JP5582798B2 - Medical image diagnostic apparatus, X-ray CT apparatus, and image processing apparatus - Google Patents

Description

  The present invention relates to a medical image diagnostic apparatus, an X-ray CT apparatus, and an image processing apparatus.

  In recent years, imaging is performed during a period in which the subject has stopped breathing (hereinafter referred to as a breathing stop period) as one of the techniques for imaging a part that moves with breathing, such as a chest organ or abdominal organ, as a target part. There is a technique (for example, Patent Document 1). For example, the medical image diagnostic apparatus images a target part in time series during the breathing stop period. For example, when an instruction such as “please hold your breath” is given to the patient, the patient stops breathing, and the medical image diagnostic apparatus images the target region in time series. For example, when an instruction such as “please make it easy” is given to the patient, the patient breathes and the medical image diagnostic apparatus interrupts the imaging.

  As described above, the breathing stop period is often provided in several times with the breathing gap interposed therebetween, but the target part is a part that moves with breathing, and therefore there is a risk of positional deviation between the image data. There is. For this reason, conventionally, a medical image diagnostic apparatus selects image data serving as a reference for alignment from a plurality of acquired image data, and sets the amount of movement between the selected image data and each of all other image data, respectively. Calculation and alignment are performed.

JP 2003-116843 A

  However, the above-described conventional technique has a problem that the number of times of calculating the movement amount is large, and the processing time that must be taken for alignment is long.

  The present invention has been made in view of the above, and an object of the present invention is to provide a medical image diagnostic apparatus, an X-ray CT apparatus, and an image processing apparatus that can shorten the processing time for alignment. .

In order to solve the above-described problems and achieve the object, the medical image diagnostic apparatus according to the embodiment images a part moving with breathing in time series for each period in which the subject stops breathing. it is an imaging means for obtaining image data group in each said period of time, from the image data groups each of each said period of time taken by the imaging means, at least one selected image data to be representative of each image data group Selection means, reference selection means for selecting image data as a reference for alignment from all image data, and image data that is representative of each image data group selected by the selection means are selected by the reference selection means. The amount of movement from the reference image data is calculated, alignment is performed using the calculated amount of movement, and the same image data as the representative image data is used. The other image data belonging to the data group, characterized by comprising alignment means for performing alignment by using the amount of movement. In addition, the medical image diagnostic apparatus according to the embodiment acquires a group of image data in each period by capturing, in time series, a part that moves with the breath for each period in which the subject stops breathing. Representative of at least one of the first imaged image data and the last imaged image data in each of the image data groups from each of the imaging unit and the image data group for each period imaged by the imaging unit The selection means for selecting as image data, and the movement between the image data captured last in the preceding period and the image data captured first in the subsequent period for the adjacent periods in time series The amount is calculated, alignment is performed using the calculated amount of movement, and the amount of movement is used for other image data belonging to the same image data group as the representative image data. Characterized in that a positioning means for aligning.

In addition, the X-ray CT apparatus according to the embodiment acquires a group of image data in each period by imaging in time series the part that moves with respiration for each period in which the subject stops breathing. Imaging means, selection means for selecting at least one image data representative of each image data group from each of the image data groups for each period imaged by the imaging means, and image data serving as a reference for alignment Calculating from the reference image data selected by the reference selection means for the reference selection means for selecting the image data from all the image data and the image data representative of each image data group selected by the selection means Then, alignment is performed using the calculated movement amount, and the other image data belonging to the same image data group as the representative image data is transferred. Characterized in that a positioning means for performing positioning using the amounts. In addition, the X-ray CT apparatus according to the embodiment acquires a group of image data in each period by imaging in time series the part that moves with respiration for each period in which the subject stops breathing. Representative of at least one of the first imaged image data and the last imaged image data in each of the image data groups from each of the imaging unit and the image data group for each period imaged by the imaging unit The selection means for selecting as image data, and the movement between the image data captured last in the preceding period and the image data captured first in the subsequent period for the adjacent periods in time series The amount is calculated, alignment is performed using the calculated amount of movement, and other image data belonging to the same image data group as the representative image data is used for the position adjustment using the amount of movement. Characterized in that a positioning means for performing combined.

In addition, the image processing apparatus according to the embodiment includes each image data from each image data group for each period in which a part that moves with respiration is imaged in time series for each period in which the subject stops breathing. A selection means for selecting at least one image data representing the group ; a reference selection means for selecting image data serving as a reference for alignment from all the image data; and a representative of each image data group selected by the selection means For the image data to be obtained, a movement amount from the reference image data selected by the reference selection unit is calculated, alignment is performed using the calculated movement amount, and the same image data as the representative image data is obtained. Alignment means for aligning other image data belonging to the group using the movement amount is provided. In addition, the image processing apparatus according to the embodiment includes each image data from an image data group for each period in which a part that moves with respiration is captured in time series for each period in which the subject stops breathing. The selection means for selecting at least one of the first captured image data and the last captured image data as representative image data in the group, and the time period adjacent to each other in the preceding period The amount of movement between the image data picked up in the image and the image data picked up first in the subsequent period is calculated, alignment is performed using the calculated amount of movement, and representative image data Alignment means for aligning other image data belonging to the same image data group using the movement amount is provided.

According to at least one embodiment , it is possible to shorten the processing time for alignment.

