location identification unit 120a is an example of the identification unit 120 described above.

[0051] The control unit 23a comprehensively controls the operation of the entire apparatus, such as the imaging operation and the image processing operation. The X-ray imaging unit 24a controls the high-voltage generation unit 17a, the X-ray detector 15a, the X-ray image generation unit 26a, and the C-arm control unit 25a in order to perform imaging operations in accordance with the operator's instructions input via the input unit 21a.

[0052] The input unit 21a functions as a man-machine interface for the operator to input instructions to the X-ray diagnostic device 100a. For example, the input unit 21a has a trackball, various switches, buttons, a mouse, a keyboard, a foot pedal, a touch panel, etc., for receiving various instructions, conditions, region of interest (ROI) setting instructions, various image quality conditions, and imaging (fluoroscopy) condition setting instructions from the operator into the device. The input unit 21a may also be equipped with a wireless receiver and a wireless processing unit so that the operator can operate it from a remote location.

[0053] The frame 12a supports the C-arm 13a so that it can rotate independently with respect to three orthogonal axes. The C-arm control unit 25a generates power to rotate the C-arm 13a based on the control of the X-ray imaging unit 24a. The C-arm 13a has an X-ray source 14a mounted at one end. The X-ray source 14a consists of an X-ray tube that generates X-rays when a high voltage is applied from a high voltage generator 17a, and an X-ray diaphragm attached to the X-ray irradiation window of the X-ray tube to limit the X-ray irradiation field. The C-arm 13a has an X-ray detector 15a mounted at the other end. The X-ray detector 15a is mounted facing the X-ray source 14a. The X-ray detector 15a is a two-dimensional, typically flat panel detector (FPD), that detects X-rays that have passed through the subject.

[0054] The X-ray image generation unit 26a generates a two-dimensional spatial distribution of transmitted X-ray intensity, i.e., a two-dimensional X-ray image, based on the output from the X-ray detector 15a. The image processing control unit 31 receives control signals from the control unit 23a and controls the components related to the image processing operation of the X-ray diagnostic device 100a in particular. The X-ray image storage unit 22a stores the X-ray images generated by the X-ray image generation unit 26a. For example, the X-ray image generation unit 26a stores fluoroscopic image data and contrast-enhanced image data (e.g., DA images). Hereinafter, a DA image will be used as an example of a contrast-enhanced image. Here, the fluoroscopic image data and the DA image data are stored associated with the corresponding X-ray generation time code and the heart rate phase code at the time of X-ray generation. Then, the operator selects a specific DA image as a reference image from among the multiple DA images stored in the X-ray image storage unit 22a.

[0055] The positioning unit 120a selects a live image with the same heart rate phase as the subject's heart rate phase (reference phase) at the time of reference image acquisition as the processing target, and identifies the sensor position on the reference image (DA image) from the sensor position on the selected live image. The current guidewire tip region is represented by a characteristic brightness in the live image. First, the positioning unit 120a extracts the guidewire tip region on the live image by thresholding. Then, the positioning unit 120a identifies the tip position from the shape characteristics or direction of movement of the extracted tip region. Furthermore, the positioning unit 120a identifies the sensor position on the live image by shifting the guidewire tip position backward by a distance specific to the guidewire, that is, the distance L (see Figure 26) from the guidewire tip position to the mounting position of the guidewire pressure sensor 210a.

[0056] Next, the position identification unit 120a identifies the sensor position on the reference image that corresponds to the sensor position on the live image of the current frame. First, the position identification unit 120a calculates the direction and distance of the sensor position identified on the live image of the current frame relative to the sensor position identified on the live image of the previous frame, using the sensor position identified on the live image of the previous frame as a reference. Then, using the calculated direction and distance, the position identification unit 120a identifies the sensor position on the reference image that corresponds to the sensor position on the live image of the current frame by displacing the previous sensor position on the reference image by the calculated distance and in the calculated direction. The initial sensor position on the reference image is set by the operator specifying the reference image. The sensor positions on the second and subsequent reference images are identified according to the displacement (direction and distance) of the sensor position on the live image from the sensor position on the previous reference image, and by repeating this in order, the movement trajectory of the sensor position on the reference image is identified.

