JP6668085B2 - Medical image diagnostic apparatus and medical image processing apparatus - Google Patents

Description

  An embodiment of the present invention relates to a medical image diagnostic device and a medical image processing device.

  2. Description of the Related Art In the field of medical image diagnostic apparatuses, an apparatus that integrates a device that captures a morphological image of a subject and a device that captures a functional image of the subject has been put to practical use. Examples of an apparatus that captures a morphological image of a subject include an X-ray CT (Computed Tomography) apparatus and a magnetic resonance imaging (MRI) apparatus. An apparatus that captures a functional image of a subject is, for example, a nuclear medicine imaging apparatus. The nuclear medicine imaging apparatus is, for example, a PET (Positron Emission Tomography) apparatus or a SPECT (Single Photon Emission Computed Tomography) apparatus.

  However, a nuclear medicine imaging apparatus may require a long time to capture a functional image. For this reason, the functional image may be affected by the movement of the target part. At present, for example, a PET image captured for each phase of a biological signal is deformed in accordance with a CT image captured while the subject holds his / her breath, and a PET image captured for each phase of the biological signal is deformed. A PET-CT device that corrects motion is known.

  However, the pixels of the morphological image and the pixels of the functional image represent different physical quantities. For this reason, the accuracy of alignment between the morphological image and the functional image may be insufficient.

JP 2009-156856 A

  An object of the present invention is to provide a medical image diagnostic apparatus and a medical image processing apparatus that can generate a functional image in which the influence of the movement of a target part is reduced.

  A medical image diagnostic apparatus according to an embodiment includes a morphological image data collection unit, a displacement calculation unit, a functional image data collection unit, a correction unit, and an adjustment unit. The morphological image data collecting unit collects morphological image data of the target portion in each time phase. The displacement calculating unit calculates a displacement of a morphological image region included in the morphological image data based on the plurality of morphological image data. The functional image data collection unit collects functional image data of the target site in each time phase based on radiation generated by a radiopharmaceutical present in the target site. The correction unit corrects the influence of the movement of the target portion on the functional image data based on the displacement. The adjusting unit is configured to collect a morphological image data period that contributes to the generation of the morphological image data used by the displacement calculation unit to calculate the displacement, and a function that contributes to the generation of the functional image data corrected by the correction unit. Match the image data collection period.

FIG. 1 is a diagram illustrating a medical image diagnostic apparatus according to the first embodiment. FIG. 2 is a diagram illustrating a configuration example of the medical image diagnostic apparatus according to the first embodiment. FIG. 3 is a flowchart illustrating an example of a process performed by the medical image diagnostic apparatus according to the first embodiment. FIG. 4 is a diagram for explaining the relationship between the collection period of the morphological image data, the collection period of the functional image data, and the signal acquired by the signal acquisition circuit according to the first embodiment. FIG. 5 is a diagram illustrating an example of a process performed by the medical image diagnostic apparatus according to the first embodiment. FIG. 6 is a diagram for explaining the relationship between the acquisition period of the morphological image data, the acquisition period of the functional image data, and the signal acquired by the signal acquisition circuit according to the second embodiment. FIG. 7 illustrates a case where the R wave of the electrocardiographic signal of the subject is generated at regular intervals, the acquisition period of the morphological image data, the acquisition period of the functional image data, and the signal acquisition circuit according to the third embodiment. FIG. 4 is a diagram for explaining a relationship between acquired signals. FIG. 8 shows a case where the acquisition period of the morphological image data, the acquisition period of the functional image data, and the signal acquisition circuit according to the third embodiment when the R wave of the electrocardiographic signal of the subject does not occur at regular intervals. FIG. 4 is a diagram for explaining a relationship between acquired signals. FIG. 9 is a diagram for explaining the relationship between the collection period of the morphological image data, the collection period of the functional image data, and the signal acquired by the signal acquisition circuit according to the fourth embodiment. FIG. 10 is a diagram for explaining the relationship between the collection period of morphological image data, the collection period of functional image data, and signals acquired by the signal acquisition circuit according to the fifth embodiment. FIG. 11 is a diagram illustrating an example of a process performed by the medical image diagnostic apparatus according to the fifth embodiment. FIG. 12 is a view for explaining an example of processing performed by the medical image diagnostic apparatus according to any one of the first to fifth embodiments in place of the processing of steps S8 and S9 in FIG. It is.

  Hereinafter, a medical image diagnostic apparatus and a medical image processing apparatus according to an embodiment will be described with reference to the drawings. In the following embodiments, overlapping descriptions will be omitted as appropriate.

(First embodiment)
First, a medical image diagnostic apparatus 1 according to a first embodiment will be described with reference to FIGS. FIG. 1 is a diagram illustrating a medical image diagnostic apparatus according to the first embodiment. FIG. 2 is a diagram illustrating a configuration example of the medical image diagnostic apparatus according to the first embodiment.

  The medical image diagnostic apparatus 1 includes a bed 2, a morphological image data photographing apparatus 3, a functional image data photographing apparatus 4, and a console 5, as shown in FIGS. In the first embodiment, a case where the morphological image data imaging device 3 is an X-ray CT device and the functional image data imaging device 4 is a PET device will be described as an example. In the first embodiment, the morphological image data capturing device 3 and the functional image data capturing device 4 perform electrocardiographic synchronous imaging of the subject's heart, which is the target site.

  The couch 2 includes, as shown in FIG. 2, a table 21, a drive circuit 22, and a signal acquisition circuit 23. The top 21 is a plate-shaped member on which the subject P is placed. The drive circuit 22 is provided, for example, below the top board 21. The drive circuit 22 moves the top plate 21 in the Z direction under the control of the imaging control function 551 of the processing circuit 55 to be described later, thereby moving the subject P to the morphological image data imaging device 3 or the functional image data imaging device 4. To the inside of the shooting opening. Here, the Z direction is the body axis direction of the subject P. 1 and 2, a direction orthogonal to the Z direction in the coronal plane of the subject P is defined as an X direction. 1 and 2, a direction perpendicular to the Z direction in the sagittal plane of the subject P is defined as a Y direction. The X, Y, and Z directions form a right-handed system. The drive circuit 22 is realized by, for example, a processor.

  The signal acquisition circuit 23 acquires a signal from the subject P. This signal is, for example, an electrocardiographic signal of the subject P. In this case, the signal acquisition circuit 23 is included in the electrocardiograph. The electrocardiographic signal is a signal representing a temporal change of a voltage generated by a heartbeat. In the electrocardiographic signal, a waveform called an R wave whose voltage is temporarily increased appears. One R wave to the next R wave correspond to one beat. Further, the signal acquisition circuit 23 stores the acquired electrocardiogram signal in the data storage circuit 53 described later. Note that the signal acquisition circuit 23 is realized by, for example, a processor.

  As shown in FIG. 2, the morphological image data photographing apparatus 3 includes an X-ray tube 31, an X-ray detector 32, a rotating frame 33, and a data collection circuit 34.

  The X-ray tube 31 generates X-rays for irradiating the subject P. The X-ray tube 31 has a wedge and a collimator. The wedge is a filter for adjusting the dose of X-rays applied to the subject P. The collimator is a slit for narrowing the irradiation range of the X-ray whose dose is adjusted by the wedge.

  The X-ray detector 32 has a plurality of detection elements arranged in a channel direction and a slice direction. The detection element detects the intensity of the incident X-ray. The channel direction is the circumferential direction of the rotating frame 33. The slice direction is the Z direction. The X-ray detector 32 has, for example, as many detection elements as necessary to collect volume data of the entire heart of the subject P in one conventional scan in the channel direction and the slice direction.

  The detection element has a scintillator, a photodiode, and a detection circuit. First, the detection element converts incident X-rays into light using a scintillator. Next, the detection element converts the light into electric charge by the photodiode. Then, the detection element converts the electric charge into an electric signal by the detection circuit and outputs the electric signal to a data collection circuit 34 described later.