FIG. 1 is a block diagram illustrating the configuration of the X-ray CT apparatus according to the first embodiment. FIG. 2 is a diagram for explaining an imaging plan executed in the first embodiment. FIG. 3 is a diagram for explaining an example of image data. FIG. 4 is a diagram for explaining an example of alignment. FIG. 5 is a flowchart illustrating a processing procedure performed by the image processing unit according to the first embodiment. FIG. 6 is a diagram for explaining an example of alignment. FIG. 7 is a flowchart illustrating a processing procedure performed by the image processing unit according to the second embodiment. FIG. 8 is a diagram for explaining the image processing apparatus.

  Embodiments of a medical image diagnostic apparatus, an X-ray CT apparatus, and an image processing apparatus according to the present invention will be described in detail below. In addition, this invention is not limited by the following examples.

[Configuration of X-ray CT Apparatus According to Embodiment 1]
In the first embodiment, an X-ray CT apparatus will be described as an example of a medical image diagnostic apparatus. As a specific imaging example, a method is assumed in which a contrast medium is injected into a chest organ and the chest organ is imaged in time series for each respiratory stop period. First, the configuration of the X-ray CT apparatus according to the first embodiment will be described with reference to FIGS. FIG. 1 is a block diagram illustrating the configuration of the X-ray CT apparatus according to the first embodiment.

  As shown in FIG. 1, the X-ray CT apparatus 100 according to the first embodiment includes a gantry device 10, a couch device 20, and a console device 30. As will be described later, the X-ray CT apparatus 100 according to the first embodiment includes an image processing unit 39 in the console device 30, and the image processing unit 39 captures image data captured in time series for each respiratory stop period. Processing will be performed.

  The gantry device 10 is a device that irradiates the subject P with X-rays, detects X-rays that have passed through the subject P, and outputs the X-rays to the console device 30. The gantry device 10 includes a high-voltage generator 11, an X-ray tube 12, An X-ray detector 13, a data collection unit 14, a rotating frame 15, and a gantry driving unit 16 are included.

  The high voltage generator 11 supplies a high voltage to the X-ray tube 12. The X-ray tube 12 is a vacuum tube and generates X-rays by a high voltage supplied from the high voltage generator 11. The X-ray detector 13 detects X-rays that have passed through the subject P. The data collection unit 14 generates projection data using the X-rays detected by the X-ray detector 13. The rotating frame 15 is an annular frame that supports the X-ray tube 12 and the X-ray detector 13 so as to face each other with the subject P interposed therebetween, and rotates at high speed and continuously. The gantry driving unit 16 rotates the rotary frame 15 by driving the motor, and rotates the X-ray tube 12 and the X-ray detector 13 on a circular orbit around the subject P.

  The couch device 20 is a table on which the subject P to be imaged is placed, and includes a couchtop 21 and a couch driving unit 22. The top plate 21 is a plate on which the subject P is placed. The bed driving unit 22 moves the top plate 21 by driving a motor. Specifically, the bed driving unit 22 moves the table 21 in the direction toward the gantry device 10 (slice direction) and in the opposite direction, the up-down direction, and the left-right direction.

  The console device 30 accepts an operation of the X-ray CT apparatus 100 by the operator and reconstructs an image from the projection data collected by the gantry device 10. Specifically, the console device 30 includes an input device 31, a display device 32, a scan control unit 33, a preprocessing unit 34, a projection data storage unit 35, an image reconstruction processing unit 36, and an image data storage. A unit 37, a system control unit 38, and an image processing unit 39.

  The input device 31 is a mouse, a keyboard, or the like, and receives an instruction input to the X-ray CT apparatus 100 from an operator. For example, the input device 31 receives imaging condition settings, image processing instructions, and the like.

  The display device 32 is a display such as an LCD (Liquid Crystal Display) and displays various types of information. For example, the display device 32 displays an image stored in the image data storage unit 37, a GUI (Graphical User Interface) for receiving an instruction from the operator, and the like.

  The system control unit 38 controls the X-ray CT apparatus 100 as a whole by controlling the gantry device 10, the couch device 20, and the console device 30. For example, the system control unit 38 controls the scan control unit 33 to collect projection data, and controls the image reconstruction processing unit 36 to reconstruct an image from the projection data. When the system control unit 38 receives an image processing instruction from the operator via the input device 31, the system control unit 38 controls the image processing unit 39 to execute the image processing. The system control unit 38 is, for example, an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), or an electronic circuit such as a CPU (Central Processing Unit) or MPU (Micro Processing Unit). is there.

  The scan control unit 33 controls the high voltage generation unit 11, the data collection unit 14, and the gantry driving unit 16 based on the imaging condition instructed from the system control unit 38. The scan control unit 33 controls the bed driving unit 22 under the control of the system control unit 38. The scan control unit 33 is, for example, an integrated circuit such as an ASIC or FPGA, or an electronic circuit such as a CPU or MPU.

  Here, the imaging example assumed in Example 1 is demonstrated easily using FIG. FIG. 2 is a diagram for explaining an imaging plan executed in the first embodiment. FIG. 2 shows an imaging plan screen displayed on the display device 32. The vertical axis indicates the amount of X-ray output, and the horizontal axis indicates time. In addition, characters “Start” and “End” and a speaker mark are displayed on the upper part of the imaging plan screen. When these speaker marks come to corresponding times, for example, “Please hold your breath.” And instructions such as “Please make it easy” are given to the patient.