[0057] The FFR value input unit 110a functions as an interface to an external FFR value measuring device 200a. The FFR value measuring device 200a measures the FFR value (partial myocardial flow reserve) as an indicator of blood flow. Depending on the degree of the FFR value, it is classified into three categories: treatment required, need to be determined, and no treatment required. The FFR value measuring device 200a consists of a pressure sensor 210a and an FFR value calculation unit 211a. The FFR value is calculated by the ratio of pressure measurements at each position in the blood vessel to the reference aortic pressure. Pressure measurements at each position in the blood vessel are measured by the pressure sensor 210a attached to a guidewire. The FFR value calculation unit 211a calculates the FFR value by dividing the pressure measurements at each position in the blood vessel measured by the pressure sensor 210a by the aortic pressure measurement measured by the pressure sensor 210a. The FFR value data is output with a code representing the measurement time of the pressure measurements at each position in the blood vessel by the pressure sensor 210a.

[0058] The FFR value storage unit 111a stores data of multiple FFR values ​​input via the FFR value input unit 110a. Each of the multiple FFR value data is associated with a code representing the measurement time of the pressure measurement value at each intravascular location by the pressure sensor 210a. The FFR value selection unit 32 selects an FFR value at the same time as or closest to the timing of the occurrence of the reference phase by referring to the measurement time code.

[0059] The mark generation unit 33 determines a mark having a color corresponding to the FFR value selected by the FFR value selection unit 32. The mark has a roughly rectangular shape with a width corresponding to the standard vessel diameter of the target vessel. The display control unit 130a cumulatively overlays the marks generated by the mark generation unit 33 onto the reference image stored in the X-ray image storage unit 22a. The display unit 16a displays the reference image with the cumulatively overlaid marks generated by the display control unit 130a.

[0060] Figure 14 shows the fluoroscopy procedure of this embodiment, along with the procedures for guidewire and contrast agent injection. The general sequence of operations according to this embodiment is as follows: (1) A dynamic image of the blood vessel is collected with a contrast agent injected through a catheter inserted into the blood vessel of the subject. Typically, digital angiography (DA) is used as the X-ray imaging technique at this time. (2) From the DA images collected repeatedly in (1), the frame in which the subject's FFR target area is best contrast-enhanced is displayed as a still image (reference image) on the reference monitor. (3) The FFR measurement target area is specified on the reference image according to the operator's instructions. (4) A guidewire with a pressure sensor is inserted to the target site within the FFR measurement target area. (5) While withdrawing the guidewire, the pressure (FFR value) is repeatedly measured via the pressure sensor. (6) The measured FFR values ​​are superimposed on the reference image, color-coded according to thresholds.

[0061] During the withdrawal period described in (5) above, the FFR value is repeatedly measured by the FFR value measuring device 200a. Typically, the measurement cycle for the FFR value is shorter than the frame cycle during X-ray fluoroscopy. The implantation period and the withdrawal period may be continuous, or they may be temporally separated with an interruption in X-ray fluoroscopy.

[0062] Figure 15 is a flowchart showing the procedure from catheter insertion to the completion of DA image acquisition. First, based on instructions from the operator via the input unit 21a, the gantry unit 10a is moved to a position where the desired vascular region of the subject can be observed, and the X-ray fluoroscopy conditions and image acquisition conditions are determined. Next, triggered by an operation by the operator using the mouse or buttons on the input unit 21a, the X-ray fluoroscopy operation is started under the control of the control unit 23a, and a fluoroscopic image is acquired (S11). The X-ray fluoroscopy conditions use a lower X-ray dose than, for example, X-ray imaging for acquiring mask images or contrast images. The fluoroscopic image is immediately displayed on the display unit 16a.

[0063] Under X-ray fluoroscopy, the operator inserts the catheter to the target position (S12). Next, the DA imaging technique is selected and DA imaging is performed. At this time, contrast agent is injected from an injector synchronized with the X-ray diagnostic device 100a, contrast-enhanced images are repeatedly collected, and the area in which FFR measurement should be performed is specified (S13). DA images are obtained using high-dose pulsed X-rays and are usually repeated several times at arbitrary timings. The data for each DA image is stored in the X-ray image storage unit 22a, associated with a code representing the DA image acquisition time and data on the subject's heart rate phase at the time of acquisition. The heart rate phase data is supplied from an external electrocardiograph (not shown) connected to the X-ray diagnostic device 100a.

[0064] Multiple DA images are displayed in a list on the display unit 16a under the control of the display control unit 130a, and one image suitable for stenosis diagnosis is selected as a reference image according to the operator's instructions (S14). As illustrated in Figure 16, the heart rate phase corresponding to the reference image is described as "AA%". The reference image may be selected according to the operator's criteria, such as an image with low noise or an image in which the vascular region is in the center of the image, or the X-ray diagnostic device 100a may have a function to calculate the brightness and noise of the image and select it automatically.

