Respiratory action display device, method of operating respiratory action display device, and diagnostic imaging system

Abstract

To provide a respiratory action display device, an operation method of the respiratory action display device and an image diagnostic system, allowing a subject to excellently recognize his / her own respiratory action without moving the line of sight.SOLUTION: A respiratory action display system (200) includes a processor (210), a projector (230) configured to display an image in a manner visible to a subject during an examination of the subject by a magnetic resonance imaging (MRI) device (100), and a respiratory sensor including a first camera (220A) and a second camera (220B) configured to detect a respiratory action of the subject, wherein the processor (210) is configured to generate a rotationally symmetric first diagram having a fixed center and changing in size according to a displacement of a respiratory waveform corresponding to the respiratory action detected by the respiratory sensor, and cause the projector (230) to project the generated first diagram as an image.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a breathing movement display device, a method for operating the same, and an image diagnostic system, and more particularly to a technique that allows a subject to clearly recognize his or her own breathing movement. [Background technology]

[0002] Conventionally, respiratory-gated imaging or breath-holding imaging has been used to examine a subject's abdomen using diagnostic imaging devices such as magnetic resonance imaging (MRI) devices and X-ray computed tomography (CT) devices in order to reduce motion artifacts caused by the subject's breathing.

[0003] In respiratory-gated imaging, a respiratory sensor is attached to the subject's abdomen, and data is collected only when abdominal movement is small and stable (mainly during exhalation). The imaging time depends on the subject's respiratory state, and even if the respiratory cycle is stable, degradation of image quality becomes an issue if the depth of breathing is unstable.

[0004] For this reason, a technique has been proposed in which an indicator or the like is displayed to guide the breathing of a subject in the bore of an imaging diagnostic device (Patent Documents 1 and 2).

[0005] One embodiment of the method for providing instructions to a patient described in Patent Document 1 displays a first indicator that moves in a first direction and a second direction (i.e., upward and downward) to match the patient's breathing, and a second indicator consisting of a bar including a first line representing the minimum inhalation level of a prescribed breath and a second line representing the maximum inhalation level of a prescribed breath. When performing breath-hold imaging, the patient adjusts the depth of their breathing and stops breathing so that the first indicator falls within the bar indicated by the second indicator.

[0006] In addition, another embodiment of the method for providing instructions to a patient described in Patent Document 1 displays a curve (moving curve) representing the desired respiratory waveform to be achieved as a target, and the patient adjusts their breathing so that the first indicator follows the curve as closely as possible.

[0007] The MRI apparatus described in Patent Document 2 displays the respiratory state in a manner that can be visually recognized by the subject, and in particular, displays the depth of breathing using a scale or the light-emitting position of a light spot. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Special Publication No. 2008-514371 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-158762 Summary of the Invention [Problem to be solved by the invention]

[0009] The method described in Patent Document 1 requires the patient to adjust the depth of breathing, etc., to match the target second indicator while watching the first indicator, which moves upward and downward in response to the patient's breathing. Because the first indicator moves in response to breathing, there is a high possibility that the patient's line of sight will move, inducing body movements other than breathing. In addition, there is a problem that it is difficult for subjects with poor eyesight to see the first indicator and the second indicator.

[0010] The MRI device described in Patent Document 2 also has the problem that the subject's line of sight moves when checking the scale indicating the depth of breathing or the light spot's light emission position, which increases the possibility of inducing body movements other than breathing.

[0011] The present invention has been made in consideration of the above circumstances, and aims to provide a breathing movement display device, an operating method for a breathing movement display device, and an image diagnostic system that can reduce the movement of the subject's line of sight and enable the subject to clearly recognize his or her own breathing movement. [Means for solving the problem]

[0012] The invention according to a first aspect is a respiratory movement display device comprising a processor, a display that displays an image in a manner that is visible to the subject during examination of the subject by an imaging diagnostic device, and a respiratory sensor that detects the respiratory movement of the subject, wherein the processor generates a rotationally symmetric first figure with a fixed center, whose size changes according to a displacement of a respiratory waveform corresponding to the respiratory movement detected by the respiratory sensor, and causes the generated first figure to be displayed as an image on the display.

[0013] According to the first aspect of the present invention, a subject undergoing an examination using an imaging diagnostic device can check his or her breathing and depth by viewing a rotationally symmetric first figure with a fixed center, the size of which changes in response to the displacement of a respiratory waveform corresponding to the subject's breathing. In particular, since the center (center of symmetry) of the first figure does not move, the subject can fix his or her gaze when viewing the first figure. This makes it possible to suppress the induction of body movements other than breathing.

[0014] In the respiratory action display device according to the second aspect of the present invention, in the first aspect, it is preferable that the maximum and minimum values ​​of the respiratory waveform are detected, the sizes of the first figure when the respiratory waveform reaches the maximum and minimum values ​​are set to the maximum and minimum sizes, and when the respiratory waveform varies between the maximum and minimum values, the first figure is generated whose size varies between the maximum and minimum sizes according to the variation of the respiratory waveform detected by the respiratory sensor. This makes it possible to display the first figure with the maximum and minimum sizes at an appropriate size regardless of the variation of the respiratory waveform (depth of breathing) for each subject, and makes the first figure easy to see even for subjects with poor eyesight.

[0015] In the breathing action display device according to the third aspect of the present invention, in the second aspect, the processor preferably displays on the display a second figure similar in outline to the first figure and of the largest size, with the center of the first figure aligned with the first figure. This second figure of the largest size is displayed as a target when the subject's breathing waveform is at its maximum.

[0016] In the breathing action display device according to the fourth aspect of the present invention, in the third aspect, it is preferable that the processor displays the first and second figures on the display device with at least one of color, line type, and brightness different from each other.

[0017] In the respiratory action display device according to the fifth aspect of the present invention, in the third aspect, the processor preferably causes the display to display a third figure similar in outline to the first figure and having a minimum size, with the center of the first figure aligned with the first figure. This minimum size third figure is displayed as a target for when the subject's respiratory waveform is minimized.

[0018] A breathing action display device according to a sixth aspect of the present invention is the fifth aspect, wherein the processor preferably causes the display device to display the first and third figures with different colors, line types, and brightnesses.