  The rotating frame 33 is an annular frame. The rotating frame 33 supports the X-ray tube 31 and the X-ray detector 32 so as to face each other with the subject P interposed therebetween. The rotating frame 33 is driven by an imaging control function 551 of a processing circuit 55 described later, and rotates at high speed on a circular orbit around the subject P.

  The data collection circuit 34 generates morphological image data based on the electric signal output from the detection element. The morphological image data is projection data for generating a morphological image. This projection data is, for example, a sinogram. The sinogram is data in which signals detected by each detection element at each position of the X-ray tube 31 are arranged. Here, the position of the X-ray tube 31 is called a view. The sinogram is data in which the intensity of the X-ray detected by the detection element is assigned to a two-dimensional orthogonal coordinate system in which a first direction is a view direction and a second direction orthogonal to the first direction is a channel direction. The data collection circuit 34 stores the generated sinogram in a data storage circuit 53 described later. The data collection circuit 34 is included in a DAS (Data Acquisition System). The data collection circuit 34 is realized by, for example, a processor.

  The functional image data photographing device 4 includes a γ-ray detector 41 and a coincidence counting information collecting circuit 42 as shown in FIG.

  The γ-ray detector 41 has a plurality of detector modules 411. The detector module 411 is an indirect conversion type detector including a scintillator, a light guide, and a photomultiplier tube (PMT).

  The scintillator converts a pair of γ-rays emitted in substantially opposite directions due to the positrons contained in the radiopharmaceutical administered to the subject P annihilating with the electrons in the subject P into visible light. A plurality of scintillators are provided in one detector module 411.

  The light guide transmits the visible light generated by the scintillator to the photomultiplier. The light guide is formed of, for example, a plastic material having excellent light transmittance.

  The photomultiplier has a photocathode, a plurality of dynodes, and an anode. The photocathode receives the visible light output from the scintillator and generates photoelectrons by a photoelectric effect. The dynode generates an electric field for accelerating photoelectrons generated by the photocathode. Photoelectrons generated by the photocathode collide with the dynode and strike out a plurality of electrons from the dynode. Each of the plurality of ejected electrons collides with the next dynode, and ejects a plurality of electrons from the dynode. By repeating this phenomenon, many electrons enter the anode. The electrons incident on the anode become signal currents and are sent to the coincidence counting information collecting circuit 42. Here, the signal current is, for example, analog waveform data.

  The plurality of detector modules 411 described above are arranged in a cylindrical shape with the scintillator facing inward, and form the γ-ray detector 41.

  Based on the signal current sent from the detector module 411 included in the γ-ray detector 41, the coincidence information collecting circuit 42 determines the position of the scintillator to which the γ-ray has entered, the energy of the γ-ray that has entered the scintillator, and the γ-ray. Calculate the detected time. The position of the scintillator to which the set of gamma rays is incident, the energy of the gamma rays incident to the scintillator, and the time at which the gamma rays are detected, calculated by the coincidence counting information collecting circuit 42, are called counting information.

  The coincidence counting information collecting circuit 42 calculates the position of the scintillator on which the γ-ray has entered. Specifically, the coincidence counting information collecting circuit 42 corresponds to the positions of the plurality of photomultiplier tubes that have converted the plurality of visible lights output from the scintillator into signal currents at substantially the same timing, and the intensity of each of these electric signals. The position of the center of gravity is calculated from the energy of the γ-ray to be performed. Then, the coincidence counting information collecting circuit 42 specifies the position of the scintillator on which the γ-ray has entered from the calculated position of the center of gravity.

  The coincidence counting information collecting circuit 42 calculates the energy of the γ-ray incident on the scintillator. The coincidence counting information collecting circuit 42 calculates, for example, the wave height and the waveform area of each waveform included in the waveform data of the signal current output from the photomultiplier as the energy of the γ-ray incident on the scintillator.

  The coincidence counting information collecting circuit 42 calculates the time when the γ-ray is detected. For example, the coincidence counting information collection circuit 42 calculates the instant at which the current value exceeds a preset threshold value in the waveform data of the signal current as the time when the γ-ray is detected. The time at which the γ-ray is detected is, for example, an absolute time. The absolute time is a time. Alternatively, the time at which the γ-ray is detected may be a relative time from the start of capturing the functional image.

  The coincidence counting information collecting circuit 42 calculates the counting information by applying the above-described method to each scintillator included in each detector module 411.

  Next, the coincidence counting information collecting circuit 42 emits the γ rays of the calculated counting information in substantially the opposite directions due to the disappearance of each pair based on the detected time of the γ rays, and corresponds to the pair of the γ rays detected almost at the same time. The two pieces of counting information to be searched are searched. For example, the coincidence counting information collection circuit 42 collects, as coincidence counting information, two pieces of counting information in which the detected time difference is within a predetermined time window. That is, the coincidence counting information includes two pieces of counting information. The coincidence counting information is stored in a data storage circuit 53 described later as functional image data. Here, the functional image data is projection data for generating a functional image. Note that the coincidence counting information collecting circuit 42 may perform the above-described processing using the time window on the counting information within the range of the predetermined energy window. The coincidence counting information collecting circuit 42 is realized by, for example, a processor.

  As shown in FIG. 2, the console 5 includes an input circuit 51, a display 52, a data storage circuit 53, a storage circuit 54, and a processing circuit 55.

  The input circuit 51 is used by a user who inputs instructions and settings. The input circuit 51 is included in, for example, a mouse and a keyboard. The input circuit 51 transfers instructions and settings input by the user to the processing circuit 55. The input circuit 51 is realized by, for example, a processor.

  The display 52 is a monitor to which the user refers. The display 52 is, for example, a liquid crystal display. The display 52 receives from the processing circuit 55 an instruction to display, for example, morphological image data, functional image data, and a GUI (Graphical User Interface) used when the user inputs instructions and settings. Here, the morphological image data means an image itself indicating morphological information or data on which this image is displayed. Further, the functional image data means an image itself indicating functional information or data on which this image is displayed. The display 52 displays, for example, morphological image data, functional image data, and a GUI based on this instruction.

  The data storage circuit 53 stores, for example, the signals acquired by the signal acquisition circuit 23, the data for morphological images, and the data for functional images. The data storage circuit 53 stores, for example, morphological image data and functional image data.

  The storage circuit 54 stores a program for the drive circuit 22, the signal acquisition circuit 23, the data collection circuit 34, and the coincidence counting information collection circuit 42 to realize the functions described above. The storage circuit 54 stores a program for the processing circuit 55 to realize each function described later.

  Each of the data storage circuit 53 and the storage circuit 54 includes a storage medium from which stored information can be read by a computer. The storage medium is, for example, a hard disk.

  As shown in FIG. 2, the processing circuit 55 includes an adjustment function 550, a photographing control function 551, a morphological image data generating function 552, a functional image data generating function 553, a morphological image data collecting function 554, and a displacement calculating function 555. , A function image data collection function 556, a correction function 557, an image processing function 558, and a control function 559. Details of these functions will be described later. The processing circuit 55 is realized by, for example, a processor.

  Next, an example of a process performed by the medical image diagnostic apparatus 1 according to the first embodiment will be described with reference to FIGS. FIG. 3 is a flowchart illustrating an example of a process performed by the medical image diagnostic apparatus according to the first embodiment. FIG. 4 is a diagram for explaining the relationship between the collection period of the morphological image data, the collection period of the functional image data, and the signal acquired by the signal acquisition circuit according to the first embodiment. FIG. 5 is a diagram illustrating an example of a process performed by the medical image diagnostic apparatus according to the first embodiment.

  As shown in FIG. 3, the processing circuit 55 contributes to the collection period of the morphological image data that contributes to the generation of the morphological image data used to calculate the displacement of the morphological image region, and contributes to the generation of the corrected functional image data. The acquisition period of the functional image data is matched (step S1). Here, the collection period of the morphological image data is a period necessary for the morphological image data generation function 552 to collect the morphological image data necessary to generate one morphological image data. Further, the collection period of the functional image data is a period required for the functional image data generation function 553 to collect functional image data necessary for generating one functional image data. The process in step S1 is, for example, as follows.