[0065] Next, the pressure sensor-equipped guidewire is manipulated to move the pressure sensor 210a, which is attached to the tip of the guidewire, to the target position within the blood vessel (the position determined by the operator on the DA image) and then implanted.

[0066] The position (initial position) of the pressure sensor 210a is specified by the operator's mouse operation on the enlarged reference image displayed on the display unit 16a, and the initial sensor position on the reference image is registered (S15). The registered initial sensor position data is stored in the X-ray image storage unit 22a along with the reference image data. Note that the registered position only needs to be stored by the X-ray diagnostic device 100a as coordinates based on any point on the image or reference image, and the registered position may or may not be displayed on the reference image.

[0067] Figure 17 is a flowchart showing the processing procedure during the guidewire withdrawal period in Figure 14. During this withdrawal period, X-ray fluoroscopy is performed by the control unit 23a, following the insertion period (S31). The execution of X-ray fluoroscopy generates fluoroscopic images (live images) repeatedly at regular intervals. The live image data is stored in the X-ray image storage unit 22a, associated with a code representing the image generation time and data on the subject's heart rate phase at the time of image generation. During the withdrawal period, the pressure sensor 210a moves from the implantation position in accordance with the guidewire withdrawal operation. The guidewire is gradually withdrawn by the operator's operation, and during this time, the FFR value is repeatedly measured by the FFR value measuring device 200a according to the output of the pressure sensor 210a (S32). The FFR value data is stored in the FFR value storage unit 111a, associated with a code representing the measurement time and data on the subject's heart rate phase at the time of measurement.

[0068] In step S33, the image processing control unit 31 determines each time a live image is generated whether its heart rate phase matches the heart rate phase (AA%) of the reference image, or whether it falls within a 5% range before or after the heart rate phase (AA%). For convenience, the former will be explained here. The data of the live image generated at a timing that matches the heart rate phase (AA%) of the reference image is read from the X-ray image storage unit 22a by the image processing control unit 31 and supplied to the position identification unit 120a. In the position identification unit 120a, the tip region of the guidewire is extracted from the supplied live image by threshold processing (S34). The sensor position is identified from the extracted tip region (S35). The pressure sensor 210a is mounted at a position behind the tip of the guidewire, at a distance L specific to the guidewire. For example, the sensor position is identified by correcting the distance L along the central axis of the guidewire from the extracted tip region of the guidewire.

[0069] As shown in Figures 18 and 19, the position identification unit 120a calculates the direction and distance of the sensor position An identified on the live image Pin for the current heart rate phase (AA%) relative to the sensor position An-1 identified on the live image Pin-1 for the previous heart rate phase (AA%) (S36).

[0070] Next, the sensor position on the current reference image is determined based on the calculated direction and distance, as well as the sensor position on the previous reference image (S37). In other words, as shown in Figure 20, the sensor position Bn on the current reference image is determined to be the position obtained by displacing the sensor position Bn-1 on the previous reference image according to the calculated direction and distance. The initial sensor position B1 on the reference image is manually specified by the operator.

[0071] By continuously identifying the sensor position on the reference image according to the direction and distance calculated from the previous and current sensor positions identified on the live image, starting from the sensor position on the reference image identified previously, it is possible to suppress the expansion of the discrepancy between the sensor position on the reference image and the sensor position on the live image. The main causes of this discrepancy are the movement of the subject itself due to the temporal separation between the acquisition of the reference image and the generation of the live image, and the change in the anatomical position of the same part due to fluctuations in the heart rate cycle, even if the heart rate phase is the same.

[0072] Next, marks with colors corresponding to the FFR value measured at the time of occurrence of the live image processed in this instance, or the closest time, are superimposed on the reference image at the sensor position identified in S37 (S38). Since the FFR value is calculated from the ratio of the pressure measurement value to the aortic pressure value, it is generally given as a value between 0 and 1. The FFR value from 0 to 1 is divided into multiple intervals, and a hue is pre-assigned to each interval.

[0073] Steps S31-S38 are repeated via step S39 until the end of the fluoroscopy process, during which the marks generated one after another are cumulatively superimposed on the reference image.