[0019] In the respiratory movement display device according to the seventh aspect of the present invention, in the fifth or sixth aspect, the processor preferably generates a respiratory waveform for respiratory synchronized imaging based on respiratory synchronization parameters set during respiratory synchronized imaging by the imaging diagnostic device and the respiratory cycle of the subject, generates a fourth figure similar in outline to the first figure and whose size changes between the second and third figures according to the respiratory waveform for respiratory synchronized imaging, and displays the fourth figure on the display by aligning the center of the fourth figure with the center of the first figure.

[0020] This fourth figure can guide the subject's breathing cycle, phase, and depth, and the subject can breathe in a manner suitable for respiratory-synchronized imaging by breathing so that the first figure, whose size changes according to the subject's respiratory waveform, matches the fourth figure.

[0021] In the breathing action display device according to an eighth aspect of the present invention, in the seventh aspect, it is preferable that the processor displays the first and fourth figures on the display device by making at least one of the color, line type, and brightness different.

[0022] A respiratory movement display device according to a ninth aspect of the present invention is the seventh or eighth aspect, and preferably, the processor displays a warning on the display when the deviation in the outer shapes of the first and fourth figures exceeds a threshold. If the deviation in the outer shapes of the first and fourth figures exceeds the threshold, the respiratory movement is not suitable for respiratory-gated imaging, and a warning is given to the subject.

[0023] In the breathing action display device according to a tenth aspect of the present invention, in any one of the first to ninth aspects, the processor preferably changes the display form of the first figure while the diagnostic imaging device is imaging the subject, thereby informing the subject that the imaging period is approaching.

[0024] In the breathing action display device according to an eleventh aspect of the present invention, in any one of the first to tenth aspects, the processor preferably displays a mark for gaze fixation at the center of the first figure, thereby further encouraging the subject to fix his / her gaze.

[0025] In the breathing action display device according to the twelfth aspect of the present invention, in any of the seventh to ninth aspects, the processor preferably fixes the fourth figure for the period during which the subject should hold their breath when the imaging diagnostic device images the subject while the subject holds their breath.

[0026] In the breathing action display device according to a thirteenth aspect of the present invention, in any one of the seventh to ninth aspects, it is preferable that the first figure has an outer shape of a circle or a regular polygon.

[0027] A fourteenth aspect of the invention is an image diagnostic system including an image diagnostic device and the breathing movement display device of the thirteenth aspect.

[0028] A fifteenth aspect of the present invention provides the imaging diagnostic system of the fourteenth aspect, wherein the imaging diagnostic device includes a magnetic resonance imaging device or an X-ray CT device.

[0029] In the imaging diagnostic system according to the 16th aspect of the present invention, in the 14th or 15th aspect, it is preferable that the imaging diagnostic device is a device capable of respiratory-gated imaging, and the processor displays at least the first figure on the display when the imaging diagnostic device is performing respiratory-gated imaging.

[0030] A seventeenth aspect of the invention is a method for operating a respiratory movement display device including a processor, a display that displays an image visible to the subject during examination of the subject by an imaging diagnostic device, and a respiratory sensor that detects the subject's respiratory movement, the method including the steps of: acquiring a respiratory waveform corresponding to the respiratory movement detected by the respiratory sensor; generating a rotationally symmetric first figure with a fixed center that changes according to the displacement of the acquired respiratory waveform; and displaying the generated first figure as an image on the display. [Effects of the Invention]

[0031] According to the present invention, a subject undergoing an examination using an imaging diagnostic device can clearly recognize his or her own breathing movement without moving his or her line of sight by viewing a rotationally symmetric first figure with a fixed center, the figure changing in size according to the displacement of the respiratory waveform corresponding to the subject's own breathing movement. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a perspective view showing the appearance of a magnetic resonance imaging apparatus (MRI apparatus) to which the breathing movement display device according to the present invention is applied. [Figure 2] FIG. 2 is a diagram showing a schematic internal configuration of the MRI apparatus shown in FIG. [Figure 3] FIG. 3 is a diagram showing the external configuration of the main part of the breathing action display device according to the present invention. [Figure 4]FIG. 4 is a block diagram showing an embodiment of an image diagnostic system according to the present invention. [Figure 5] FIG. 5 is a diagram showing an example of a respiratory waveform 240 indicating the respiratory movement of the subject. [Figure 6] FIG. 6 is a diagram showing a part of an image (figure) projected by a projector, and in particular an example of a second figure C2 and a third figure C3 corresponding to the maximum and minimum values ​​of the respiratory waveform. [Figure 7] FIG. 7 is a diagram showing a figure projected by a projector, and in particular a figure obtained by combining a first figure C1, a second figure C2, and a third figure C3. [Figure 8] FIG. 8 is a flow chart illustrating an embodiment of a method of operating a breathing movement indicator according to the present invention. [Figure 9] FIG. 9 is a waveform diagram showing an example of a respiratory waveform for respiratory-gated imaging when respiratory-gated imaging is performed by an MRI apparatus. [Figure 10] FIG. 10 is a diagram showing a figure projected by a projector, and in particular a figure obtained by combining a first figure C1, a second figure C2, and a fourth figure C4. [Figure 11] FIG. 11 is a diagram showing a figure projected by a projector, and in particular a diagram showing an example of a figure when the subject's breathing no longer follows breathing for respiratory guidance. [Figure 12] FIG. 12 is a diagram showing a figure projected by a projector, and in particular another example of a figure when the subject's breathing no longer follows breathing for respiratory guidance. [Figure 13] FIG. 13 is a diagram showing a figure projected by a projector, and in particular showing how the display form of the first figure changes depending on whether respiratory-gated measurement is being performed or not. [Figure 14] FIG. 14 is a diagram showing a part of a figure projected by a projector, and in particular a diagram showing a mark for fixing the line of sight. [Figure 15] FIG. 15 is a diagram showing a figure projected by a projector, and in particular a figure obtained by combining a first figure H1 and a second figure H2. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, preferred embodiments of a breathing movement display device, a method for operating the breathing movement display device, and an image diagnostic system according to the present invention will be described with reference to the accompanying drawings.