  The processing circuit 55 reads a program corresponding to the adjustment function 550 from the storage circuit 54 and executes the program. The adjustment function 550 determines the collection period of the morphological image data and the function image that contributes to the generation of the functional image data to be corrected by the correction function 557 when the entire collection period of the morphological image data contributes to the generation of the morphological image data. Match the data collection period.

  As shown in FIG. 4, for each pulse of the heart of the subject P, n time phases T (1),..., T (k-1), T (k), T (K + 1),..., T (n) (n: a natural number of 2 or more, k: a natural number of 1 or more and n or less) are considered. Note that these time phases partially overlap the adjacent time phases before and after. In addition, the length and number of these time phases are restricted by the time required for the morphological image data imaging device 3 to make one rotation of the X-ray tube 31 and the X-ray detector 32 in order to collect morphological image data. .

  The adjustment function 550 adjusts the collection period of the morphological image data and the collection period of the functional image data to these phases. The adjusting function 550 adjusts the collection period C (k) of the data for morphological image and the collection period P (k) of the data for functional image to the time phase T (k), for example. .., C (k−1), C (k + 1),..., C (n) and the collection period P of the other functional image data. , P (k−1), P (k + 1),..., P (n) perform the same processing.

  As shown in FIG. 3, the processing circuit 55 collects morphological image data and functional image data of the target portion in each time phase (step S2). The process in step S2 is, for example, as follows.

  The processing circuit 55 reads out a program corresponding to the photographing control function 551 from the storage circuit 54 and executes it. The imaging control function 551 controls each component of the medical image diagnostic apparatus 1 to collect morphological image data and functional image data.

  The imaging control function 551 controls the drive circuit 22 to move the top plate 21 on which the subject P is placed into the imaging opening of the morphological image data imaging device 3. Then, the imaging control function 551 controls the signal acquisition circuit 23 to acquire a signal from the subject P, and causes the morphological image data photographing apparatus 3 to collect morphological image data of a target portion in the subject P. In this case, the morphological image data capturing apparatus 3 performs, for example, a conventional scan of the subject P. Next, the imaging control function 551 controls the drive circuit 22 to move the top board 21 on which the subject P is placed into the imaging opening of the functional image data imaging device 4. Then, the imaging control function 551 controls the signal acquisition circuit 23 to acquire a signal from the subject P, and causes the functional image data photographing apparatus 4 to collect data for a functional image of a target portion in the subject P. The morphological image data and the functional image data are stored in the data storage circuit 53.

  As shown in FIG. 3, the processing circuit 55 generates morphological image data of the target part in each time phase (step S3). The process in step S3 is, for example, as follows.

  The processing circuit 55 reads a program corresponding to the morphological image data generation function 552 from the storage circuit 54 and executes the program. The morphological image data generation function 552 reconstructs the morphological image data collected in step S2 and generates morphological image data.

  The morphological image data generation function 552 acquires morphological image data stored in the data storage circuit 53 and performs preprocessing. The pre-processing is, for example, logarithmic conversion, offset correction, sensitivity correction, beam hardening correction, and scattered radiation correction. The morphological image data generating function 552 stores the preprocessed morphological image data in the data storage circuit 53.

  The morphological image data generation function 552 reconstructs the preprocessed morphological image data and generates morphological image data. The reconstruction method is, for example, a back projection method. The back projection method is, for example, an FBP (Filtered Back Projection) method. Alternatively, the reconstruction method is a successive approximation method. The morphological image data generation function 552 reconstructs the morphological image data collected in step S2, for example, and generates the morphological image data K (1),..., K (k),. ). The morphological image data generation function 552 stores the generated morphological image data in the data storage circuit 53.

  The processing circuit 55 generates functional image data of the target part in each time phase as shown in FIG. 3 (Step S4). The process in step S4 is, for example, as follows.

  The processing circuit 55 reads out a program corresponding to the function image data generation function 553 from the storage circuit 54 and executes the program. The functional image data generation function 553 generates functional image data based on the functional image data collected in step S2.

  The functional image data generation function 553 reconstructs the functional image data stored in the data storage circuit 53 and generates functional image data. The functional information is, for example, a motion parameter of the target site and a parameter related to blood flow. The motion parameters of the target site are, for example, myocardial wall momentum and ejection fraction. The parameters related to the blood flow are, for example, the blood flow, the blood volume, the average transit time, and the washout rate.

  The reconstruction method is, for example, a successive approximation method. The successive approximation method is, for example, an MLEM (Maximum Likelihood Expectation Maximization) method or an OSEM (Ordered Subset MLEM) method. Note that the functional image data generation function 553 may perform reconstruction using a time-of-flight difference as performed in a TOF (Time of Flight) -PET apparatus. Here, the flight time difference is a time difference between detection times of coincidence counting information. The functional image data generation function 553 reconstructs the functional image data collected in the step, for example, and outputs the functional image data F (1),..., F (k),. Generate The function image data generation function 553 stores the generated function image data in the data storage circuit 53.

  As shown in FIG. 3, the processing circuit 55 collects morphological image data of the target part in each time phase (step S5). The processing circuit 55 reads a program corresponding to the morphological image data collection function 554 from the storage circuit 54 and executes the program. The morphological image data collection function 554 collects the morphological image data K (1),..., K (k),..., K (n) generated in step S3, for example.

  As shown in FIG. 3, the processing circuit 55 calculates the displacement of the morphological image area of the morphological image data based on the plurality of morphological image data (step S6). The process in step S6 is, for example, as follows.

  The processing circuit 55 reads out a program corresponding to the displacement calculation function 555 from the storage circuit 54 and executes it. The displacement calculation function 555 calculates the displacement of the morphological image area of the morphological image data based on the morphological image data collected in step S5.

  The displacement calculating function 555 uses the morphological image data K (1),..., T (T) of the temporal phase T (1) with reference to the morphological image data K (k) of the temporal phase T (k) shown in FIG. k-1) morphological image data K (k-1), temporal phase T (k + 1) morphological image data K (k + 1),..., temporal phase T (n) morphological image data K (n) Calculate the displacement of the area. Here, the morphological image region is a region of a plurality of pixels or pixels of the morphological image data. When the morphological image data is three-dimensional, the morphological image area is a three-dimensional area. When the morphological image data is two-dimensional, the morphological image area is a two-dimensional area.

  The displacement calculating function 555 includes the form image data K (1),... Of the phase T (1), the form image data K (k−1) of the phase T (k−1), and the form of the phase T (k + 1). The image data K (k + 1),..., The morphological image data K (n-1) or the morphological image data K (n) of the temporal phase T (n-1) and the temporal phase T as a reference The position of the morphological image area of the morphological image data is adjusted so that the mutual information (Mutual Information) with the morphological image data K (k) of (k) becomes as large as possible. The morphological image data in which the position of the morphological image area is adjusted is closer to the morphological image data K (k) of the reference time phase T (k) as the mutual information amount is larger.

  The displacement calculation function 555 adjusts the position of the morphological image area of these morphological image data by, for example, a position matching method or a point matching method. The positioning method may be either a linear positioning method or a non-linear positioning method. The linear registration method is a method of deforming the morphological image data without changing the distribution of the morphological image area. The linear alignment method is, for example, translation, rotation, enlargement, and reduction of the entire morphological image data. The non-linear positioning method is a method of transforming the morphological image data by changing the distribution of the morphological image area. The non-linear positioning method is, for example, translation, rotation, enlargement, or reduction of a part of the morphological image data. Further, the index indicating how close the morphological image data K (k) of the reference phase T (k) is is not limited to the mutual information amount.