[0074] Figure 21 shows a time chart illustrating the repetition of this process S31-S38. During the withdrawal period, the reference image DAref is displayed continuously, and marks M1, M2, M3... in colors corresponding to the same-phase AA% FFR values ​​k1, k2, k3... are cumulatively superimposed on the reference image DAref at their respective sensor positions B1, B2, B3... according to the repetition of the heart rate cycle. As shown in Figure 22, the reference image is displayed on the same screen along with the fluoroscopic image (live image) and the time chart of the FFR values.

[0075] As described above, this use case allows the measurement location of indicators such as FFR values, which are useful for diagnosing vascular stenosis, to be confirmed on the reference image, thereby improving the spatial visibility of FFR values ​​and enhancing their usefulness. In other words, with this embodiment, the FFR value can be displayed as a mark on the X-ray image of a subject into which a guidewire equipped with a pressure sensor 210a has been inserted, superimposed on the location of the blood vessel where the pressure used to calculate the FFR value was measured. This allows for intuitive confirmation of the FFR value on the blood vessel, and is expected to improve the accuracy of measurement of vascular stenosis by the operator. Furthermore, in this embodiment, the sensor position on the reference image is continuously identified from the previously identified sensor position on the reference image according to the direction and distance calculated from the previous and current sensor positions identified on the live image. This suppresses the expansion of the discrepancy between the actual FFR measurement location (the sensor position on the live image) and the displayed sensor position on the reference image.

[0076] Furthermore, the display method of the FFR value on the reference image can be varied in various ways. For example, as shown in Figure 23, when the operator performs a specific operation on the input unit 21a at any time during FFR value measurement, the FFR value at that time may be displayed numerically in a callout at the sensor position on the reference image at that time. Also, as shown in Figure 24, it may be possible to switch the target of the superimposed mark display from the reference image to the live image (transparent image). Moreover, as shown in Figure 25, it may be possible to switch the numerical display of the FFR value from the reference image to the live image (transparent image) and superimpose it.

[0077] Furthermore, the above-described embodiment explained the case in which fluoroscopic images are repeatedly acquired at a constant period of 1 / 30 sec or so under continuous X-rays. However, the embodiment is not limited to this, and the fluoroscopic images may be acquired when X-rays are irradiated at a constant time interval. In such a case, fluoroscopic images are acquired at a constant time interval while the guide wire is gradually withdrawn by the operator. The display control unit 130a then displays a mark on the reference image or on the fluoroscopic image at the sensor position at the time the fluoroscopic image was acquired. Note that the FFR value may be measured repeatedly by the FFR value measuring device 200a according to the output of the pressure sensor 210a, or it may be measured in accordance with the timing of the fluoroscopic image. This can reduce the amount of radiation exposure to the subject.

[0078] (Fourth embodiment) In the fourth embodiment, the treatment status is further displayed. Figure 27 is a block diagram showing the configuration of the X-ray diagnostic apparatus 100 according to the fourth embodiment. As shown in Figure 27, the X-ray diagnostic apparatus 100 according to the fourth embodiment further comprises components for displaying and updating the treatment status in real time.

[0079] The guidewire tip position tracking unit 161 identifies the guidewire tip position in real time within the X-ray image acquired in real time. Similar to the intravascular pressure measurement position identification unit 122, existing known techniques can be used to identify the guidewire tip position.

[0080] The stenosis site stent detection unit 162 extracts treatment devices corresponding to the stenosis site, such as stents and balloons, from the X-ray image. For example, the stenosis site stent detection unit 162 performs image analysis based on the tip position of the guidewire identified by the guidewire tip position tracking unit 161 and extracts the treatment device. Similar to the intravascular pressure measurement position identification unit 122, existing known techniques can be used for this extraction of treatment devices, but it is necessary to recognize the shape of the treatment device and extract it from the image.

[0081] The treatment status determination unit 163 determines the treatment status based on whether or not a treatment device has been placed in the stenotic area on the image. For example, if the treatment status determination unit 163 determines that a treatment device has been placed as a result of detection by the stenotic area stent detection unit 162, it determines that the treatment is complete. On the other hand, if the treatment status determination unit 163 determines that a treatment device has not been placed, it determines that the treatment is untreated.

[0082] Figure 28 shows an example of the display in the fourth embodiment. In the fourth embodiment, the display control unit 130 further displays information indicating the treatment status (such as "treated" or "not treated") according to the determination result by the treatment status determination unit 163, as shown in Figure 28.