[0034] FIG. 1 is a perspective view showing the appearance of a magnetic resonance imaging apparatus (MRI apparatus) to which the breathing movement display device according to the present invention is applied.

[0035] The MRI apparatus 100 shown in FIG. 1 includes a gantry 110 and a bed 130 having a top plate 130A arranged in front of a bore 120, which is a cylindrical imaging space provided in the gantry 110.

[0036] [Internal structure of an MRI device] FIG. 2 is a diagram showing a schematic internal configuration of the MRI apparatus shown in FIG.

[0037] As shown in FIG. 2, the MRI apparatus 100 includes a static magnetic field generating magnet 104 that generates a uniform static magnetic field in an imaging space in which a subject 102 is placed, a gradient magnetic field coil (GC: Gradient Coil) 106, an RF (Radio Frequency) coil (transmitting coil) 108, a receiving coil 140, a high frequency magnetic field generator 112, a receiver 114, and a gradient magnetic field power supply 116.

[0038] The gradient magnetic field coil 106 is composed of gradient magnetic field coils in three directions, X, Y, and Z, and generates gradient magnetic field pulses in the imaging space in response to signals from a gradient magnetic field power supply 116. The transmission coil 108 generates a high-frequency magnetic field in response to signals from a high-frequency magnetic field generator 112, which generates nuclear magnetic resonance (NMR) signals in the nuclei of atoms that make up the tissue of the subject 102.

[0039] The receiving coil 140 detects an NMR signal generated from the subject 102. The detected NMR signal is transmitted to the receiver 114 via a signal cable 142. The signal is converted from analog to digital by an AD (analog-to-digital) converter in the receiver 114, and measurement data (raw data) is generated.

[0040] The MRI apparatus 100 further includes a signal processing unit 118, a control unit 150, an operation unit 160, and a display unit 170.

[0041] The signal processing unit 118 performs an inverse Fourier transform on the measurement data generated by the receiver 114 to reconstruct an image, and outputs the reconstructed image signal to the control unit 150 and the display unit 170. Note that, although an example in which the receiving coil 140 is connected to the signal processing unit 118 and the control unit 150 via the signal cable 142 has been described in FIG. 2 , the connection between the receiving coil 140 and the signal processing unit 118 and / or the control unit 150 is not limited to being wired, but may be wireless. As an example of a wireless connection, the receiving coil 140 further includes an AD converter and a wireless communication module, and digital data (e.g., measurement data) generated by the receiving coil 140 is sent wirelessly to the wireless communication module in the signal processing unit 118 and / or the control unit 150.

[0042] The control unit 150 has a measurement control unit and a calculation unit (not shown), and controls the entire device including the high-frequency magnetic field generator 112, the gradient magnetic field power supply 116, and the display unit 170. The display unit 170 displays the reconstructed image and the video of the subject 102 captured by the first camera 220A and the second camera 220B shown in Fig. 3, and also functions as a part of a user interface when the operator inputs various parameters, etc.

[0043] The control unit 150 receives the position and size of the specific area and the examination protocol (imaging plan) by the operator operating the operation unit 160, and sends commands to the high-frequency magnetic field generator 112 and the gradient magnetic field power supply 116 according to the pulse sequence corresponding to the imaging plan, thereby generating a high-frequency magnetic field and a gradient magnetic field, respectively.

[0044] In the abdominal examination protocol, respiratory synchronization measurement or breath-holding measurement is used. When performing respiratory synchronization measurement or breath-holding measurement, a respiratory sensor is attached to the subject 102, and the control unit 150 performs imaging synchronized with the signal from the respiratory sensor.

[0045] Furthermore, the control unit 150 generates a file in a medical image format from the image signal designated by the operation unit 160 among the image signals processed by the signal processing unit 118, and registers it in an image database (not shown) or the like.

[0046] The signal processing unit 118 and the control unit 150 can be realized by a computer having a processor such as a CPU (Central Processing Unit) and a memory for storing control programs and parameters, etc., executing calculation and control programs.

[0047] Fig. 3 is a diagram showing the external configuration of the main parts of the breathing action display device according to the present invention. In Fig. 3, parts that are common to Fig. 1 and Fig. 2 are given the same reference numerals, and detailed description thereof will be omitted.

[0048] 3, a first camera 220A and a second camera 220B are disposed on the gantry 110 to capture an image of the subject 102 in the bore 120. By analyzing the images from the first camera 220A and the second camera 220B, the breathing movement of the subject 102 can be detected. That is, the first camera 220A and the second camera 220B function as part of a breathing sensor that detects the breathing movement of the subject 102.

[0049] Furthermore, the respiratory bands 222A and 222B are attached to the chest and abdomen of the subject 102, respectively, and function as part of a respiratory sensor for detecting changes in the shape of the chest and abdomen (respiratory movement).

[0050] The respiratory sensor may be a non-contact type using a first camera 220A and a second camera 220B, or a contact type using respiratory bands 222A and 222B. The number of cameras and the number of respiratory bands are not limited to those in the embodiment shown in FIG.

[0051] Furthermore, the respiratory sensor may be a sheet with multiple built-in pressure sensors that is placed under the subject. The pressure sensors in the sheet detect pressure signals as the subject 102 breathes, and information about the subject's breathing can be obtained from the pressure signals.

[0052] Furthermore, the respiration sensor may be a sensor in which a motion sensor (HF resonator) is incorporated in the top board 130A of the bed 130, and the respiration information of the subject 102 is acquired from the HF signal of the HF resonator.

[0053] The projector 230 projects an image onto the ceiling inside the bore 120, and functions as a display that displays the image in a manner that can be seen by the subject 102 during the examination of the subject 102.

[0054] [Imaging diagnostic system] FIG. 4 is a block diagram showing an embodiment of an image diagnostic system according to the present invention.

[0055] The image diagnostic system shown in Fig. 4 includes an MRI apparatus 100, which is an image diagnostic apparatus, and a breathing movement display device 200. The configuration of the MRI apparatus 100 is as specifically shown in Figs.