  In Example 1, a contrast medium is injected into a chest organ, and the chest organ is imaged in time series for each respiratory stop period. Specifically, as shown in FIG. 2, the entire imaging time is 126 seconds, and four breathing stop periods (P1, P2, P3, P4) sandwiching three breaths are provided therebetween, A plurality of X-ray exposures are performed every breathing stop period.

  For example, the first breathing stop period P1 is from 13 seconds to 31 seconds, and 10 X-ray exposures are performed in time series during that period. The second respiratory stop period P2 is from 37 seconds to 61 seconds, and during that time, seven X-ray exposures are performed in time series. Further, the third breathing stop period P3 is from 69 seconds to 93 seconds, and during that time, four X-ray exposures are performed in time series. The fourth respiratory stop period P4 is 101 seconds to 121 seconds, and three X-ray exposures are performed in time series during that period. The number of exposures per respiratory stop period gradually decreases, but this is planned as appropriate, for example, in relation to the degree of penetration of the contrast medium into the chest organ.

  The breathing period is between the first respiratory stop period P1 and the second respiratory stop period P2, and between the second respiratory stop period P2 and the third respiratory stop period P3, and the third respiratory stop. It is provided between the period P3 and the fourth respiratory stop period P4.

  Returning to FIG. 1, the preprocessing unit 34 performs preprocessing such as sensitivity correction on the projection data generated by the data collection unit 14, and stores the projection data after the preprocessing in the projection data storage unit 35. The preprocessing unit 34 is, for example, an integrated circuit such as an ASIC or FPGA, or an electronic circuit such as a CPU or MPU.

  The projection data storage unit 35 stores the projection data that has been preprocessed by the preprocessing unit 34. The projection data storage unit 35 is, for example, a semiconductor memory device such as a RAM (Random Access Memory), a ROM (Read Only Memory), and a flash memory, a hard disk, an optical disk, or the like.

  The image reconstruction processing unit 36 reconstructs an image from the projection data stored in the projection data storage unit 35 based on the reconstruction condition instructed by the system control unit 38, and adds incidental information to the reconstructed image data. The image data to which the attached information is attached is stored in the image data storage unit 37.

  The image data storage unit 37 stores the image data reconstructed by the image reconstruction processing unit 36. The image data storage unit 37 is, for example, a semiconductor memory element such as a RAM, a ROM, or a flash memory, a hard disk, an optical disk, or the like.

  Here, an example of the image data stored in the image data storage unit 37 will be described with reference to FIG. FIG. 3 is a diagram for explaining an example of image data. As shown in FIG. 3, the image data storage unit 37 stores incidental information and image data (such as a volume image) in association with each other. Here, the incidental information is information added to image data in accordance with, for example, DICOM (Digital Imaging and Communications in Medicine) standard. For example, the DICOM standard stipulates that patient information, three-stage information of a study, a series, and an image are added as incidental information.

  In FIG. 3, illustration of the commonly attached supplementary information is omitted, and only one example of supplementary information provided in the first embodiment is illustrated. That is, the image data storage unit 37 stores the number of exposures, the exposure time, and the breathing stop period as incidental information.

  Next, the image processing unit 39 will be described. As described above, the image processing unit 39 processes image data captured in time series for each respiratory stop period. Specifically, the image processing unit 39 performs image processing on the image data, controls display of the image data, and causes the display device 32 to display the image data.

  This point will be described in detail. As shown in FIG. 1, the image processing unit 39 includes a reference image data selection unit 39a, a representative image data selection unit 39b, an alignment unit 39c, and a display control unit 39d. .

  The reference image data selection unit 39a selects image data (hereinafter referred to as reference image data) serving as a reference for alignment from all image data. Specifically, the reference image data selection unit 39a according to the first embodiment first reads the entire image data group with reference to the image data storage unit 37 based on an instruction from the system control unit 38. For example, the reference image data selection unit 39a reads an image data group as shown in FIG.

  Next, the reference image data selection unit 39a selects reference image data from all the image data according to a predetermined rule. For example, it is assumed that a predetermined rule is a rule in which image data captured at an intermediate position in time series is set as reference image data. Then, according to this rule, the reference image data selection unit 39a divides “24” of the “number of exposures” of the incidental information by “2” and sets the image data whose “number of exposures” is “12” as the reference image data. select. That is, the reference image data selection unit 39a selects the second image data as the reference image data in the image data group whose “respiration stop period” is “second”.

  Then, the reference image data selection unit 39a sends information on the selected reference image data to the representative image data selection unit 39b.

  Note that the rules described above can be arbitrarily changed, for example, a rule that uses image data captured at a position about 1/3 from the top in the time series as reference image data. can do.

  In the first embodiment, the method in which the reference image data selection unit 39a selects the reference image data according to a predetermined rule has been described. However, the present invention is not limited to this. For example, the selection is accepted from the operator. Also good. For example, the reference image data selection unit 39 a outputs all image data read from the image data storage unit 37 to the display device 32. Then, for example, the operator browses all image data, selects image data that seems to have the best contrast, and inputs selection information via the input device 31. Then, the reference image data selection unit 39a selects the image data designated by the selection information received as input as the reference image data.