[0083] (Fifth embodiment) In the fifth embodiment, information predicting improvement in myocardial ischemia associated with treatment is further displayed. Figure 29 shows the configuration of the X-ray diagnostic device 100, measuring device 200, and ECG measuring device 300 according to the fifth embodiment. As shown in Figure 29, the X-ray diagnostic device 100 according to the fifth embodiment further includes parts for predicting improvement in myocardial ischemia in real time in conjunction with treatment of the stenotic area and displaying the predicted results.

[0084] The ischemia analysis image storage unit 164 stores ischemia analysis result images such as myocardial perfusion. For example, ischemia analysis result images are CT (Computed Tomography) images or combined images of CT images and SPECT (Single Photon Emission Computed Tomography) images, and are images taken by an X-ray CT device or SPECT device. In the fifth embodiment, it is assumed that alignment has already been completed between the X-ray image taken by the X-ray diagnostic device 100 and the ischemia analysis result image stored in the ischemia analysis image storage unit 164. This alignment can be achieved using existing known techniques, for example, based on information such as the shooting conditions such as the angle of the C-arm 13, the brightness distribution of the Ray-Sum image (sum value projection image), and the shape of the heart and coronary arteries.

[0085] The ischemia-inducing estimation unit 165 estimates the ischemia-inducing potential, which indicates the degree to which ischemia is induced by stenosis. For example, the relationship between which coronary arteries supply which myocardial regions is anatomically known. Therefore, the ischemia-inducing estimation unit 165 calculates the ischemia-inducing potential (e.g., induction rate) for each location within the ischemic myocardium, based on the relationship between the FFR of a stenosis on a coronary artery supplying a certain myocardial region and the extent and degree of ischemia in that myocardial region.

[0086] FFR is information received from the measuring device 200, and the extent and degree of ischemia are information obtained from the ischemia analysis result image. For example, if there are multiple stenotic sites in a single coronary artery, the ischemia-inducing potential estimation unit 165 can calculate the induction rate by weighting the multiple FFRs. The ischemia-inducing potential estimation unit 165 has pre-learned an algorithm that calculates ischemia-inducing potential from the relationship between FFR and the extent and degree of ischemia, and calculates ischemia-inducing potential by inputting this information into this algorithm.

[0087] The ischemia improvement prediction unit 166 uses the ischemia-inducing potential estimated by the ischemia-inducing potential estimation unit 165 to predict in real time the improvement of myocardial ischemia associated with treatment of the stenotic site. In cases of multi-vessel disease or multiple lesions, treatment is carried out sequentially starting with the stenotic site with the highest ischemia-inducing potential, but the treatment results may not reach the expected improvement in ischemia. To evaluate these treatment results during treatment, in the fifth embodiment, the FFR is measured each time the stenotic site is treated, and the ischemia-inducing potential estimation unit 165 recalculates the ischemia-inducing potential using the remeasured FFR.

[0088] The ischemia improvement prediction unit 166 calculates the difference between the ischemia-inducing factor calculated before treatment and the ischemia-inducing factor calculated after treatment for each location within the ischemic myocardium, and predicts the improvement of myocardial ischemia at each location within the ischemic myocardium. The display control unit 130 further displays the ischemia analysis result image along with the X-ray image, and also displays the prediction result (i.e., the predicted degree of improvement) on the ischemia analysis result image.

[0089] Figure 30 is a diagram illustrating the prediction of myocardial ischemia improvement in the fifth embodiment. The graph of signal values ​​shown in Figure 30 shows the signal values ​​of ischemia analysis results such as myocardial perfusion. These signal values ​​are analyzed from parameters such as contrast agent arrival peak time (TTP (Time To Peak)), myocardial blood volume (MBV (Myocardial Blood Volume)), and mean transit time (MTT (Mean Transit Time)). The display control unit 130 displays contour lines showing the percentage of ischemia improvement associated with the change in FFR from '0.50' to '0.90' due to treatment of stenosis 1, for example, as shown in Figure 30.

[0090] Figure 31 shows an example of the display in the fifth embodiment. In the fifth embodiment, as shown in Figure 31, in addition to the X-ray image on which measurement data and other information are superimposed, the ischemia analysis result image is also displayed on the display unit 16. The display control unit 130 then displays contour lines c on the ischemia analysis result image before treatment, for example, as shown in Figure 31. In the fifth embodiment, contour lines c are lines drawn according to the magnitude of the difference before and after treatment. For example, the display control unit 130 may assign a darker color when the difference before and after treatment is large, and a lighter color when the difference before and after treatment is small. Furthermore, the embodiment is not necessarily limited to contour lines; for example, the color may be changed on a pixel-by-pixel basis for display.

