JP2009153677A - Kinetic image processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a kinetic image processing system to provide data effective for the diagnosis of the ventilation capacity of the lung. <P>SOLUTION: In the kinetic image processing system, the breast part of a subject is subjected to kinetic photographing by a photographing apparatus to form kinetic images in a plurality of time phases (Step S1) and an area change ratio is calculated at each region of a plurality of the split regions of the lung field region contained in each of the kinetic images using each of the kinetic images by the image analyzing part of an image processor and the normality or abnormality of a ventilation capacity of the lung is determined on the basis of the area change ratio (Step S3). Further, the position and name of an anatomical structure are determined with respect to each of the kinetic images using a reference image and the data of the determine result are attached to the kinetic images (Step S4). By the control part of a diagnostic console, the kinetic images are displayed on a display part and the position and name of the anatomical structure are displayed with respect to the image region determined to be abnormal on the basis of the attached data of the kinetic images (Step S6). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dynamic image processing system.

2. Description of the Related Art Conventionally, an apparatus for analyzing an X-ray image or the like and detecting an image region estimated as a lesion has been developed (see, for example, Patent Document 1). In such a detection device, a lesion having a density characteristic different from that of a normal tissue is detected in an X-ray image or the like, a display indicating the detected candidate region of the lesion is performed, and a doctor observes the X-ray image or the like It provides reference information when judging whether it is abnormal or normal.
JP-A-7-37061

  However, lung ventilation requires observation through the respiratory cycle, and normal or abnormal judgment cannot be made with only one image. Moreover, not only the local lesion part that causes a decrease in ventilation capacity, but also the lung area affected by the lesion part may be important for diagnosis. Therefore, it cannot be said that the conventional method of detecting and displaying only the lesioned part can provide sufficient diagnosis support for the ventilation ability.

  An object of the present invention is to provide information effective for diagnosis of lung ventilation ability.

According to the invention of claim 1,
An imaging means for capturing a dynamic image of the subject's chest and generating dynamic images at a plurality of time phases;
Using the dynamic images in the plurality of temporal phases, calculating the area change rate and / or signal change rate over time for each region obtained by dividing the lung field region included in each dynamic image into a plurality of regions, First determination means for determining normal or abnormal ventilation capacity for each region based on the calculated area change rate and / or signal change rate;
Second determination means for determining the position and name of the anatomical structure for the dynamic images in the plurality of temporal phases using a reference image in which the position and name of the anatomical structure in the lung are predetermined;
Display means for displaying at least one of the plurality of dynamic images;
In the displayed dynamic image, control means for displaying information on the position and name of the determined anatomical structure for the area determined to be abnormal,
A dynamic image processing system is provided.

According to invention of Claim 2,
Depending on the position and name of the anatomical structure defined at multiple classification levels, the reference image is created for each of multiple classification levels,
The dynamic image processing system according to claim 1, wherein the second determination unit determines a position and a name of an anatomical structure at each classification level using a reference image created for each of the plurality of classification levels. Is done.

According to invention of Claim 3,
The reference image is created for each attribute of the subject,
Input means for inputting information on the attributes of the subject of the dynamic shooting,
3. The dynamic image processing system according to claim 1, wherein the second determination unit uses a reference image having an attribute corresponding to the input information among reference images created for each attribute of the subject. The

According to invention of Claim 4,
The dynamic image processing system according to any one of claims 1 to 3, wherein the control unit displays index information indicating a region determined to be abnormal.

According to the invention of claim 5,
The dynamic image processing system according to any one of claims 1 to 4, wherein the control unit displays a region determined to be abnormal in a display form different from a region determined to be normal.

  According to the first aspect of the present invention, not only information on a region where there is a high possibility of abnormality in lung ventilation, but also information on the position and name of an anatomical structure that may be affected by the abnormality. Can be provided to doctors. Therefore, it is possible to provide information useful for diagnosis of lung ventilation ability to a doctor.

  According to the second aspect of the present invention, information on the position or name of the anatomical structure at each classification level can be provided to the doctor. Doctors can see from the viewpoint of each classification level.

  According to the third aspect of the present invention, the position and name of the anatomical structure can be determined using the reference image close to the feature of the subject, and the determination can be made with high accuracy.

  According to the fourth aspect of the present invention, the doctor can easily grasp the position of the area determined to be abnormal.

  According to the invention described in claim 5, the doctor can easily identify the area determined to be abnormal.

First, the configuration will be described.
FIG. 1 shows a dynamic image processing system 1 in the present embodiment.
As illustrated in FIG. 1, the dynamic image processing system 1 includes an imaging device 10, an imaging console 20, a diagnostic console 30, an image processing device 40, and a server 50. The constituent devices 10 to 50 are connected via a network N.

With reference to FIG. 2, the imaging device 10, the imaging console 20, and the diagnostic console 30 will be further described. The imaging apparatus 10, the imaging console 20, and the diagnostic console 30 are used when imaging an X-ray image of a subject.
As shown in FIG. 2, the imaging apparatus 10 includes an X-ray source 11, a detector 12, a reading unit 13, and a cycle detection unit 14. On the other hand, the imaging console 20 includes a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, and a communication unit 25. Similarly, the diagnostic console 30 includes a control unit 31, a storage unit 32, an operation unit 33, a display unit 34, and a communication unit 35.

First, the imaging device 10 will be described.
The imaging apparatus 10 irradiates the subject W with X-rays and reads an X-ray image from the detector 12. The photographing apparatus 10 can perform dynamic photographing. Dynamic imaging is an imaging method in which imaging is performed continuously to obtain dynamic images at a plurality of time phases. The dynamic image refers to a captured image obtained by dynamic imaging, and in this embodiment, the dynamic image is an X-ray image.