  The representative image data selection unit 39b selects at least one image data that represents each image data group (hereinafter referred to as representative image data) from each image data group for each respiratory stop period. Specifically, the representative image data selection unit 39b selects one representative image data from each of the image data groups for each respiratory arrest period read from the image data storage unit 37 by the reference image data selection unit 39a.

  For example, the representative image data selection unit 39b determines whether the “breathing stop period” of the supplementary information is located before or after the “second time” in which the reference image data is selected. Then, the representative image data selection unit 39b selects, as the representative image data, the image data captured last in this breathing stop period when positioned before, and the breathing stop period when positioned later. The image data picked up first is selected as representative image data. That is, the representative image data selection unit 39b according to the first embodiment selects image data that is close in time series to the reference image data as representative image data of each image data group.

  For example, the representative image data selection unit 39b determines that the image data group for 10 sheets in which the “breathing stop period” of the supplementary information is “first time” is positioned before the “second time” in time series, The image data that was captured last in the first respiratory stop period (image data with the “exposure time” of the supplementary information “31”) is selected as representative image data.

  Further, for example, the representative image data selection unit 39b determines that the image data group for four images whose “breathing stop period” in the supplementary information is “third time” is positioned later in time series than “second time”. Image data captured first in the third breathing stop period (image data with “exposure time” of “69”) is selected as representative image data.

  In addition, for example, the representative image data selection unit 39b determines that the image data group for three images whose “breathing stop period” is “fourth” is positioned later in time series than “second”, and the fourth time Image data first captured during the breathing stop period (image data with “exposure time” of “101”) is selected.

  Then, the representative image data selection unit 39b sends information on the selected image data to the alignment unit 39c.

  In the first embodiment, the representative image data selection unit 39b determines whether the reference image data is positioned before or after the “breathing stop period” in which the reference image data is selected, and depends on the determination result. The method of selecting representative image data has been described above, but the method is not limited to this. The representative image data selection unit 39b may arbitrarily select the representative image data regardless of whether the reference image data is positioned before or after the “breathing stop period” in time series. In the first embodiment, the method in which the representative image data selection unit 39b selects one representative image data has been described. However, the present invention is not limited to this. The representative image data selection unit 39b may select two or more representative image data. However, since it is “representative”, it does not select all the image data belonging to the image data group.

  The alignment unit 39c uses the representative image data selected by the representative image data selection unit 39b to perform alignment between image data included in different breathing stop periods. Specifically, the alignment unit 39c first calculates a movement amount from the reference image data for the representative image data, and performs alignment using the calculated movement amount. Next, the alignment unit 39c aligns the other image data belonging to the same image data group as the representative image data using this movement amount.

  Then, the alignment unit 39c sends each image data group after the alignment to the display control unit 39d. The alignment is realized by a known technique. For example, the alignment unit 39c moves the position of the other image data in units of pixels with reference to one image data, and obtains the amount of movement moved until the similarity between the image data becomes the highest. Then, the alignment unit 39c corrects the other image data using the obtained movement amount.

  Here, an example of alignment in the first embodiment will be described with reference to FIG. FIG. 4 is a diagram for explaining an example of alignment. In FIG. 4, the number of image data belonging to the image data group is omitted for convenience of explanation. For example, as illustrated in FIG. 3, the number of image data groups in which the “breathing stop period” is “first time” is ten, but only four are illustrated in FIG. 4 (see the breathing stop period P1). ).

  The arrow in FIG. 4A indicates that the second image data is selected as the reference image data in the second respiratory stop period P2. Here, as shown in (B1) of FIG. 4, for example, the alignment unit 39c calculates the movement amount “movement amount 1” from the reference image data for the representative image data in the breathing stop period P1. Similarly, the alignment unit 39c calculates, for example, the movement amount “movement amount 2” from the reference image data for the representative image data in the breathing stop period P3, and the reference image data in the breathing stop period P4. The movement amount “movement amount 3” from the image data is calculated.

  Then, as shown in (B2) of FIG. 4, the alignment unit 39c corrects the representative image data of the respiratory stop period P1 using “movement amount 1”, and uses the “movement amount 2” to correct the respiratory stop period. The representative image data of P3 is corrected, and the representative image data of the respiratory stop period P4 is corrected using “movement amount 3”. Thus, as shown in (B2) of FIG. 4, the representative image data of the respiratory stop period P1, the representative image data of the respiratory stop period P3, and the representative image data of the respiratory stop period P4 are “after alignment”.

  Subsequently, as shown in (C1) of FIG. 4, the alignment unit 39c corrects other image data (other image data other than the representative image data) of the breathing stop period P1 using “movement amount 1”. Then, the other image data of the breathing stop period P3 is corrected using “movement amount 2”, and the other image data of the breathing stop period P4 is corrected using “movement amount 3”. This correction for other image data is a correction using the already calculated “movement amount 1”, “movement amount 2”, and “movement amount 3”, so that the amount of calculation is small and it is possible in a short processing time. is there.

  In this way, as shown in (C2) of FIG. 4, all the image data in the breathing stop period P1, all the image data in the breathing stop period P3, and all the image data in the breathing stop period P4 are “after alignment”.

  The display control unit 39d performs control so that each of the image data groups after the alignment is displayed continuously. Specifically, the display control unit 39d controls the display device 32 to display each image data group after the alignment sent from the alignment unit 39c is continuously displayed.