  After adjusting the position of the morphological image area included in the morphological image data of each time phase, the displacement calculating function 555 records the displacement of each morphological image area before and after the adjustment. The displacement calculating function 555 records these displacements for each morphological image area included in the morphological image data. The displacement of the morphological image area recorded by such a method is also called a warpfield.

  For example, the warp field D (1) of the morphological image data K (1) shown in FIG. 5 is a set of displacement vectors before and after adjusting the position of each morphological image region included in the morphological image data K (1). The warp field D (n) of the morphological image data K (n) shown in FIG. 5 is a set of displacement vectors before and after adjusting the position of each morphological image region included in the morphological image data K (n). Further, all components of all displacement vectors included in the warp field D (k) of the morphological image data K (k) shown in FIG. 5 are zero. This is because the morphological image data K (k) is a reference for calculating the displacement of the morphological image area of each morphological image data. The displacement calculation function 555 stores these warp fields in the data storage circuit 53.

  As shown in FIG. 3, the processing circuit 55 collects functional image data of the target site in each time phase based on the radiation generated by the radiopharmaceutical present in the target site (step S7). The processing circuit 55 reads a program corresponding to the function image data collection function 556 from the storage circuit 54 and executes the program. The function image data collection function 556 collects, for example, the function image data F (1),..., F (k),.

  As shown in FIG. 3, the processing circuit 55 corrects the influence of the movement of the target part in the functional image data based on the displacement calculated in step S6 (step S8). The process in step S8 is, for example, as follows.

  The processing circuit 55 reads a program corresponding to the correction function 557 from the storage circuit 54 and executes the program. The correction function 557 corrects the position of the functional image area corresponding to the morphological image area in the functional image data based on the displacement in the time phase corresponding to the functional image data for correcting the effect of the movement of the target part.

  The correction function 557 moves each functional image area of the functional image data F (1) based on the warp field D (1) calculated in step S6, for example. Thereby, the correction function 557 generates the functional image data F (1, k) shown in FIG. The correction function image data F (1, k) is pseudo-moved by moving each function image area of the function image data F (1) of the time phase T (1) based on the warp field D (1). This corresponds to the generated functional image data F (k) of the time phase T (k). Also, the correction function 557 converts the correction function image data F (2, k),..., F (k−1, k), F (k + 1, k),. Generate.

  As shown in FIG. 3, the processing circuit 55 performs image processing on at least one of the functional image data and the corrected functional image data (Step S9). The process in step S9 is, for example, as follows.

  The processing circuit 55 reads out a program corresponding to the image processing function 558 from the storage circuit 54 and executes it. The image processing function 558 performs image processing on at least one of the function image data and the correction function image data.

  The image processing function 558 includes, for example, as shown in FIG. 5, the functional image data F (k) collected in step S7 and the corrected functional image data F (1, k),. .., F (n, k) are added together to generate added function image data S (k). The luminance of each functional image area of the addition function image data S (k) is the sum of the luminance of each morphological image area of the functional image data and the plurality of correction function image data. For this reason, the addition function image data S (k) expresses functional information of the subject P more clearly than the function image data and the correction function image data. Note that the image processing function 558 can arbitrarily select functional image data and correction function image data used for generating the addition function image data S (k).

  The image processing function 558 generates difference function image data by calculating a difference between the function image data in which the influence of the movement of the target part is corrected and the function image data before the influence of the movement of the target part is corrected. I do.

  Specifically, the image processing function 558 includes, for example, correction function image data F (1, k),..., F (k−1, k), F (k + 1, k),. k) or F (n, k) and the difference between the functional image data F (k) before the effect of the movement of the target portion is corrected, thereby generating differential functional image data. Alternatively, the image processing function 558 generates difference function image data by calculating a difference between the addition function image data S (k) and the function image data F (k), for example. .., F (k−1, k), F (k + 1, k),..., F (n, k) or the addition function image data S ( A visual representation of the difference between the position of each functional image area included in k) and the position of each functional image area included in the functional image data F (k) of the time phase T (k) used as a reference in step S6. I have. The image processing function 558 selects function image data and correction function image data to be used for generating the addition function image data S (k) based on an instruction input by the user as necessary, May be updated one by one.

  As shown in FIG. 3, the display 52 displays the image data generated in at least one of steps S3, S4, and S9 (step S10).

  The display 52 displays, for example, the morphological image data K (k) generated in step S3, the addition function image data S (k) and the difference function image data generated in step S9.

  As described above, the adjustment function 550 according to the first embodiment is configured such that when the entire collection period of morphological image data contributes to generation of morphological image data, the morphological image data collection period and the correction function 557 are used. The collection period of the functional image data that contributes to the generation of the functional image data to be corrected is matched. Accordingly, the medical image diagnostic apparatus 1 according to the first embodiment matches the collection period of the morphological image data with the collection period of the functional image data that contributes to the generation of the functional image data corrected by the correction function 557. Thus, it is possible to correct the influence of the movement of the target portion with higher accuracy than in the case where the influence of the movement of the target portion is corrected.

  The display 52 displays the difference function image data generated by calculating the difference between the function image data in which the influence of the movement of the target part is corrected and the function image data before correcting the influence of the movement of the target part. I do. Accordingly, the medical image diagnostic apparatus 1 according to the first embodiment determines the position of each functional image area included in the correction function image data or the addition function image data and the time phase T (k) used as a reference in step S6. The difference between the position of each functional image area of the functional image data F (k) and the position of each functional image area can be visually recognized by the user more easily than the superimposed functional image data described later. That is, the medical image diagnostic apparatus 1 according to the first embodiment can make the user recognize the accuracy of the correction performed in step S8 in FIG.

(Second embodiment)
A medical image diagnostic apparatus according to the second embodiment will be described. In the description of the second embodiment, the same reference numerals as those used in the description of the first embodiment are used. Note that detailed description of contents overlapping with the first embodiment is omitted.

  An example of a process performed by the medical image diagnostic apparatus 1 according to the second embodiment in step S1 in FIG. 3 will be described with reference to FIG. FIG. 6 is a diagram for explaining the relationship between the acquisition period of the morphological image data, the acquisition period of the functional image data, and the signal acquired by the signal acquisition circuit according to the second embodiment.

  When a part of the collection period of the morphological image data contributes to the generation of the morphological image data, the adjustment function 550 determines the time resolution of the morphological image data capturing device 3 that collects the morphological image data in step S1 of FIG. And the collection period of the functional image data that contributes to the generation of the functional image data to be corrected by the correction function 557. Here, the unit of the time resolution is, for example, “second”.

  As shown in FIG. 6, for each pulse of the heart of the subject P, n time phases T (1), T (2),..., T (k-1), T Consider the case where (k), T (k + 1),..., T (n) are set. Note that these time phases partially overlap the adjacent time phases before and after.

  In the second embodiment, the acquisition period of morphological image data in each time phase includes a time resolution and two preliminary periods, as shown in FIG. For example, as shown in FIG. 6, the acquisition period of the morphological image data in the time phase T (k) includes a preliminary period MF (k), a time resolution R (k), and a preliminary period MB (k). Further, the time resolution R (k) is equal to the length of the time phase T (k) as shown in FIG. The same applies to the other time phases T (1), T (2),..., T (k−1), T (k + 1),.

  However, the morphological image data generation function 552 does not use the portion of the morphological image data collected within the two preliminary periods for reconstruction. This is for the following reason.

  In some cases, the morphological image data generating function 552 reconstructs morphological image data by a back projection method, and the functional image data generating function 553 reconstructs functional image data by a successive approximation method. In this case, in order to reduce the influence due to the difference in the reconstruction method, the morphological image data generation function 552 performs, for example, the time resolution of the morphological image data before reconstructing the morphological image data by the back projection method. Is multiplied by a weight of 0.5 or more, and a portion of the morphological image data collected within two preliminary periods is multiplied by a weight of less than 0.5. Therefore, the portion of the morphological image data collected within the two preliminary periods has a small contribution to the morphological image data.