[0091] In this way, by displaying the prediction of improvement on the ischemia analysis result image, those involved in treatment can visually confirm the extent and degree of ischemia improvement. Since complex screen operations are difficult during catheterization procedures, efficient evaluation is possible. For example, if the FFR value increases following treatment of the stenotic site, it indicates that the extent and degree of myocardial ischemia associated with that stenotic site will improve.

[0092] (Other embodiments) Furthermore, the embodiments are not limited to those described above, and can be implemented in various other different forms.

[0093] In the embodiments described above, the case in which measured indicators are used as indicators related to blood flow was explained. However, the embodiments are not limited to this, and for example, simulation indicators such as CT-FFR may be used. Figure 32 is a diagram showing the generation and display examples of display images in other embodiments. For example, as shown in Figure 32, the control unit 23 in the X-ray diagnostic device 100 generates a three-dimensional vascular model based on CT volume data at the time of the initial diagnosis. The control unit 23 then calculates the FFR value at each position in the generated three-dimensional vascular model. The calculation of the FFR value at each position in the three-dimensional vascular model can be achieved using existing known techniques.

[0094] Then, as shown in Figure 32, the display control unit 130 displays the calculation position of the FFR value calculated by the control unit 23 on the X-ray image (contrast-enhanced or non-contrast-enhanced image) of the same subject from which the CT volume data was collected, and displays the calculated FFR value (CT-FFR: 0.7 in the figure) corresponding to the calculation position. Here, the X-ray diagnostic device in this application is capable of processing 4D data. That is, the control unit 23 generates a three-dimensional vascular model from each of the CT volume data collected over time and calculates the FFR value for each position.

[0095] The display control unit 130 then uses ECG to identify volume data corresponding to the time phase of each X-ray image in a series of continuously acquired X-ray images (contrast-enhanced or non-contrast-enhanced images), and displays the FFR value calculated using the identified volume data, corresponding to the calculation position on the X-ray image. This makes it possible to understand the FFR value at each position in each time phase of multiple X-ray images before actually measuring it. Furthermore, as shown in Figure 32, when various indicators are actually measured during treatment, the display control unit 130 simultaneously displays the measured values ​​"FFR: 0.8, CFR: 4.00" in addition to the simulation result "CT-FFR: 0.7" from the time of diagnosis. This makes it easy to compare the simulation value with the measured value, enabling more efficient subsequent diagnoses.

[0096] In the embodiments described above, an X-ray diagnostic device 100 was used as an example of a medical imaging diagnostic device, but the embodiments are not limited to this. The same can be applied to other medical imaging diagnostic devices such as ultrasound diagnostic devices, magnetic resonance imaging devices, and nuclear medicine imaging devices. It may also be applied to an image processing device other than a medical imaging diagnostic device. In this case, for example, the image processing device receives various information from a measuring device or a medical imaging diagnostic device, or accepts input from an operator, and uses this information to perform processing similar to that of the specific unit 120 and the display control unit 130 described above. Here, the image processing device is, for example, a workstation, a PACS (Picture Archiving and Communication System) image server or viewer, or various devices of an electronic medical record system. It may also be applied to a measuring device (blood pressure monitor) different from a medical imaging diagnostic device and an image processing device. In such a case, for example, the measuring device has a monitor for displaying images. The measuring device receives various information from a medical imaging diagnostic device, or accepts input from an operator, and uses this information to perform processing similar to that of the specific unit 120 and the display control unit 130 described above. In this context, blood pressure monitors include, for example, central peripheral venous blood pressure monitors.

[0097] Furthermore, the embodiments are not limited to those described above, and various configurations can be combined as appropriate. First, the synchronization with the capture of the display image can be in real time (displaying the measurement position on the image being captured), offline (displaying the measurement position on a pre-collected image), or synchronized with images stored in another device (e.g., a workstation). In addition, the display image can be a 2D image, a time-series 2D image, a 3D image, or a 4D image. In addition, the display image can be a contrast-enhanced image, a non-contrast image, or an image in the process of contrast enhancement (including an image that is not completely contrast-enhanced). In addition, the images to be processed can be X-ray images, CT images, SPECT images, or images collected by other medical imaging diagnostic devices. In addition to the image analysis described above, methods for determining the treatment status can include detecting changes in intravascular pressure or having the operator input the treatment status. Furthermore, methods for temporally synchronizing various information received from the measuring device 200, etc., with X-ray images include simply synchronizing at each individual time point, and methods that do not synchronize the entire time period for which the data is stored, but rather extract only the time period around the time when the internal pressure around the stenosis was measured and synchronize that period.