  Here, the technical meaning of the processing of the image processing unit 39 in the first embodiment will be described. The image processing unit 39 according to the first embodiment indicates that “the part that moves with breathing moves largely before and after breathing but hardly moves during the breathing stop period”. The misalignment between the image data is small enough to be ignored ”, and the alignment is omitted.

  Then, the image processing unit 39 performs the alignment between the image data included in the different breathing stop periods without omitting in view of “the part that moves with breathing moves largely before and after breathing”. In the first embodiment, one representative image data is selected from each respiratory stop period, a movement amount from the reference image data is calculated for the representative image data, and the position of other image data is calculated using the calculated movement amount. Explained how to combine. According to this method, since all the image data is aligned using the movement amount from the reference image data common to all the image data, the positional deviation of all the image data can be reduced.

  However, it is not limited to this method. Since the positional deviation between the image data included in the same breathing stop period is negligibly small, which image data is selected as the representative image data of each breathing stop period and a plurality of images from each breathing stop period. Whether or not to select data is arbitrary.

[Processing Procedure by Image Processing Unit in First Embodiment]
Next, a processing procedure by the image processing unit in the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart illustrating a processing procedure performed by the image processing unit according to the first embodiment.

  First, in the image processing unit 39, the reference image data selection unit 39a refers to the image data storage unit 37 based on an instruction from the system control unit 38, and reads all the image data groups for each respiratory stop period (step S101).

  Next, the reference image data selection unit 39a selects reference image data from all the image data read in step S101, and sends information on the selected reference image data to the representative image data selection unit 39b (step S102).

  Subsequently, the representative image data selection unit 39b selects representative image data from each of the image data groups for each breathing stop period, and sends information on the selected representative image data to the alignment unit 39c (step S103).

  Then, the alignment unit 39c calculates a movement amount from the reference image data for the representative image data selected by the representative image data selection unit 39b, and performs alignment using the calculated movement amount (step S104).

  The alignment unit 39c aligns other image data belonging to the same image data group as the representative image data using the movement amount calculated in step S104, and the image data after the alignment is performed. Each group is sent to the display control unit 39d (step S105).

  Then, the display control unit 39d performs control so as to continuously display each image data group after the alignment is performed, and displays a moving image on the display device 32 (step S106).

[Effect of Example 1]
As described above, the X-ray CT apparatus 100 according to the first embodiment images a part that moves with respiration (for example, a chest organ) in time series for each respiratory stop period. In addition, the X-ray CT apparatus 100 selects at least one image data that represents each image data group from each image data group for each respiratory stop period. Next, the X-ray CT apparatus 100 performs alignment between image data included in different breathing stop periods using the selected representative image data. Then, the X-ray CT apparatus 100 performs control so that each of the image data groups after the alignment is displayed continuously.

  The X-ray CT apparatus 100 according to the first embodiment includes a reference image data selection unit 39a that selects reference image data from all image data, and the alignment unit 39c moves the representative image data from the reference image data. , And the registration is performed using the calculated amount of movement, and the other image data belonging to the same image data group as the representative image data is aligned using the amount of movement.

  For this reason, according to the first embodiment, the number of times of alignment is reduced, and the processing time for alignment can be shortened. For example, when X-ray exposure is performed 24 times as in the first embodiment, conventionally, it is necessary to calculate the movement amount 23 times excluding selected specific image data. However, according to the first embodiment, the calculation of the movement amount only needs to be performed, for example, three times (the other image data is correction using the calculated movement amount, and the processing time is short). If it becomes possible to shorten the alignment processing time, for example, it becomes possible to improve the efficiency of analysis processing of test results in a hospital, leading to the efficiency of the entire medical treatment.

  Further, the image data in the first embodiment is provided with supplementary information indicating a breathing stop period in which the image data is captured, and the X-ray CT apparatus 100 according to the first embodiment is different using the supplementary information. Alignment between image data included in the breathing stop period is performed. For this reason, according to the first embodiment, it is possible to easily and reliably select image data.

  In the first embodiment, one representative image data is selected from each respiratory stop period, a movement amount from the reference image data is calculated for the representative image data, and the position of other image data is calculated using the calculated movement amount. Although the method of performing the combination has been described, the present invention is not limited to this. In the second embodiment, a method will be described in which image data captured first or last in each image data group is selected as representative image data, and alignment is performed for every two adjacent periods in time series.

  For example, the representative image data selection unit 39b according to the second embodiment performs image data captured last in the first respiratory stop period for the first respiratory stop period, which is the first respiratory stop period in time series. (Image data whose “exposure time” in the incidental information is “31”) is selected as representative image data. In addition, the representative image data selection unit 39b, for the respiratory stop period “fourth” that is the last respiratory stop period in time series, is the image data (the supplementary information of the supplementary information) that is first captured in the fourth respiratory stop period. “Image data with“ exposure time ”of“ 101 ”) is selected as representative image data.

  In addition, the representative image data selection unit 39b, for the respiratory stop periods “second time” and “third time” that are neither the first nor the last in time series, the first captured image data and the last captured image data. Both are selected as representative image data. For example, for the respiratory stop period “second time”, the representative image data selection unit 39b first captures image data captured during the second respiratory stop period (an image with an “exposure time” of the incidental information “37”). Data) and the last imaged image data (image data whose “exposure time” in the supplementary information is “61”) are selected as representative image data. In addition, for example, the representative image data selection unit 39b, for the respiratory stop period “third time”, the image data (“exposure time” in the supplementary information is “69” first captured in the third respiratory stop period). Image data) and the last imaged image data (image data with an “exposure time” of the auxiliary information of “93”) are selected as representative image data.