[0056] The breathing operation display device 200 is composed of a processor 210, a first camera 220A, a second camera 220B, and a projector 230.

[0057] The first camera 220A and the second camera 220B are used as part of a respiratory sensor during respiratory synchronization measurement or breath-holding measurement, and therefore may be those provided in the MRI apparatus 100. Also, instead of the first camera 220A and the second camera 220B, respiratory bands 222A and 222B may be used as respiratory sensors.

[0058] The processor 210 is composed of a CPU and the like, and controls each part of the breathing action display device 200 in an integrated manner, and also executes various processes including a process for generating an image to be projected from the projector 230.

[0059] The processor 210 and the control unit 150 of the MRI apparatus 100 are capable of communicating with each other, and when the MRI apparatus 100 performs respiratory synchronization measurement or breath-holding measurement, the processor 210 causes the projector 230 to project an image showing the breathing movement of the subject 102 onto the ceiling in the bore 120. Furthermore, when the MRI apparatus 100 performs imaging of a body part that is not affected by breathing movement, such as the head, the processor 210 causes the projector 230 to project an image for relaxing the subject 102, instead of an image showing breathing movement.

[0060] In addition, when the signal processing unit 118 and the control unit 150 of the MRI apparatus 100 are configured by a computer having a processor and a memory as described above, the processor of the MRI apparatus 100 may function as the processor 210 of the breathing movement display device 200.

[0061] <First embodiment of breathing movement display device> Next, a first embodiment of the breathing action display device according to the present invention will be described.

[0062] When respiratory synchronization measurement or breath-holding measurement is performed by the MRI device 100, the processor 210 of the respiratory movement display device 200 shown in FIG. 4 analyzes the images of the subject 102 captured by the first camera 220A and the second camera 220B, and acquires a respiratory waveform indicating the respiratory movement of the subject 102.

[0063] FIG. 5 is a diagram showing an example of a respiratory waveform 240 indicating the respiratory movement of the subject 102.

[0064] The processor 210 detects the maximum value Amax and minimum value Amin of the respiratory waveform 240. In this case, the maximum value Amax and minimum value Amin can be the average of multiple maximum values ​​and the average of multiple minimum values ​​of multiple cycles of the respiratory waveform 240, respectively. The detection of the maximum value Amax and minimum value Amin of the respiratory waveform 240 is preferably performed before the start of respiratory synchronized measurement or breath-holding measurement, but may also be performed during respiratory synchronized measurement or breath-holding measurement so as to update the maximum value Amax and minimum value Amin.

[0065] FIG. 6 is a diagram showing a part of the image (figure) projected by the projector 230, and in particular an example of a second figure C2 and a third figure C3 corresponding to the maximum and minimum values ​​of the respiratory waveform.

[0066] As shown in Fig. 6, the second and third figures C2 and C3 are two concentric circles, one large and one small. The second and third figures C2 and C3 are large and small circles of predetermined fixed maximum and minimum sizes, regardless of the variation in the respiratory waveform (depth of breathing) for each subject.

[0067] The second and third figures C2 and C3 are parts of the figure projected from projector 230 onto the ceiling inside bore 120. If the size of the projection area projected from projector 230 onto the ceiling inside bore 120 is, for example, 20 cm × 20 cm, the diameter of second figure C2 can be approximately 15 cm. This allows even a subject with poor eyesight who cannot wear glasses inside MRI apparatus 100 to clearly see second figure C2 and third figure C3.

[0068] Next, the processor 210 acquires a respiratory waveform (respiratory waveform signal) 240 corresponding to the breathing of the subject 102 by analyzing the images from the first camera 220A and the second camera 220B.

[0069] The processor 210 generates a first figure C1 whose size changes according to the displacement of the respiratory waveform 240 based on the displacement (height) of the respiratory waveform 240 acquired sequentially, the maximum value Amax and minimum value Amin of the respiratory waveform 240 (see Figure 5), and the maximum and minimum sizes of the second figure C2 and the third figure C3.

[0070] FIG. 7 is a diagram showing a figure projected by the projector 230, and in particular a figure obtained by combining a first figure C1, a second figure C2, and a third figure C3.

[0071] The first figure C1 is a figure similar in outline to the second and third figures C2 and C3, and is a figure to be combined with the second and third figures C2 and C3 so as to coincide with the centers of the second and third figures C2 and C3. That is, the first figure C1 has the outline of concentric circles that coincide with the centers of the second and third figures C2 and C3.

[0072] Furthermore, it is preferable that the first graphic C1 differs from the second graphic C2 and the third graphic C3 in at least one of color, line type, and brightness. The first graphic C1 shown in Fig. 7 is filled in with a color and / or brightness different from the second graphic C2 and the third graphic C3.

[0073] The first diagram C1 on the left side of FIG. 7 shows the case of exhalation where the respiratory waveform has a minimum value, and the first diagram C1 on the right side of FIG. 7 shows the case of inhalation where the respiratory waveform has a maximum value.

[0074] The size (size of the circle) of the first figure C1 changes according to the displacement of the respiratory waveform corresponding to the breathing of the subject. When the displacement of the respiratory waveform increases and matches the maximum value Amax of the pre-measured respiratory waveform 240, the first figure C1 expands to match the outer shape of the second figure C2, and when the displacement of the respiratory waveform decreases and matches the minimum value Amin of the pre-measured respiratory waveform 240, the first figure C1 shrinks to match the outer shape of the third figure C3.

[0075] In FIG. 7, the outline of the first figure C1 in the case of exhalation is the same as the outline of the smallest size third figure C3, while the outline of the first figure C1 in the case of inhalation is slightly smaller than the largest size second figure C2.

[0076] This is because the displacement of the respiratory waveform during exhalation coincides with the minimum value Amin of the respiratory waveform 240, whereas the displacement of the respiratory waveform during inhalation is slightly smaller than the maximum value Amax of the respiratory waveform 240.

[0077] Furthermore, if the displacement of the respiratory waveform 240 in the case of exhalation is smaller than the minimum value Amin of the respiratory waveform 240, the outline of the first figure C1 will be smaller than the outline of the third figure C3, and if the displacement of the respiratory waveform 240 in the case of inhalation is larger than the maximum value Amax of the respiratory waveform 240, the outline of the first figure C1 will be larger than the outline of the second figure C2.