  In some cases, the morphological image data generating function 552 reconstructs morphological image data by a successive approximation method, and the functional image data generating function 553 reconstructs functional image data by a successive approximation method. The morphological image data photographing apparatus 3 needs to rotate the X-ray tube 31 and the X-ray detector 32 once to collect morphological image data. On the other hand, since the detector module 411 is arranged in a cylindrical shape, the functional image data photographing apparatus 4 can always collect functional image data around the subject P. In order to reduce the influence due to such a difference, the morphological image data generating function 552 may, for example, set the morphological image data within the range of the time resolution before reconstructing the morphological image data by the successive approximation method. The collected portion is weighted by 0.5 or more, and the portion of the morphological image data collected within two preliminary periods is weighted by less than 0.5. Therefore, the portion of the morphological image data collected within the two preliminary periods has a small contribution to the morphological image data.

  Therefore, the adjusting function 550 adjusts the collection period of the functional image data to each of n time phases. That is, the adjustment function 550 adjusts each acquisition period of the functional image data to each time resolution. The adjustment function 550 adjusts, for example, the acquisition period P (k) of the data for functional images to the time phase T (k). That is, the adjusting function 550 adjusts the time resolution R (k) to the time phase T (k), for example. The adjustment function 550 performs the same processing for the collection periods P (1), P (2),..., P (k−1), P (k + 1),. Do.

  As described above, the adjustment function 550 according to the second embodiment includes a morphological image data capturing device that collects morphological image data when a part of the collection period of morphological image data contributes to generation of morphological image data. And the collection period of the functional image data that contributes to the generation of the functional image data to be corrected by the correction function 557. In other words, the adjustment function 550 according to the second embodiment contributes to the generation of the morphological image data during the collection period of the morphological image data and the generation of the functional image data corrected by the correction function 557. The data collection period of the functional image data to be collected. Thus, the medical image diagnostic apparatus 1 according to the second embodiment can correct the influence of the movement of the target portion with higher accuracy than the medical image diagnostic apparatus 1 according to the first embodiment.

(Third embodiment)
A medical image diagnostic apparatus according to the third embodiment will be described. In the description of the third embodiment, the same reference numerals as those used in the description of the first embodiment are used. It should be noted that detailed description of contents overlapping with the above-described embodiment will be omitted. The morphological image data imaging apparatus 3 according to the third embodiment continuously irradiates the subject P with X-rays, and generates morphological image data of the heart of the subject P by segment reconstruction.

  An example of a process performed by the medical image diagnostic apparatus 1 according to the third embodiment in step S1 in FIG. 3 will be described with reference to FIGS. FIG. 7 illustrates a case where the R wave of the electrocardiographic signal of the subject is generated at regular intervals, the acquisition period of the morphological image data, the acquisition period of the functional image data, and the signal acquisition circuit according to the third embodiment. FIG. 4 is a diagram for explaining a relationship between acquired signals. FIG. 8 shows a case where the acquisition period of the morphological image data, the acquisition period of the functional image data, and the signal acquisition circuit according to the third embodiment when the R wave of the electrocardiographic signal of the subject does not occur at regular intervals. FIG. 4 is a diagram for explaining a relationship between acquired signals.

  When the morphological image data is generated by segment reconstruction, the adjustment function 550 calculates the average of the time resolution in each time phase of the morphological image data capturing device 3 that collects the morphological image data, and the correction function 557 corrects the average. The collection period of the functional image data that contributes to the generation of the functional image data is adjusted to the average.

  First, as shown in FIG. 7, a case is considered in which a time phase TS that appears periodically is set, and beats H11, H12, and H13 with equal R-wave intervals are generated.

  As shown in FIG. 7, the morphological image data photographing apparatus 3 according to the third embodiment converts morphological image data having a view from 0 ° to 120 ° in the time resolution CS (k−1) during the pulsation H11. Collect and collect morphological image data with a view from 120 degrees to 240 degrees in time resolution CS (k) during pulsation H12, and view from 240 degrees to 360 degree in time resolution CS (k + 1) during pulsation H13. Collect data for morphological images up to degree. The morphological image data generation function 552 reconstructs these three morphological image data and generates morphological image data of the time phase TS.

  In this case, the adjustment function 550 calculates an average of the time resolution CS (k−1), the time resolution CS (k), and the time resolution CS (k + 1) using a predetermined algorithm. This average is a time that is close to １ ／ of the time that the X-ray tube 31 makes one rotation around the subject P during scanning.

  Then, the adjustment function 550 adjusts the acquisition period of the functional image data that contributes to the generation of the functional image data to the above-described average in each of the beats H11, H12, and H13. Specifically, the adjustment function 550 adjusts the acquisition period PS (k-1) of the functional image data to the above-described average in the pulsation H11. Similarly, the adjustment function 550 adjusts the acquisition period PS (k) of the functional image data to the above-mentioned average in the pulsation H12. In the pulsation H13, the acquisition period PS (k + 1) of the functional image data is adjusted to the above-described average.

  Next, as shown in FIG. 8, a case will be considered in which a time phase TS that appears periodically is set, and pulsations H21, H22, and H23 having equal R-wave intervals are generated. The third R wave shown in FIG. 8 occurs at a timing later than in the case of a normal heartbeat. Therefore, the pulsation H22 shown in FIG. 8 is longer than the pulsation H12 shown in FIG. 7, and the pulsation H23 shown in FIG. 8 is shorter than H13 shown in FIG. The pulsation H21 shown in FIG. 8 has the same length as the pulsation H11 shown in FIG.

  As illustrated in FIG. 8, the morphological image data capturing apparatus 3 according to the third embodiment converts morphological image data having a view from 0 ° to 180 ° in the time resolution CU (k−1) during the pulsation H21. In the time resolution CU (k) during the pulsation H22, the view collects morphological image data from α degrees to β degrees (α ≠ 0 degrees, β ≠ 180 degrees), and the time resolution during the pulsation H23 In the CU (k + 1), morphological image data whose view is from 180 to 360 degrees is collected. The morphological image data generation function 552 reconstructs morphological image data with a view of 0 to 180 degrees and morphological image data with a view of 180 to 360 degrees, and generates morphological image data of the time phase TS. . That is, the morphological image data generation function 552 does not reconstruct morphological image data whose view is from α degrees to β degrees. This is because the third R-wave shown in FIG. 8 is generated at a later timing than in the case of a normal heartbeat, and the view of the morphological image data collected at the time resolution CU (k) during the pulsation H22. Is different from the intended view.

  In this case, the adjustment function 550 calculates an average of the time resolution CU (k-1) and the time resolution CU (k + 1) using a predetermined algorithm. This average is a time that is close to half the time that the X-ray tube 31 makes one rotation around the subject P during scanning.

  Then, the adjustment function 550 adjusts the collection period of the functional image data contributing to the generation of the functional image data to the above-described average in each of the beats H21 and H23. Specifically, the adjusting function 550 adjusts the acquisition period PS (k-1) of the functional image data to the above-described average in the pulsation H21. Similarly, in the beat H23, the acquisition period PS (k + 1) of the functional image data is adjusted to the above-described average.

  As described above, when the morphological image data is generated by segment reconstruction, the adjustment function 550 according to the third embodiment is configured to collect the morphological image data by using the morphological image data capturing apparatus. The average is calculated, and the collection period of the functional image data that contributes to the generation of the functional image data corrected by the correction function 557 according to the third embodiment is adjusted to the average. Accordingly, the medical image diagnostic apparatus 1 according to the third embodiment performs segment reconstruction, so that even when the time resolution of the morphological image data capturing apparatus 3 cannot be clearly defined, the medical image diagnostic apparatus 1 can accurately determine the target region. The effect of movement can be corrected.

  In the third embodiment, the case where the morphological image data imaging device 3 continuously irradiates the subject P with X-rays has been described as an example. However, the present invention is not limited to this. For example, the morphological image data capturing apparatus 3 according to the third embodiment includes a time resolution CS (k−1) during the pulsation H11, a time resolution CS (k) during the pulsation H12, and a time resolution during the pulsation H13. The subject P may be irradiated with X-rays only in CS (k + 1).