  Then, the representative image data selection unit 39b sends information on the selected image data to the alignment unit 39c, as in the first embodiment.

  Similar to the first embodiment, the alignment unit 39c according to the second embodiment uses the representative image data selected by the representative image data selection unit 39b to perform alignment between image data included in different respiratory stop periods. However, the alignment unit 39c according to the second embodiment firstly, for the adjacent periods in time series, between the image data captured last in the preceding period and the image data captured first in the subsequent period. The movement amount is calculated, and alignment is performed using the calculated movement amount. Next, the alignment unit 39c aligns the other image data belonging to the same image data group as the representative image data using this movement amount.

  The alignment unit 39c according to the second embodiment first performs the alignment for the period adjacent to the breathing stop period to which the reference image data belongs, and then the position for the period adjacent to the breathing stop period after the alignment. Align. That is, the alignment unit 39c sequentially expands the alignment period before and after the time series centering on the breathing stop period to which the reference image data belongs.

  Here, an example of alignment in the second embodiment will be described with reference to FIG. FIG. 6 is a diagram for explaining an example of alignment. In FIG. 6, the number of image data belonging to the image data group is omitted for convenience of explanation.

  The arrow in FIG. 6A indicates that the second image data is selected as the reference image data in the second respiratory stop period P2. Here, as illustrated in (B1) of FIG. 6, the alignment unit 39c, for example, for the representative image data in the respiratory stop period P1, moves from the representative image data (first) in the respiratory stop period P2 to “moving amount”. 1 ”is calculated. Similarly, the alignment unit 39c calculates, for example, the amount of movement “movement amount 2” from the representative image data (last) in the respiratory stop period P2 for the representative image data (first) in the respiratory stop period P3.

  Then, as shown in (B2) of FIG. 6, the alignment unit 39c corrects the representative image data of the respiratory stop period P1 using “movement amount 1”, and uses the “movement amount 2” to correct the respiratory stop period. The representative image data of P3 is corrected. Thus, as shown in (B2) of FIG. 6, the representative image data in the respiratory stop period P1 and the representative image data (first) in the respiratory stop period P3 are “after alignment”.

  Subsequently, as illustrated in (C1) of FIG. 6, the alignment unit 39c corrects other image data (other image data other than the representative image data) of the respiratory stop period P1 using “movement amount 1”. Then, other image data of the breathing stop period P3 is corrected using the “movement amount 2”. This correction for the other image data is a correction using the already calculated “movement amount 1” and “movement amount 2”, so that the amount of calculation is small and can be performed in a short processing time.

  In this way, as shown in (C2) of FIG. 6, all the image data in the breathing stop period P1 and all the image data in the breathing stop period P3 are “after alignment”.

  Next, the alignment unit 39c according to the second embodiment sequentially expands the alignment period before and after the time series, with the respiratory stop period P2 to which the reference image data belongs as the center. That is, as shown in (D1) of FIG. 6, since there is a breathing stop period P4 that is adjacent to the already stopped breathing stop period P3, the positioning unit 39c is shown in (D1) of FIG. As described above, the movement amount “movement amount 3 ′” from the representative image data (last) in the preceding respiratory stop period P3 is calculated for the representative image data in the respiratory stop period P4.

  Then, as illustrated in (D2) of FIG. 6, the alignment unit 39c corrects the representative image data in the breathing stop period P4 using “movement amount 3 ′”. Thus, as shown in (D2) of FIG. 6, the representative image data in the breathing stop period P4 is “after alignment”.

  Subsequently, as illustrated in (E1) of FIG. 6, the alignment unit 39c uses the “movement amount 3 ′” to obtain other image data (other image data other than the representative image data) of the breathing stop period P4. to correct. This correction for other image data is a correction using the already calculated “movement amount 3 ′”, so that the calculation amount is small and can be performed in a short processing time. In this way, as shown in (E2) of FIG. 6, all the image data in the respiratory stop period P4 is “after alignment”.

  Here, the technical meaning of the processing of the image processing unit 39 in the second embodiment will be described. As in the first embodiment, the image processing unit 39 according to the second embodiment “a portion that moves with breathing moves largely before and after breathing, but hardly moves during the breathing stop period”. The misalignment between the image data included in the same breathing stop period is negligibly small ”, and the alignment is omitted.

  Then, in the same way as in the first embodiment, the image processing unit 39 according to the second embodiment is configured to perform processing between image data included in different respiratory stop periods in view of “the part that moves with breathing moves largely before and after breathing”. Alignment is performed without omission. Here, in the second embodiment, a method has been described in which image data captured first or last is selected as representative image data from each respiratory stop period, and alignment is performed for each respiratory period adjacent in time series. According to this method, alignment can be performed with higher accuracy.

  That is, when the influence of the contrast agent is taken into consideration, the image data belonging to the adjacent respiratory stop periods are more similar to the situation of the contrast agent. For example, the contrast agent is gradually injected at the start of imaging, and is gradually discharged after a certain point in time. In view of such “gradual” injection and “gradual” discharge, it can be said that image data belonging to adjacent respiratory stop periods are more similar to the contrast medium. If so, when using the method of calculating the movement amount using the similarity between the two image data, the similarity is obtained by removing factors other than the movement amount, that is, factors such as differences in the status of the contrast agent. Should be measured. In other words, for example, even if the amount of movement itself is not so large, if the contrast agent situation is greatly different, the similarity between the two image data will show a low value, and the amount of movement is calculated. It is not measured correctly for the purpose.