[0078] In addition, in Figure 7, the third figure C3, which is the smallest size and serves as the target for exhalation, overlaps with the first figure C1 so that it cannot be seen, but if, for example, the first figure C1 and the third figure C3 overlap, it is preferable to set the transparency when combining the first figure C1 so that the third figure C3 in the background can also be seen, or to combine the third figure C3 on top of the first figure C1.

[0079] [Method of operating the breathing movement display device] FIG. 8 is a flowchart showing an embodiment of the operating method of the respiratory movement display device according to the present invention, and shows the processing contents and procedures by the processor 210 of the respiratory movement display device 200 of the first embodiment when the MRI apparatus 100 performs, for example, respiratory synchronized imaging.

[0080] In FIG. 8, the processor 210 analyzes the images from the first camera 220A and the second camera 220B functioning as breathing sensors, and acquires the displacement of the breathing waveform 240 (breathing waveform signal) corresponding to the breathing movement of the subject 102 (step S10).

[0081] The processor 210 temporarily holds the displacement of the respiratory waveform 240 acquired in step S10 for a period corresponding to multiple cycles of the respiratory waveform 240, detects a representative value (e.g., average value) of multiple maximum values ​​in the held multiple cycles of the respiratory waveform 240 as the maximum value Amax of the respiratory waveform 240 of the subject 102, and similarly detects a representative value of multiple minimum values ​​in the multiple cycles of the respiratory waveform 240 as the minimum value Amin of the respiratory waveform of the subject 102 (step S20, see FIG. 5). The maximum value Amax and minimum value Amin of the respiratory waveform 240 of the subject 102 are determined before respiratory-gated imaging by the MRI apparatus 100 is started, but the maximum value Amax and minimum value Amin may also be detected and updated during respiratory-gated imaging.

[0082] Next, the processor 210 generates a first figure C1 whose size changes according to the displacement (height) of the current respiratory waveform 240 acquired in step S10, based on the maximum value Amax and minimum value Amin of the respiratory waveform 240 of the subject 102 detected in step S20, and the size of the second figure C2 and the size of the third figure C3 (step S40).

[0083] That is, for example, when the displacement of the respiratory waveform 240 of the subject 102 changes between the maximum value Amax and the minimum value Amin detected in step S30, the processor 210 generates a first figure C1 whose size (in this example, diameter) changes between the size of the second figure C2 and the size of the third figure C3 in accordance with the displacement of the respiratory waveform 240.

[0084] Furthermore, since the displacement of the respiratory waveform 240 of the subject 102 does not change exactly between the maximum value Amax and the minimum value Amin (there is an error), the size of the first figure C1 at its maximum and minimum will deviate from the second figure C2 and the third figure C3 by the amount of that error.

[0085] Furthermore, in this example, the second figure C2 and the third figure C3 are circles of two known sizes, one large and one small, so the size of the second figure C2 and the size of the third figure C3 can be, for example, the diameters of the two circles, one large and one small, and can be obtained from a memory built into the processor 210, etc.

[0086] The processor 210 generates a composite image from the first figure C1 generated in step S40 and the known second figure C2 and third figure C3 so that their centers coincide, and sends the generated image to the projector 230, which projects (displays) it onto the ceiling of the bore 120 (step S40).

[0087] Here, the second figure C2 and the third figure C3 are each known figures, and can be vector data or a bitmap corresponding to an image projected onto the ceiling of the bore 120 in the gantry 110 of the MRI device 100 by the projector 230, and can be obtained from a memory built into the processor 210, etc.

[0088] Next, the processor 210 determines whether or not the respiratory-gated imaging by the MRI apparatus 100 has ended (step S50). If the processor 210 determines that the respiratory-gated imaging has not ended (in the case of "No"), it returns to step S10 and repeats the processes of steps S10 to S50. If the processor 210 determines that the respiratory-gated imaging has ended (in the case of "Yes"), it ends the operation of the respiratory movement display device 200. The processor 210 can determine whether or not the respiratory-gated imaging has ended based on communication with the control unit 150 of the MRI apparatus 100.

[0089] According to the first embodiment, the subject 102 can check the status of the displacement of the respiratory waveform corresponding to his / her own breathing by viewing the image of the first figure C1 or the like projected on the ceiling of the bore 120. In particular, by viewing the first figure or the like, whose center is fixed even if the size changes according to the displacement of the respiratory waveform, the subject 102 can suppress the induction of body movements other than breathing without moving his / her line of sight. Furthermore, the subject 102 can suppress variations in the depth of breathing by comparing the first figure C1, which has the same center, with the second figure C2 corresponding to the maximum value of the respiratory waveform and the third figure C3 corresponding to the minimum value of the respiratory waveform.

[0090] <Second embodiment of breathing movement display device> Next, a second embodiment of the breathing action display device according to the present invention will be described.

[0091] FIG. 9 is a waveform diagram showing an example of a respiratory waveform for respiratory-gated imaging when the MRI apparatus 100 performs respiratory-gated imaging.

[0092] A respiratory waveform 242 shown in FIG. 9 is an ideal respiratory waveform suitable for respiratory-gated imaging, which is set in correspondence with a respiratory waveform including the respiratory cycle of the subject, for example.

[0093] The processor 210 can generate a respiratory waveform 242 for respiratory gated imaging based on respiratory gated parameters set during respiratory gated imaging and the respiratory cycle of the subject.

[0094] The respiratory gating parameters include, for example, the trigger point TP and the trigger window TW shown in FIG.

[0095] Now, in the respiratory waveform 242 shown in Figure 9, if the respiratory cycle is 100%, the trigger point TP is the point at which measurement starts from the first peak of the respiratory waveform 242, and the trigger window TW is the period from the end of measurement to the trigger point TP of the next peak.

[0096] 9, the trigger point TP is 20% from the first peak of the respiratory waveform 242, and the trigger window TW is 40% of the period from the end of measurement to the trigger point TP of the next peak. When the trigger window TW is 40%, the acquisition window AW other than the trigger window TW is 60%, and measurement (imaging) is performed within this acquisition window AW.