(Fourth embodiment)
A medical image diagnostic apparatus according to a fourth embodiment will be described. In the description of the fourth embodiment, the same reference numerals as those used in the description of the first embodiment are used. It should be noted that detailed description of contents overlapping with the above-described embodiment will be omitted. In the fourth embodiment, the adjustment function 550 does not perform the process of step S1 in FIG. Instead, in the fourth embodiment, the adjustment function 550 generates weighted addition function image data in step S8 in FIG. In the fourth embodiment, the correction function 557 is not the function image data collected by the function image data collection function 556 in step S8 of FIG. Correct the movement of.

  An example of a process performed by the medical image diagnostic apparatus 1 according to the fourth embodiment in step S8 in FIG. 3 will be described with reference to FIG. FIG. 9 is a diagram for explaining the relationship between the collection period of the morphological image data, the collection period of the functional image data, and the signal acquired by the signal acquisition circuit according to the fourth embodiment.

  The adjustment function 550 performs the following processing before the correction function 557 corrects the position of the functional image area included in the functional image data in step S8 of FIG. That is, the adjustment function 550 determines that the collection period of the functional image data that contributes to the generation of the functional image data is the collection period of the morphological image data that contributes to the generation of the morphological image data used by the displacement calculation function 555 for calculating the displacement. The weighted addition of the functional image data is performed in accordance with the period in which the function image data overlaps, thereby performing a process of generating the weighted added functional image data.

  As shown in FIG. 9, for one beat of the heart of the subject P, n time phases U (1), U (2),. Consider the case where (k), U (k + 1),..., U (n) are set. Note that these time phases do not overlap with the adjacent time phases.

  In the fourth embodiment, the acquisition period of the morphological image data in each time phase is longer than each time phase, as shown in FIG. For example, as shown in FIG. 9, the acquisition period CW (k) of the morphological image data in the time phase U (k) is longer than the time phase U (k). On the other hand, the collection period of the functional image data in each time phase is equal to the length of each time phase, as shown in FIG. For example, as shown in FIG. 9, the acquisition period PU (k) of the functional image data in the time phase U (k) is equal to the length of the time phase U (k). The same applies to other time phases U (1), T (2),..., T (k−1), T (k + 1),.

  The adjustment function 550 includes, for example, a function image data collection period PU (k−1), a function image data collection period PU (k), and a function image collected by the function image data collection function 556 in step S7 of FIG. Each of the functions of the functional image data corresponding to the collection period of the functional image data in accordance with the period overlapping the collection period CW (k) of the morphological image data with respect to the collection period PU (k + 1) of the functional data Weights the brightness of the image area.

  As shown in FIG. 9, the entire collection period PU (k) of the functional image data overlaps with the collection period CW (k) of the morphological image data. Therefore, the adjustment function 550 multiplies the brightness of each functional image area included in the functional image data corresponding to the functional image data collection period PU (k) by a weight “1”. As shown in FIG. 9, the last quarter of the collection period PU (k-1) of the functional image data overlaps with the collection period CW (k) of the morphological image data. Thus, the adjustment function 550 multiplies the weight of each functional image area included in the functional image data corresponding to the functional image data collection period PU (k−1) by the weight “0.25”. As shown in FIG. 9, the first quarter of the functional image data collection period PU (k + 1) overlaps the morphological image data collection period CW (k). Therefore, the adjustment function 550 multiplies the weight of each functional image area included in the functional image data corresponding to the functional image data collection period PU (k + 1) by the weight “0.25”.

  Then, the adjustment function 550 adds the luminance of each functional image area of the three functional image data obtained by multiplying the luminance of each functional image area by weight, and generates weighted addition functional image data.

  The correction function 557 corrects the movement of the target portion in the weighted addition function image data based on the displacement calculated by the displacement calculation function 555 in step S8 of FIG. Specifically, the correction function 557 determines the position of the functional image area corresponding to the morphological image area in the addition function image data based on the displacement in the time phase corresponding to the addition function image data for correcting the effect of the movement of the target part. Is corrected. The details of this correction are as described above.

  As described above, the adjustment function 550 according to the fourth embodiment is different from the adjustment function 550 in that the collection period of the functional image data contributing to the generation of the functional image data is the generation of the morphological image data used by the displacement calculating function 555 for calculating the displacement. The weighted addition function image data is generated by weighting and adding the function image data according to the period overlapping with the collection period of the morphological image data contributing to the image data. That is, the adjustment function 550 according to the fourth embodiment simulates the collection period of the morphological image data and the collection period of the functional image data by weighting and adding the functional image data. Then, the correction function 557 according to the fourth embodiment corrects the influence of the movement of the target part in the weighted addition function image data.

  Accordingly, in the medical image diagnostic apparatus 1 according to the fourth embodiment, for example, the time during which the morphological image data capturing apparatus 3 rotates the X-ray tube 31 and the X-ray detector 32 one time is caused by the speed of the target portion. Even when the collection period of the morphological image data and the collection period of the functional image data cannot be directly matched due to the restriction, the movement of the target part can be performed with high accuracy as in the medical image diagnostic apparatus 1 according to the above-described embodiment. Can be corrected. Alternatively, even when the generation of the morphological image data and the functional image data has already been completed, the medical image diagnostic apparatus 1 according to the fourth embodiment has the same high accuracy as the medical image diagnostic apparatus 1 according to the above-described embodiment. Can correct the effect of the movement of the target part.

(Fifth embodiment)
A medical image diagnostic device according to a fifth embodiment will be described. In the description of the fifth embodiment, the same reference numerals as those used in the description of the first embodiment are used. It should be noted that detailed description of contents overlapping with the above-described embodiment will be omitted. In the fifth embodiment, the adjustment function 550 does not perform the process of step S1 in FIG. Instead, in the fifth embodiment, the adjustment function 550 calculates a weighted displacement in step S8 of FIG. Further, in the fifth embodiment, the correction function 557 corrects the influence of the movement of the target portion in the functional image data based on the weighted displacement in step S8 in FIG.

  An example of the processing performed by the correction function 557 according to the fifth embodiment in step S8 in FIG. 3 will be described with reference to FIGS. FIG. 10 is a diagram for explaining the relationship between the collection period of morphological image data, the collection period of functional image data, and signals acquired by the signal acquisition circuit according to the fifth embodiment. FIG. 11 is a diagram illustrating an example of a process performed by the medical image diagnostic apparatus according to the fifth embodiment.

  The adjustment function 550 determines in step S8 of FIG. 3 that the collection period of the morphological image data that contributes to the generation of the morphological image data used by the displacement calculating function 555 for calculating the displacement is the function image that contributes to the generation of the functional image data. A weighted displacement is calculated by weighting and adding the displacement in accordance with a period that overlaps with the data collection period.

  As shown in FIG. 10, for each pulse of the heart of the subject P, n time phases T (1), T (2),..., T (k−1), T Consider the case where (k), T (k + 1),..., T (n) are set. Note that these time phases partially overlap the adjacent time phases before and after.

  In the fifth embodiment, the acquisition period of the morphological image data in each time phase is equal to the length of each time phase, as shown in FIG. For example, as shown in FIG. 10, the collection period C (k) of the functional image data in the time phase T (k) is equal to the length of the time phase T (k). On the other hand, the collection period of the functional image data in each time phase is longer than each time phase as shown in FIG. For example, as shown in FIG. 10, the collection period PW (k) of the functional image data in the time phase T (k) is longer than the time phase T (k). The same applies to the other time phases T (1), T (2),..., T (k−1), T (k + 1),.