  In this regard, according to the method of the second embodiment, since the movement amount is calculated between the image data belonging to the adjacent breathing stop periods in which the conditions of the contrast agent are approximate, it is possible to perform alignment with higher accuracy. In the second embodiment, the alignment period is sequentially expanded before and after the time series, with the respiratory stop period to which the reference image data belongs as the center. This is because the respiratory stop period to which the reference image data belongs is considered to be best imaged, so that the respiratory stop period is set as a reference respiratory stop period.

  The present invention is not limited to this. For example, without selecting the reference image data, the first or last imaged data is selected as representative image data from each respiratory stop period, and the data is selected from the front in the time series, from the back in order, or in any order. The method of aligning may be used.

  In the second embodiment, the movement amount is calculated for image data belonging to a breathing stop period adjacent to a certain breathing stop period, and the image data belonging to the breathing stop period is aligned using the calculated movement amount. Later, for the image data belonging to the respiratory stop period adjacent to the post-alignment respiratory stop period, a method of calculating the movement amount from the image data belonging to the post-alignment respiratory stop period was used. However, the present invention is not limited to this. For example, the movement amount between adjacent respiratory stop periods may be calculated in advance.

  For example, it is assumed that the movement amount between the image data group belonging to the respiratory stop period P2 and the image data group belonging to the respiratory stop period P3 is “movement amount A”. On the other hand, it is assumed that the movement amount between the image data group belonging to the respiratory stop period P3 and the image data group belonging to the respiratory stop period P4 is “movement amount B”. In this case, the movement amount used for the alignment of the image data group belonging to the respiratory stop period P4 can be calculated as “movement amount A + B”.

[Processing Procedure by Image Processing Unit in Embodiment 2]
Next, a processing procedure by the image processing unit in the second embodiment will be described with reference to FIG. FIG. 7 is a flowchart illustrating a processing procedure performed by the image processing unit according to the second embodiment.

  First, in the image processing unit 39, the reference image data selection unit 39a refers to the image data storage unit 37 based on an instruction from the system control unit 38, and reads all the image data groups for each respiratory stop period (step S201).

  Next, the reference image data selection unit 39a selects reference image data from all the image data read in step S201, and sends information on the selected reference image data to the representative image data selection unit 39b (step S202).

  Subsequently, the representative image data selection unit 39b selects the first image data and the last image data as representative image data from each of the image data groups for each breathing stop period, and aligns the information of the selected representative image data with the alignment unit. 39c (step S203).

  Then, the alignment unit 39c calculates the movement amount between the representative image data of the preceding respiratory stop period and the representative image data of the subsequent respiratory stop period for the respiratory stop periods that are adjacent in time series. Position alignment is performed using the movement amount (step S204).

  Further, the alignment unit 39c aligns the other image data belonging to the same image data group as the representative image data using the movement amount calculated in step S204 (step S205).

  Subsequently, the alignment unit 39c determines whether or not the alignment has been completed for the entire breathing stop period (step S206). If it is determined that the alignment has not ended (No at step S206), the alignment unit 39c again performs step S204. Return to the process. That is, the alignment unit 39c calculates the movement amount between the representative image data of the preceding respiratory stop period and the representative image data of the subsequent respiratory stop period for the respiratory stop periods that are further adjacent in time series. Alignment is performed using the moved amount (step S204), and other image data belonging to the same image data group as the representative image data is aligned using the moved amount calculated in step S204 (step S205). .

  If it is determined in step S206 that the processing has been completed (Yes in step S206), the alignment unit 39c sends the image data groups after the alignment to the display control unit 39d.

  Then, the display control unit 39d performs control so as to continuously display each image data group after the alignment is performed, and displays a moving image on the display device 32 (step S207).

[Effect of Example 2]
As described above, in the X-ray CT apparatus 100 according to the second embodiment, the representative image data selection unit 39b uses the image data captured first in each image data group or the last image as representative image data. Selected image data. In addition, the alignment unit 39c calculates a movement amount between the image data captured last in the preceding period and the image data captured first in the subsequent period for the adjacent periods in time series. Then, alignment is performed using the calculated movement amount. Further, the alignment unit 39c performs alignment for other image data belonging to the same image data group as the representative image data using the calculated movement amount.

  For this reason, according to the second embodiment, in addition to the effects of the first embodiment, it is possible to perform alignment with higher accuracy. According to the second embodiment, when the display control unit 39d continuously reproduces each image data group, it is possible to realize smooth moving image reproduction.

  In addition, the present invention may be implemented in various different forms other than the above-described embodiments.

[Image processing device]
In the first and second embodiments, an example has been described in which the X-ray CT apparatus, which is a medical image diagnostic apparatus, includes the image processing unit 39 that processes image data captured in time series for each respiratory stop period. The invention is not limited to this. For example, an X-ray CT apparatus and an image processing apparatus are connected to each other via a PACS (Picture Archiving and Communication System) network, and image data captured by the X-ray CT apparatus is transmitted to the image processing apparatus for image processing. The apparatus may be configured to process image data.