[0097] The respiratory synchronization parameters may be set by the operator on the operation unit 160 based on experience after checking the respiratory waveform of the subject 102, or may be set automatically by the control unit 150 of the MRI apparatus 100 based on the respiratory waveform of the subject 102.

[0098] In the second embodiment of the respiratory motion display device, the processor 210 generates a respiratory waveform 242 for respiratory gated imaging based on respiratory gated parameters set during respiratory gated imaging and the respiratory cycle of the subject 102.

[0099] Next, the processor 210 generates a fourth figure C4 for respiratory induction, which has a similar outline to the first figure C1 (second figure C2, third figure C3) and whose size changes between the second figure and the third figure according to the respiratory waveform 242 for respiratory-synchronized imaging.

[0100] FIG. 10 is a diagram showing a figure projected by the projector 230, and in particular a figure obtained by combining a first figure C1, a second figure C2, and a fourth figure C4.

[0101] The processor 210 generates a fourth graphic C4 for respiratory guidance, which has a display form that can be distinguished from the first graphic C1, etc. In the example shown in Fig. 10, the fourth graphic C4 is displayed as a dotted circle.

[0102] The processor 210 can make the first and fourth figures C1 and C4 distinguishable by making at least one of the color, line type, and brightness different between the first and fourth figures C1 and C4. Although the first and fourth figures C1 and C4 do not overlap in Fig. 10, it is preferable to set the transparency when compositing the first figure C1 so that the fourth figure C4 is always visible regardless of the size of the first figure C1, so that the fourth figure C4 behind the first figure C1 can be visible when they overlap, or to composite the fourth figure C4 on top of the first figure C1.

[0103] The processor 210 generates an image by combining the generated fourth figure C4 for respiratory guidance with the first figure C1, etc. so that it coincides with the center of the first figure C1, etc., and sends the generated image to the projector 230, which projects (displays) it onto the ceiling of the bore 120.

[0104] The fourth graphic C4 for respiratory guidance changes in size between the second graphic C2 and the third graphic C3 in accordance with the respiratory waveform 242 for respiratory-gated imaging shown in Fig. 9. That is, the fourth graphic C4 changes in size in accordance with the displacement of the respiratory waveform 242 for respiratory-gated imaging, and has the function of guiding the subject 102 in terms of the respiratory cycle, phase, and depth.

[0105] In the exhalation state shown in Figure 10, the outline of the first figure C1 is smaller than the outline of the respiratory waveform 242, and as a result, the subject 102 can recognize that the phase and depth of the current respiratory waveform of the subject 102 are shifted from the respiratory waveform 242 for respiratory-synchronized imaging.

[0106] Furthermore, in the inhalation state shown in FIG. 10, the outline of the first figure C1 matches the outline of the fourth figure C4 for respiratory guidance, and as a result, the subject 102 can recognize that the subject's current breathing (respiratory phase, depth) matches the breathing for respiratory-synchronized imaging.

[0107] According to the second embodiment, the fourth graphic C4 for respiratory guidance, which changes in size according to the displacement of the respiratory waveform 242 for respiratory-gated imaging, is displayed, so that the subject 102 can breathe in a manner suitable for respiratory-gated imaging by breathing so that the first graphic C1, which changes according to the displacement of the subject's own respiratory waveform, coincides with the fourth graphic C4 for respiratory guidance. This makes it possible to reduce motion artifacts caused by the breathing of the subject 102 when respiratory-gated imaging is performed using the MRI apparatus 100.

[0108] In addition, when the subject 102 holds his / her breath and the MRI device 100 images the subject 102 (when performing breath-hold measurement), the processor 210 fixes the fourth figure C4 for respiratory guidance during the period when the subject 102 should hold his / her breath.

[0109] Furthermore, when the fourth graphic C4 is fixed, it is preferable to further change the display form of at least one of the first graphic C1 to the fourth graphic C4 to alert the subject 102 that it is a period in which breathing should be held. For example, when the fourth graphic C4 is brightened during the data collection period as described below, it is possible to further brighten the brightness during the period in which breathing should be held, giving priority over the data collection period, to alert the subject 102.

[0110] In addition, when multiple breath-holding measurements are performed, it is preferable that the processor 210 displays the fourth graphic C4 for respiratory guidance corresponding to normal breathing during the period between one breath-holding measurement and the next breath-holding measurement.

[0111] <Modification of the second embodiment of the breathing movement display device> FIG. 11 is a diagram showing a figure projected by the projector 230, and in particular a diagram showing an example of a figure when the breathing of the subject 102 no longer follows the breathing for respiratory guidance.

[0112] 11 shows a case where the fourth figure C4, which is the target of the breathing of the subject 102 during respiratory-gated imaging, is getting smaller (changing from inhalation to exhalation), while the first figure C1 is getting larger (the subject 102 is breathing in further). That is, the respiratory waveform of the subject 102 is significantly out of phase with respect to the respiratory waveform 242 for respiratory-gated imaging.

[0113] When the deviation in the outer shape and phase between the first graphic C1 and the fourth graphic C4 exceeds a threshold, the processor 210 causes the projector 230 to display a warning on the ceiling of the bore 120. In the example shown in Fig. 11, the warning is given by displaying a fifth graphic C5 in which the display color (for example, achromatic color) of the fourth graphic C4 is changed to red.

[0114] FIG. 12 is a diagram showing a figure projected by the projector 230, and in particular another example of a figure when the breathing of the subject 102 no longer follows the breathing for respiratory guidance.

[0115] 12 shows a case in which the fourth figure C4, which is the target of the subject's breathing during respiratory-gated imaging, is small, and the first figure C1 is also small, but the first figure C1 is smaller than the fourth figure C4 by more than a threshold value. That is, the displacement of the respiratory waveform of the subject 102 is lower than the target minimum value of the respiratory waveform, and as a result, the outline of the first figure C1 is smaller than the minimum-sized third figure C3 shown in FIG.