  The adjustment function 550 is, for example, a collection period of the morphological image data that contributes to the generation of the morphological image data K (k−2), K (k−1), K (k + 1), and K (k + 2) illustrated in FIG. C (k−2), C (k−1), C (k + 1) and C (k + 2) depend on the period in which the functional image data F (k) overlaps with the functional image data collection period PW (k). Then, weights are applied to the displacement vectors of the warp fields D (k-2), D (k-1), D (k + 1) and D (k + 2) shown in FIG. Here, the warp fields D (k−2), D (k−1), D (k + 1) and D (k + 2) illustrated in FIG. 11 are calculated by the displacement calculating function 555 based on the morphological image data K (k). , Morphological image data K (k-2), K (k-1), K (k + 1), and K (k + 2) by adjusting the position of each morphological image region.

  As shown in FIG. 10, in the collection period C (k−2) of the morphological image data that contributes to generation of the morphological image data K (k−2), the last １ ／ of the functional image data F (k) The period overlaps with the collection period PW (k) of the functional image data that contributes to generation. Therefore, the adjusting function 550 multiplies the warp field D (k−2) shown in FIG. 11 by the weight “0.25”. In the collection period C (k-1) of the morphological image data that contributes to the generation of the morphological image data K (k-1), the last 3/4 of the collection period C (k-1) for the functional image that contributes to the generation of the functional image data F (k) It overlaps with the data collection period PW (k). Therefore, the adjustment function 550 multiplies the warp field D (k−1) shown in FIG. 11 by the weight “0.75”.

  The collection period C (k + 1) of the morphological image data that contributes to the generation of the morphological image data K (k + 1) is the first 3/4 of the collection period of the functional image data that contributes to the generation of the functional image data F (k). It overlaps with PW (k). Therefore, the adjustment function 550 multiplies the warp field D (k + 1) shown in FIG. 11 by the weight “0.75”. In the collection period C (k + 2) of the morphological image data that contributes to the generation of the morphological image data K (k + 2), the first quarter is the collection period of the functional image data that contributes to the generation of the functional image data F (k). It overlaps with PW (k). Therefore, the adjusting function 550 multiplies the warp field D (k + 2) shown in FIG. 11 by the weight “0.25”.

  The adjusting function 550 calculates, for example, the weighted warp field DW (k) shown in FIG. 11 by adding the respective displacement vectors of the four warp fields that have been weighted.

  The correction function 557 corrects the influence of the movement of the target part in the functional image data based on the weighted displacement in step S8 in FIG. Specifically, the correction function 557 determines the position of the functional image area corresponding to the morphological image area of the morphological image data K (k) in the functional image data F (k) based on the weighted warp field DW (k). To generate the correction function image data A (k) shown in FIG. The details of this correction are as described above.

  The adjustment function 550 sets the other weighted warp fields as the acquisition periods C (1),..., C (n) of the morphological image data that contribute to the generation of the morphological image data K (1),. ) And the collection period PW (1),..., PW (n) of the functional image data that contributes to the generation of the functional image data F (1),. It is calculated by adding. The correction function 557 corrects the influence of the motion of the target part on the functional image data F (1),..., F (n) based on each weighted warp field, and generates corrected functional image data.

  As described above, the adjustment function 550 according to the fifth embodiment is different from the adjustment function 550 in that the collection period of the morphological image data that contributes to the generation of the morphological image data used by the displacement calculating function 555 for the calculation of the displacement corresponds to the generation of the functional image data. The weighted displacement is calculated by weighting and adding the displacement in accordance with the period that overlaps with the collection period of the functional image data that contributes to. That is, the adjustment function 550 according to the fifth embodiment uses the weighted displacement to correct the effect of the movement of the target part in the functional image data, thereby obtaining the morphological image data collection period and the functional image data collection. Pseudo-match the period. Then, the correction function 557 according to the fifth embodiment corrects the influence of the movement of the target part in the functional image data based on the weighted displacement, whereby the medical image diagnostic apparatus 1 according to the fifth embodiment An effect equivalent to that of the medical image diagnostic apparatus 1 according to the fourth embodiment is achieved.

  In step S9 of FIG. 1, instead of the differential function image data described in the first embodiment, the image processing function 558 determines the function image data obtained by correcting the effect of the movement of the target part and the effect of the movement of the target part. The superimposed functional image data may be generated by superimposing the functional image data before correction. The image processing function 558 includes, for example, correction function image data F (1, k),..., F (k−1, k), F (k + 1, k),. By superimposing S (k) and functional image data F (k), superimposed functional image data is generated. Further, the display 52 may display superimposed function image data instead of the difference function image data described in the first embodiment in step S10 of FIG.

  Accordingly, the medical image diagnostic apparatus 1 according to any one of the first to fifth embodiments determines the position of each functional image area included in the correction function image data or the addition function image data, and in step S6. The user can easily and visually recognize the difference between the position of each functional image area included in the functional image data F (k) of the reference time phase T (k). That is, the medical image diagnostic apparatus 1 according to the first embodiment can make the user recognize the accuracy of the correction performed in step S8 in FIG.

  The display 52 displays the information indicated by the functional image data in which the correction function 557 has corrected the effect of the movement of the target portion in step S10 of FIG. 1, and the functional image data before the correction function 557 has corrected the effect of the movement of the target portion. May be displayed as an index indicating a difference from the information indicated by. This index is, for example, the mutual information amount between the information indicated by the functional image data in which the correction function 557 has corrected the influence of the movement of the target portion and the functional image data before the correction function 557 has corrected the influence of the movement of the target portion. It is.

  Accordingly, the medical image diagnostic apparatus 1 according to any one of the first to fifth embodiments determines the position of each functional image area included in the correction function image data or the addition function image data, and in step S6. It is possible to make the user quantitatively recognize the difference between the position of each functional image area included in the functional image data F (k) of the reference time phase T (k).

  In the first to fifth embodiments, the case where the morphological image data imaging device 3 and the functional image data imaging device 4 perform electrocardiographic synchronous imaging of the heart of the subject P has been described as an example. Not done. The embodiment described above can be applied, for example, when the morphological image data imaging device 3 and the functional image data imaging device 4 perform respiratory synchronization imaging of the lungs of the subject P.

  When an abnormality occurs in the signal of the subject P, the morphological image data collection function 554 does not have to collect the morphological image data in the entire cycle in which the abnormality has occurred in step S5 of FIG. Alternatively, when an abnormality occurs in the signal of the subject P, the morphological image data collection function 554 does not have to collect the morphological image data at the time when the abnormality occurs in step S5 in FIG. Thereby, in the medical image diagnostic apparatus 1 according to any one of the first to fifth embodiments, the displacement calculated in step S6 in FIG. 3 becomes an inaccurate displacement due to a signal abnormality. Can be avoided.

  When an abnormality occurs in the signal of the subject P, the function image data collection function 556 does not have to collect the function image data of the entire cycle in which the abnormality has occurred in step S5 of FIG. Alternatively, when an abnormality occurs in the signal of the subject P, the functional image data collection function 556 does not have to collect the functional image data at the time when the abnormality occurs in step S5 in FIG. Thereby, the medical image diagnostic apparatus 1 according to any one of the first embodiment to the fifth embodiment recognizes that the correction performed in step S8 in FIG. 3 is incorrect due to the signal abnormality. Can be avoided.

  An example of a process performed by the medical image diagnostic apparatus 1 according to any one of the first embodiment to the fifth embodiment instead of the processes of steps S8 and S9 in FIG. 3 will be described with reference to FIG. I do. FIG. 12 is a view for explaining an example of processing performed by the medical image diagnostic apparatus according to any one of the first to fifth embodiments in place of the processing of steps S8 and S9 in FIG. It is.

  As shown in FIG. 12, the medical image diagnostic apparatus 1 according to any one of the first embodiment to the fifth embodiment performs a time phase TP (k) in a predetermined range of each beat of the heart of the subject P. ) Will be described as an example in which the morphological image data K (k) and the functional image data F (k) are generated. Here, the time phase TP (k) in the predetermined range is, for example, a heartbeat phase of 45% to 55% of each beat of the heart of the subject P.