  In the case of such a configuration, for example, as shown in FIG. 8, the image processing apparatus 40 includes a reference image data selection unit 40a, a representative image data selection unit 40b, an alignment unit 40c, and a display control unit 40d. Then, the reference image data selection unit 40a selects reference image data from all the image data. In addition, the representative image data selection unit 40b selects at least one image data that represents each image data group from each of the image data groups for each breathing stop period. Further, the alignment unit 40c performs alignment between image data included in different breathing stop periods using the selected image. Further, the display control unit 40d performs control so as to continuously display each of the image data groups after the alignment. FIG. 8 is a diagram for explaining the image processing apparatus.

[Types of medical diagnostic imaging equipment]
In the first and second embodiments, an X-ray CT apparatus is assumed as the medical image diagnostic apparatus, but the present invention can be similarly applied to other medical image diagnostic apparatuses. For example, it can be applied to a medical image diagnostic apparatus such as an MRI (Magnetic Resonance Imaging) apparatus.

[Select representative image data]
The selection of representative image data is not limited to the method of the first and second embodiments. For example, representative image data to be selected may be received as a preset at the time of imaging planning. For example, it is assumed that the operator selects representative image data for each breathing stop period and inputs selection information during imaging planning. Since the selection information input by the operator is stored in the storage unit, the representative image data selection unit 39b refers to the selection information stored in the storage unit and selects the representative image data according to the referenced selection information. Good.

100 X-ray CT apparatus 39 Image processing unit 39a Reference image data selection unit 39b Image data selection unit 39c Positioning unit 39d Display control unit

Claims (8)

For each period in which the subject has stopped breathing, an imaging means for acquiring image data groups in each of the periods by imaging a part that moves with breathing in time series;
A selection means for selecting at least one image data representative of each image data group from each of the image data groups for each period imaged by the imaging means;
Reference selection means for selecting image data as a reference for alignment from all image data;
For the image data that is representative of each image data group selected by the selection unit, a movement amount from the reference image data selected by the reference selection unit is calculated, and alignment is performed using the calculated movement amount. A medical image diagnostic apparatus comprising: a positioning unit configured to perform positioning using the movement amount for other image data belonging to the same image data group as the representative image data . For each period in which the subject has stopped breathing, an imaging means for acquiring image data groups in each of the periods by imaging a part that moves with breathing in time series;
Image data representative of at least one of image data captured first and image data captured last in each image data group from each of the image data groups captured by the imaging means for each period. A selection means to select;
For time periods that are adjacent in time series, calculate the amount of movement between the image data last captured in the preceding period and the image data first captured in the subsequent period, and use the calculated amount of movement. Positioning means for performing positioning using the amount of movement for other image data belonging to the same image data group as representative image data;
A medical image diagnostic apparatus comprising: The medical image diagnosis according to claim 1 or 2, characterized in that positioning is further comprising a display control means for displaying consecutively the image data group, respectively, after made by the alignment means apparatus. The image data is provided with supplementary information indicating a period during which the image data was captured,
Said alignment means, using the supplementary information, the medical image diagnostic apparatus according to any one of claims 1 to 3, characterized in that the alignment between the image data contained in the different periods. In each period in which the subject has stopped breathing, by imaging the region that moves with the breathing in time series, an imaging means for obtaining image data group in each said period of time,
A selection means for selecting at least one image data representative of each image data group from each of the image data groups for each period imaged by the imaging means;
Reference selection means for selecting image data as a reference for alignment from all image data;
For the image data that is representative of each image data group selected by the selection unit, a movement amount from the reference image data selected by the reference selection unit is calculated, and alignment is performed using the calculated movement amount. An X-ray CT apparatus comprising: a positioning unit configured to perform positioning using the movement amount for other image data belonging to the same image data group as representative image data . For each period in which the subject has stopped breathing, an imaging means for acquiring image data groups in each of the periods by imaging a part that moves with breathing in time series;
Image data representative of at least one of image data captured first and image data captured last in each image data group from each of the image data groups captured by the imaging means for each period. A selection means to select;
For time periods that are adjacent in time series, calculate the amount of movement between the image data last captured in the preceding period and the image data first captured in the subsequent period, and use the calculated amount of movement. Positioning means for performing positioning using the amount of movement for other image data belonging to the same image data group as representative image data;
An X-ray CT apparatus comprising: At least one image data representative of each image data group is obtained from each image data group for each period in which a part that moves with respiration is imaged in time series for each period in which the subject stops breathing. A selection means to select;
Reference selection means for selecting image data as a reference for alignment from all image data;
For the image data that is representative of each image data group selected by the selection unit, a movement amount from the reference image data selected by the reference selection unit is calculated, and alignment is performed using the calculated movement amount. And an alignment unit that aligns the other image data belonging to the same image data group as the representative image data by using the movement amount . Image data first captured in each image data group from each of the image data groups for each period in which the part that moves with breathing is captured in time series for each period in which the subject stops breathing And a selection means for selecting at least one of the last imaged image data as representative image data;
For time periods that are adjacent in time series, calculate the amount of movement between the image data last captured in the preceding period and the image data first captured in the subsequent period, and use the calculated amount of movement. Positioning means for performing positioning using the amount of movement for other image data belonging to the same image data group as representative image data;
An image processing apparatus comprising:

Images