[0098] Furthermore, while the embodiments described above used FFR and CFR as examples of blood flow indicators, the embodiments are not limited to these. For example, other indicators customized from these may also be used.

[0099] Furthermore, while the above-described embodiment assumes that the shooting direction of the C-arm is fixed, the embodiment is not limited to this. The various processes described above can be repeated in accordance with the change in the shooting direction of the C-arm.

[0100] Furthermore, although the above-described embodiment assumes the coronary artery, the embodiment is not limited to this and can be similarly applied to other blood vessels.

[0101] According to the image processing apparatus, medical image diagnostic apparatus, and blood pressure monitor of at least one embodiment described above, the measurement locations of physiological indicators can be identified on the vascular image. (Note 1) The identification unit identifies the location of acquisition of blood flow indicators on an image including blood vessels collected by a medical imaging diagnostic device, A display control unit that displays the acquisition position on the image including the blood vessel, and displays the index on the display unit in correspondence with the acquisition position. An image processing apparatus characterized by comprising: (Note 2) The identifying unit identifies the acquisition position of each of the multiple indicators acquired sequentially at different time phases on an image including blood vessels corresponding to the time phase at which they were acquired. The image processing apparatus according to Appendix 1, characterized in that the display control unit further identifies the corresponding position on an image containing blood vessels at a predetermined time phase for each acquisition position identified on an image containing blood vessels corresponding to the time phase at the time of acquisition, and displays each index in association with each identified position. (Note 3) The image processing apparatus according to Note 2, characterized in that the display control unit calculates the amount of pixel movement between images of different time phases, and uses the calculated amount of movement to further identify the corresponding position on an image containing blood vessels of a predetermined time phase for each acquisition position. (Note 4) The image processing apparatus according to any one of Notes 1 to 3, characterized in that the identifying unit extracts an image containing blood vessels corresponding to the time phase at the time of acquisition from a time-series image group containing blood vessels collected by the medical image diagnostic device, and identifies the acquisition position by identifying the tip of the instrument used for acquisition through image analysis of the extracted image containing blood vessels. (Note 5) The image processing apparatus according to any one of Notes 1 to 4, characterized in that the display control unit displays the index on the display unit in association with an acquisition position identified on an image including blood vessels that has been collected in advance by a medical image diagnostic device, or an acquisition position identified on an image including blood vessels that has been collected in real time by a medical image diagnostic device. (Note 6) The image processing apparatus according to any one of Notes 1 to 5, characterized in that when the display control unit displays the acquired position on an image including non-contrast vessels, it superimposes structural information extracted from an image including contrast-enhanced vessels onto the image including non-contrast vessels. (Note 7) The system further includes a treatment necessity determination unit that determines whether treatment of the stenotic area is necessary based on the blood flow indicators mentioned above. The image processing apparatus according to any one of the appendices 1 to 6, characterized in that the display control unit further displays the determination result of whether or not treatment is necessary on the display unit in correspondence with the acquisition position. (Note 8) The system further includes a treatment status determination unit that determines the treatment status by analyzing the image including the blood vessels, The image processing apparatus according to any one of appendices 1 to 7, characterized in that the display control unit further displays the determination result of the treatment state on the display unit in correspondence with the acquisition position. (Note 9) The system further includes a prediction unit that predicts the improvement of ischemia associated with treatment based on the aforementioned blood flow indicators, The image processing apparatus according to any one of the appendices 1 to 8, characterized in that the display control unit further displays an image indicating the degree of ischemia along with the image including the blood vessels on the display unit, and further displays the prediction result on the image indicating the degree of ischemia. (Note 10) The identification unit identifies the position of a pressure sensor inserted into the subject via a guide wire using threshold processing from each of a plurality of fluoroscopic images selected from a series of fluoroscopic images of the subject, and identifies the position of the subject on the captured image corresponding to the identified position of the pressure sensor based on the displacement of the position of the pressure sensor on the fluoroscopic image. The image processing apparatus according to Appendix 1, characterized in that the display control unit causes the display unit to overlay marks representing indicators derived from the output of the pressure sensor onto the captured image according to the specified positions on the captured image. (Appendix 11) The image processing apparatus according to Appendix 10, further comprising a selection unit for selecting a transparent image to be used to identify the position of the pressure sensor from the series of transparent images. (Note 12) The image processing apparatus according to Note 11, wherein the selection unit selects a fluoroscopic image from the series of fluoroscopic images to be used for identifying the position of the pressure sensor, based on the heart rate phase at the time the captured image was taken. (Note 13) The image processing apparatus according to Note 12, wherein the selection unit selects a fluoroscopic image generated at a timing substantially the same as the heart rate phase at the time of capturing the captured image as the fluoroscopic image to be used to identify the position of the pressure sensor. (Note 14) The mark is an image processing apparatus as described in Note 10, having a color corresponding to the indicator. (Note 15) The mark is cumulatively superimposed on the captured image, as described in Note 10. (Note 16) The imaging unit photographs the subject and collects images including blood vessels, A unit for identifying the location for acquiring blood flow indicators on the image including the blood vessels, A display control unit that displays the acquisition position on the image including the blood vessel, and displays the index on the display unit in correspondence with the acquisition position. A medical imaging diagnostic device characterized by being equipped with [a specific feature]. (Note 17) Means for obtaining indicators related to blood flow, The identification unit identifies the location of the index acquired by the acquisition means on an image including blood vessels collected by a medical image diagnostic device, A display control unit that displays the acquisition position on the image including the blood vessel, and displays the index on the display unit in correspondence with the acquisition position. A blood pressure monitor characterized by having the following features.