  In step S8 of FIG. 3, the correction function 557 chronologically compares the warp field of the time phase TP (k) before and after the time phase TP (k) of each beat and the warp field D (k) of the time phase TP (k). Then, the time change of the displacement of each morphological image area included in the morphological image data is derived. Next, the correction function 557 calculates a differential coefficient and a difference in the time phase TP (k) of the displacement of each morphological image region included in the morphological image data based on this time change. Then, the correction function 557 corrects the position of the functional image area of the functional image data F (k) in each beat using the differential coefficient and the difference, and generates corrected functional image data FC (k). .

  In step S9 of FIG. 3, the image processing function 558 adds the brightness of each function image area of the correction function image data FC (k) for each beat, for example, as shown in FIG. (K) is generated. The brightness of each functional image area of the addition function image data Σ (k) is the sum of the brightness of each morphological image area of the correction function image data FC (k) in each beat. Therefore, the addition function image data Σ (k) clearly expresses functional information of the subject P more clearly than the correction function image data FC (k) in each beat.

  In the first to fifth embodiments, the case where the morphological image data capturing device 3 is an X-ray CT device and the functional image data capturing device 4 is a PET device has been described as an example. Not limited. For example, the morphological image data imaging device 3 may be a magnetic resonance imaging device. Further, the functional image data imaging device 4 may be another nuclear medicine imaging device such as a SPECT device.

  The above-described processor is, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an application specific integrated circuit (ASIC), a programmable logic device (Programmable Logic Device: PLD), a field programmable gate array. (Field Programmable Gate Array: FPGA). Further, the programmable logic device (PLD) is, for example, a simple programmable logic device (SPLD) or a complex programmable logic device (CPLD).

  In the above-described embodiment, the drive circuit 22, the signal acquisition circuit 23, the data collection circuit 34, the coincidence counting information collection circuit 42, and the processing circuit 55 read out and execute the program stored in the storage circuit 54 to perform their functions. , But is not limited to this. Instead of storing the program in the storage circuit 54, the program may be directly incorporated in each of these circuits. In this case, these circuits realize their functions by reading and executing a directly incorporated program.

  Each circuit illustrated in FIG. 2 may be appropriately dispersed or integrated. For example, the processing circuit 55 includes an adjustment function 550, a shooting control function 551, a morphological image data generating function 552, a functional image data generating function 553, a morphological image data collecting function 554, a displacement calculating function 555, a functional image data collecting function 556, and a correction. The function 557, the image processing function 558, and the control function 559 may be distributed to circuits that execute the respective functions. That is, the processing circuit 55 includes an adjustment circuit, a photographing control circuit, a morphological image data generation circuit, a functional image data generation circuit, a morphological image data collection circuit, a displacement calculation circuit, a functional image data collection circuit, a correction circuit, an image processing circuit, and control. It may be distributed in a circuit. Further, the drive circuit 22, the signal acquisition circuit 23, the data collection circuit 34, the coincidence counting information collection circuit 42, and the processing circuit 55 may be arbitrarily integrated.

  According to at least one embodiment described above, it is possible to generate functional image data in which the influence of the movement of the target portion is reduced.

  Although several embodiments of the present invention have been described, these embodiments are provided by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and equivalents thereof.

554 Morphological image data collection function 555 Displacement calculation function 556 Function image data collection function 557 Correction function 550 Adjustment function

Claims (12)

A morphological image data collection unit that collects morphological image data of the target part in each time phase,
Based on a plurality of the morphological image data, a displacement calculation unit that calculates the displacement of the morphological image region that the morphological image data has,
In a period different from the period in which the plurality of morphological image data is collected , based on radiation generated by a radiopharmaceutical present in the target site, functional image data to collect functional image data of the target site in each time phase A collection unit,
Based on the displacement, a correction unit that corrects the effect of the movement of the target portion in the functional image data,
The acquisition period of the morphological image data that contributes to the generation of the morphological image data used by the displacement calculator to calculate the displacement, and the functional image data that contributes to the generation of the functional image data corrected by the correction unit. An adjustment unit that adjusts the collection period to the same phase ,
A medical image diagnostic apparatus comprising:   The correction unit corrects the position of the functional image area corresponding to the morphological image area in the functional image data based on the displacement in the time phase corresponding to the functional image data for correcting the effect of the movement of the target portion. The medical image diagnostic apparatus according to claim 1, wherein: The adjustment unit may be configured to perform the collection period of the morphological image data and the generation of the functional image data corrected by the correction unit when all of the collection period of the morphological image data contributes to the generation of the morphological image data. The medical image diagnostic apparatus according to claim 1 or 2, wherein the contributing functional image data collection period is set to the same time phase . The adjustment unit, when a part of the collection period of the morphological image data contributes to the generation of the morphological image data , among the collection period of the morphological image data, a period that contributes to the generation of the morphological image data, 3. The medical image diagnostic apparatus according to claim 1, wherein the correction unit adjusts a collection period of the functional image data that contributes to generation of the functional image data to be corrected. 4. When the morphological image data is generated by segment reconstruction, the adjustment unit calculates, for each time phase, an average of a period contributing to generation of the morphological image data, among collection periods of the morphological image data , The medical image diagnostic apparatus according to claim 1, wherein a collection period of the functional image data contributing to generation of the functional image data corrected by the correction unit in each time phase is adjusted to the average. The adjustment unit is configured so that the collection period of the functional image data that contributes to the generation of the functional image data is the morphological image data that contributes to the generation of the morphological image data used by the displacement calculator to calculate the displacement. According to the period overlapping with the collection period, by weighting and adding the functional image data, to generate weighted addition functional image data,
The medical image diagnostic apparatus according to claim 1, wherein the correction unit corrects an influence of a motion of the target part in the weighted addition function image data. The adjustment unit is configured such that the acquisition period of the morphological image data that contributes to the generation of the morphological image data used by the displacement calculation unit for the calculation of the displacement is the collection period of the functional image data that contributes to the generation of the functional image data. According to a period overlapping with the collection period, a weighted displacement is calculated by weighting and adding the displacement,
The medical image diagnostic apparatus according to claim 1, wherein the correction unit corrects an influence of a movement of the target portion in the functional image data based on the weighted displacement. The correction unit generates difference function image data by calculating a difference between the function image data in which the influence of the movement of the target part is corrected and the function image data before correcting the influence of the movement of the target part. An image processing unit for
A display unit for displaying the difference function image data,
The medical image diagnostic apparatus according to any one of claims 1 to 7, further comprising: The correction unit superimposes the functional image data on which the influence of the movement of the target part has been corrected and the functional image data before correcting the influence of the movement of the target part, thereby generating superimposed functional image data. An image processing unit;
A display unit that displays the superimposition function image data,
The medical image diagnostic apparatus according to any one of claims 1 to 7, further comprising:   The correction unit displays an index indicating a difference between the information indicated by the functional image data in which the influence of the movement of the target part has been corrected and the information indicated by the functional image data before correcting the influence of the movement of the target part. The medical image diagnostic apparatus according to any one of claims 1 to 7, further comprising a display unit configured to perform the operation.   The medical image diagnostic apparatus according to claim 10, wherein the display unit displays a mutual information amount as the index. A morphological image data collection unit that collects morphological image data of the target part in each time phase,
Based on a plurality of the morphological image data, a displacement calculation unit that calculates the displacement of the morphological image region that the morphological image data has,
In a period different from the period in which the plurality of morphological image data is collected , based on radiation generated by a radiopharmaceutical present in the target site, functional image data to collect functional image data of the target site in each time phase A collection unit,
Based on the displacement, a correction unit that corrects the effect of the movement of the target portion in the functional image data,
The acquisition period of the morphological image data that contributes to the generation of the morphological image data used by the displacement calculator to calculate the displacement, and the functional image data that contributes to the generation of the functional image data corrected by the correction unit. An adjustment unit that adjusts the collection period to the same phase ,
A medical image processing apparatus comprising:

Images