[0116] When the outer shape of the first graphic C1 becomes smaller than a threshold value (a target minimum value in the example shown in FIG. 12), the processor 210 causes the projector 230 to display a warning on the ceiling of the bore 120. In the example shown in FIG. 12, the warning is given by displaying a fifth graphic C5 in which the display color (for example, achromatic color) of the fourth graphic C4 is changed to red.

[0117] According to a modified example of the second embodiment, when the breathing (respiratory waveform) of the subject 102 exceeds a threshold and no longer follows the breathing for respiratory induction (respiratory waveform 242), a warning is issued, so that the subject 102 can be prompted to synchronize his / her breathing with the breathing for respiratory induction.

[0118] The warning display is not limited to changing the display form of the fourth graphic C4, and may be performed by displaying characters, a warning mark, or the like.

[0119] <Third embodiment of breathing movement display device> FIG. 13 is a diagram showing a figure projected by the projector 230, and particularly shows a case where the display form of the first figure is changed depending on whether respiratory synchronization measurement is in progress or not.

[0120] When respiratory-gated imaging is performed by the MRI apparatus 100, the processor 210 of the third embodiment of the breathing movement display device changes the first graphic C1 to a first graphic C1' during the period when the MRI apparatus 100 is imaging the subject 102. The processor 210 can change the first graphic C1 to a first graphic C1' by changing at least one of the color and brightness of the first graphic C1, for example.

[0121] As shown in FIG. 9, the first graphic C1 is displayed during the trigger window TW in which breathing is performed, and the first graphic C1' is displayed during the acquisition window AW in which data measurement is performed.

[0122] In the third embodiment, while the MRI apparatus 100 is imaging the subject 102, the first figure C1 is changed to the first figure C1' as shown in FIG. 13, but this is not limiting and the display form may be changed as follows.

[0123] (1) The display form of the fourth graphic C4 for respiratory guidance is changed (for example, at least one of the color and brightness of the fourth graphic C4 is changed).

[0124] (2) The first figure C1 is changed to the first figure C1', and the display form of the fourth figure C4 is also changed.

[0125] (3) The brightness of the entire displayed figure is changed. For example, the figure is displayed brighter during data acquisition periods than during non-data acquisition periods to alert the subject 102. By changing the display brightness, unnecessary text is not displayed, which can reduce the movement of the subject 102's line of sight.

[0126] (4) A few seconds before the start of the data acquisition period, the brightness is gradually changed (faded in) to the brightness of the data acquisition period. This allows the subject 102 to be notified in advance that data acquisition is about to begin.

[0127] Furthermore, in an embodiment where a monitor is provided within the bore 120 instead of the projector 230, the display brightness on the monitor can be changed to notify the subject 102 of the data acquisition period.

[0128] In the example shown in Figure 13, the first figure C1 changes to the first figure C1' from the end of expiration, but in the case of an up trigger, the first figure C1 changes to the first figure C1' from the end of inspiration, resulting in a display form opposite to that shown in Figure 13.

[0129] According to the third embodiment, the subject 102 can be notified that an imaging period has begun, and the subject 102 can suppress breathing during the imaging period.

[0130] <Fourth embodiment of breathing movement display device> FIG. 14 is a diagram showing a part of a figure projected by the projector 230, particularly showing a case where a mark for fixing the line of sight is displayed.

[0131] The processor 210 of the fourth embodiment of the breathing action display device displays a mark M for fixing the gaze at the center of the first graphic C1 (the center of the second graphic C2) shown in Fig. 7 etc. The mark M in this example is a cross mark, but is not limited to this.

[0132] Although the first figure C1 shown in Figure 7 etc. is also displayed, the first figure C1 is omitted in Figure 14. Even when the first figure C1 is displayed, it is preferable to composite the mark M onto the first figure C1 so that it is always visible.

[0133] According to the fourth embodiment, it is possible to further encourage the subject 102 to fix his / her gaze when visually recognizing the first figure C1 etc., and to prevent gaze movement that induces body movement including head movement.

[0134] [others] In this embodiment, the figure including the first figure C1 has a circular outer shape, but this is not limited to this and the figure may be a rotationally symmetric figure with a fixed center, for example, a regular polygon.

[0135] FIG. 15 is a diagram showing a figure projected by the projector 230, and in particular a figure obtained by combining a first figure H1 and a second figure H2.

[0136] The outer shape of the first figure H1 shown in FIG. 15 is a regular hexagon, and similarly the second figure H2 is also a regular hexagon, with the centers of the first figure H1 and the second figure H2 coinciding.

[0137] The first figure H1 corresponds to the first figure C1 shown in Figure 7, and the first figure H1 on the left side of Figure 15 shows the case of exhalation when the respiratory waveform is at its minimum value, and the first figure H1 on the right side of Figure 15 shows the case of inhalation when the respiratory waveform is at its maximum value.

[0138] The size (size of the regular hexagon) of the first figure H1 changes according to the displacement of the respiratory waveform corresponding to the breathing of the subject. When the displacement of the respiratory waveform increases and matches the maximum value Amax of the respiratory waveform measured in advance, the first figure H1 expands to match the outline of the second figure H2. On the other hand, when the displacement of the respiratory waveform decreases and matches the minimum value Amin of the respiratory waveform measured in advance, the first figure H1 shrinks to the size shown on the left side of Fig. 15.

[0139] In addition, in this embodiment, the display that displays the first figure, etc. is a projector 230 that projects an image onto the ceiling of the bore 120 in the gantry 110 of the MRI device 100, but it is not limited to this and may be, for example, a head-up display, a head-mounted display, a monitor such as an LCD display or an organic EL display inside the bore 120, a monitor outside the bore 120, and a set of a mirror for viewing the monitor.

[0140] Furthermore, the diagnostic imaging device to which the breathing movement display device is applied is not limited to an MRI device, but may also be, for example, an X-ray CT device.

[0141] Furthermore, in this embodiment, each process is executed by any computer. Also, any computer may execute these processes by a processor, a program, or a combination thereof. Any computer may be a system such as a general-purpose computer, a specific-purpose computer, a workstation, or other hardware element capable of executing a program.