[0102] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]

[0103] 100 X-ray diagnostic equipment 120 Specific section 130 Display Control Unit

Claims

1. An image acquisition unit that acquires multiple contrast-enhanced images, A determination unit determines one of the multiple contrast-enhanced images as the first contrast-enhanced image in response to user operations referring to the multiple contrast-enhanced images, each showing the electrocardiogram waveform at the time of acquisition of the multiple contrast-enhanced images and the heart rate phase at the time of acquisition of the multiple contrast-enhanced images relative to the electrocardiogram waveform; A unit that identifies the measurement position on the fluoroscopic image by a device for measuring blood flow indicators, and identifies the display position on the first contrast-enhanced image corresponding to the identified measurement position, A display control unit that displays an index related to blood flow corresponding to the measurement position at a display position on the first contrast-enhanced image, An image processing device equipped with the following features.

2. The image processing apparatus according to claim 1, wherein the blood flow index is one of FFR (Fractional Flow Reserve), CFR (Coronary Flow Reserve), iFR (instant wave-free ratio), and IMR (Index of Microcirculatory Resistance).

3. The image processing apparatus according to claim 1 or 2, further comprising an input unit for receiving user operations.

4. The image processing apparatus according to any one of claims 1 to 3, wherein the identifying unit identifies a display position on the first contrast image corresponding to the identified measurement position based on the position of the device specified by the user's operation on the first contrast image.

5. A collection unit that collects multiple contrast-enhanced images of the subject under contrast conditions, A determination unit determines one of the multiple contrast-enhanced images as the first contrast-enhanced image in response to user operations referring to the multiple contrast-enhanced images, each showing the electrocardiogram waveform at the time of acquisition of the multiple contrast-enhanced images and the heart rate phase at the time of acquisition of the multiple contrast-enhanced images relative to the electrocardiogram waveform; A unit that identifies the measurement position on the fluoroscopic image by a device for measuring blood flow indicators, and identifies the display position on the first contrast-enhanced image corresponding to the identified measurement position, A display control unit that displays an index related to blood flow corresponding to the measurement position at a display position on the first contrast-enhanced image, An X-ray diagnostic device equipped with [specific features / features].

6. Acquire multiple contrast-enhanced images, In response to user operations referring to multiple contrast-enhanced images, each showing the electrocardiogram waveform at the time of acquisition of the multiple contrast-enhanced images and the heart rate phase at the time of acquisition of the contrast-enhanced images relative to the electrocardiogram waveform, one of the multiple contrast-enhanced images is determined as the first contrast-enhanced image. On the fluoroscopic image, the measurement position of a device for measuring blood flow indicators is identified, and the display position on the first contrast-enhanced image corresponding to the identified measurement position is identified. An index relating to blood flow corresponding to the measurement location is displayed at the display location on the first contrast-enhanced image. An image processing method that includes the following.

Images