[0142] The processor may be composed of one or more pieces of hardware, and the type of hardware is not limited. For example, the processor may be composed of hardware such as a programmable logic device such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or an FPGA (Field Programmable Gate Array), a dedicated circuit for executing specific processes such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). The processor also has various units or means for executing various processes in the present embodiment. The type of hardware may also be a combination of different types of hardware. When multiple pieces of hardware are configured to execute one or more processes of a certain processor, the multiple pieces of hardware may exist in devices physically separated from each other or in the same device. In any of the embodiments, the order of the processes performed by the processor is not limited to the order described above and may be changed as appropriate. The hardware may be composed of an electric circuit or the like, which is a combination of circuit elements such as semiconductor devices.

[0143] Furthermore, the present embodiment may be implemented by hardware, software, firmware, microcode, or a combination thereof. Software, firmware, and microcode may be configured by a program. A program may also be, for example, a group of program modules, each function of which may be implemented by a processor configured to perform the respective function. The program may be program code or multiple code segments stored in one or more non-transitory computer-readable media (e.g., storage media or other storages). The program may be stored in multiple non-transitory computer-readable media that reside in physically separate devices. A program code or a code segment may represent a procedure, a function, a subprogram, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A program code or a code segment may be connected to another code segment or a hardware circuit by sending or receiving information, data, arguments, parameters, or memory contents.

[0144] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0145] 100...MRI device 102...Subject 104...Static magnetic field generating magnet 106...Gradient magnetic field coil 108...Transmitting coil 110...Gantry 112...High frequency magnetic field generator 114...Receiver 116...Gradient magnetic field power supply 118...Signal processing unit 120…bore 130...Bed 130A...top plate 140...receiving coil 142...Signal cable 150...Control unit 160...Operation unit 170...Indicator 200...Respiration movement display device 210...processor 220A...1st camera 220B...Second camera 222A, 222B...Breathing band 230...Projector 240, 242...Respiration waveform AW...Acquisition window Amax: Maximum value Amin: Minimum value C1, C1', H1...First shape C2, H2...Second figure C3...Third figure C4...4th figure C5...5th figure M...Mark S10~S50...Step TP...Trigger point TW...Trigger window

Claims

1. A respiratory behavior display device including a processor, a display device that displays an image in a manner that can be seen by a subject during an examination of the subject using an image diagnostic device, and a respiratory sensor that detects the respiratory behavior of the subject, The processor: generating a rotationally symmetric first figure with a fixed center, the size of which changes in accordance with a displacement of a respiratory waveform corresponding to the respiratory movement detected by the respiratory sensor; displaying the generated first figure as the image on the display device; Breathing movement display device.

2. The processor: Detecting maximum and minimum values ​​of the respiratory waveform; the sizes of the first figure when the respiratory waveform reaches the maximum value and the minimum value are set to a maximum size and a minimum size, respectively, and when the respiratory waveform changes between the maximum value and the minimum value, the first figure is generated whose size changes between the maximum size and the minimum size according to the change in the respiratory waveform detected by the respiratory sensor. The breathing movement display device of claim 1 .

3. the processor causes the display device to display a second graphic having a similar outline to the first graphic and having the maximum size, with the center of the second graphic aligned with the center of the first graphic. The breathing movement display device of claim 2 .

4. the processor causes the display device to display the first graphic and the second graphic with at least one of a color, a line type, and a brightness different from each other; The breathing movement display device of claim 3 .

5. The processor: a third figure having a similar external shape to the first figure, the third figure being of the smallest size, is displayed on the display device so as to be centered on the first figure; The breathing movement display device of claim 3 .

6. the processor causes the display device to display the first graphic and the third graphic with at least one of a color, a line type, and a brightness different from each other; The breathing movement display device of claim 5 .

7. The processor: generating a respiratory waveform for respiratory-gated imaging based on respiratory gating parameters set during respiratory-gated imaging by the diagnostic imaging apparatus and a respiratory cycle of the subject; generating a fourth figure having an outline similar to that of the first figure, the fourth figure varying in size between the second figure and the third figure in accordance with the respiratory waveform for respiratory-gated imaging; Displaying the fourth figure on the display device so that the center of the fourth figure coincides with the center of the first figure. The breathing movement display device of claim 5 .

8. the processor causes the display device to display the first graphic and the fourth graphic with at least one of a color, a line type, and a brightness different from each other; The breathing movement display device of claim 7 .

9. the processor causes the display device to display a warning when a deviation in the outer shape between the first figure and the fourth figure exceeds a threshold value.

9. The breathing activity indicator of claim 8.

10. the processor changes the display form of the first figure while the diagnostic imaging apparatus is imaging the subject. The breathing movement display device of claim 1 .

11. the processor displays a mark for gaze fixation at the center of the first figure; The breathing movement display device of claim 1 .

12. When the subject holds his / her breath and the diagnostic imaging apparatus captures an image of the subject, the processor fixes the fourth figure for a period during which the subject should hold his / her breath. The breathing movement display device of claim 7 .

13. The first figure has an outer shape of a circle or a regular polygon. The breathing movement display device according to any one of claims 1 to 12.

14. the diagnostic imaging device; a breathing movement display device according to claim 13; An imaging diagnostic system equipped with

15. The imaging diagnostic device includes a magnetic resonance imaging device or an X-ray CT device. The imaging diagnostic system according to claim 14.

16. the diagnostic imaging device is capable of respiratory-gated imaging, the processor causes the display device to display at least the first graphic during respiratory-gated imaging by the diagnostic imaging apparatus. The imaging diagnostic system according to claim 14.

17. 1. A method for operating a respiratory movement display device including: a processor; a display device that displays an image in a manner that is visible to a subject during an examination of the subject using an imaging diagnostic device; and a respiratory sensor that detects the respiratory movement of the subject, the processor acquiring a respiratory waveform corresponding to the respiratory movement detected by the respiratory sensor; The processor generates a rotationally symmetric first figure having a fixed center, the first figure varying in size according to the displacement of the acquired respiratory waveform; a step of causing the processor to display the generated first figure as the image on the display device; 10. A method of operating a breathing movement indicator, comprising:

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