  The X-ray source 11 emits X-rays according to the control of the control unit 21 of the imaging console 20. Examples of controlled X-ray irradiation conditions include pulse rate, pulse width, pulse interval, irradiation start / end timing, X-ray tube current, X-ray tube voltage, filter value, and the like during continuous imaging in dynamic imaging. The pulse rate refers to the number of imaging per unit time, and the pulse width is the X-ray irradiation time per imaging. The pulse interval is the time from the start of X-ray irradiation in continuous imaging until the start of X-ray irradiation in the next imaging.

  The detector 12 is disposed at a position facing the X-ray source 11 with the subject W interposed therebetween. The detector 12 is an FPD (Flat Panel Detector) or the like in which X-ray detection sensors are arranged in a matrix. That is, X-rays are converted into electrical signals corresponding to the intensity and stored for each pixel (detection sensor), so that an X-ray image is recorded on the detector 12.

  The reading unit 13 performs processing for reading an X-ray image from the detector 12, and transmits the read X-ray image to the imaging console 20. The reading operation is controlled by the control unit 21. Image reading conditions to be controlled include a frame rate, a frame interval, a pixel size, an image size, and the like. The frame rate and the frame interval are the same as the pulse rate and the pulse interval.

The cycle detection unit 14 detects a cycle of the biological reaction for the imaging region of the subject W. For example, when the imaging region is a chest including a lung field, a respiratory cycle is detected by applying a respiratory monitor belt, a CCD camera, an optical camera, a spirometer, or the like. When the imaging region is the heart, the heartbeat cycle is detected using a heartbeat meter, an electrocardiograph or the like.
The cycle detection unit 14 outputs the detected cycle information to the control unit 21 of the imaging console 20.

Next, the imaging console 20 and the diagnostic console 30 will be described.
The imaging console 20 is used for an imaging operation of the engineer, and receives an input of imaging conditions and displays an X-ray image of the imaging apparatus 10 for the engineer's confirmation. The diagnostic console 30 is used for a doctor's operation, and displays an X-ray image transmitted from the imaging console 20 for a doctor's confirmation.

  The functions of each part of the diagnostic console 30 (the control unit 31, the storage unit 32, the operation unit 33, the display unit 34, and the communication unit 35) are the same as those of the imaging console 20 (the control unit 21, the storage unit 22, the operation unit 23, The display unit 24 and the communication unit 25) are basically the same. Therefore, here, each part of the imaging console 20 will be described as a representative, and description of each part of the diagnostic console 30 will be omitted.

The control unit 21 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like. The control unit 21 reads various programs stored in the storage unit 22 by the CPU, expands them in the RAM, performs various calculations in cooperation with the expanded programs, and centrally controls the operations of the respective units. Execute the process.
The control unit 21 has a timer function for measuring time using the CPU clock.

  The storage unit 22 is a memory such as a hard disk, and stores various programs used by the control unit 21 and parameters necessary for executing the programs. For example, the imaging conditions (such as X-ray irradiation conditions and X-ray image reading conditions) optimized for each imaging region are stored.

  The operation unit 23 includes a keyboard, a mouse, and the like, generates an operation signal according to these operations, and outputs the operation signal to the control unit 21. The operation unit 23 is one of input means for inputting patient information including information related to the attribute of the subject W.

The display unit 24 includes a display, and displays various operation screens, X-ray images obtained by imaging, and the like according to display control of the control unit 21.
The communication unit 25 includes a communication interface, and communicates with an external device connected to the network N.

Next, the image processing apparatus 40 and the server 50 will be described.
The image processing device 40 and the server 50 are used to provide an X-ray image obtained by imaging.
The image processing apparatus 40 will be described with reference to FIG.
The image processing apparatus 40 performs image processing on an X-ray image so that the image quality is easy for a doctor to observe. As shown in FIG. 3, the image processing apparatus 40 includes a control unit 41, an operation unit 42, a display unit 43, a storage unit 44, a communication unit 45, an image processing unit 46, and an image analysis unit 47.

  Since the basic functions of the control unit 41 to the communication unit 45 are the same as those of the control unit 21 to the communication unit 25 of the imaging console 20 described above, detailed description thereof is omitted here.

  The image processing unit 46 performs various image processing such as gradation conversion processing and frequency adjustment processing on the X-ray image. The image processing is performed according to the image processing conditions corresponding to the imaging region, depending on the type corresponding to the imaging region.

  The image analysis unit 47 analyzes the X-ray images at a plurality of time phases obtained by dynamic imaging of the chest in cooperation with the CPU and the program related to the determination process, and determines whether the ventilation ability is normal or abnormal. Further, the image analysis unit 47 determines the position and name of the anatomical structure for the X-ray image. A specific determination method will be described later.

  The server 50 includes a large-capacity memory, and stores and manages the X-ray image processed by the image processing apparatus 40 in this memory. The X-ray image stored in the server 50 is distributed in response to a request from the diagnostic console 30 and used for diagnosis.

Next, the operation will be described.
The dynamic image processing system 1 according to the present embodiment performs dynamic imaging of the chest, performs image analysis using the obtained dynamic images in a plurality of time phases, determines normal or abnormal ventilation capacity, and anatomically The position and name of the structure are determined, and the determination result is displayed.
FIG. 4 is a flowchart showing the flow of processing in the imaging device 10, the diagnostic console 30, and the image processing device 40 that mainly function at that time.

As shown in FIG. 4, first, dynamic imaging is performed by the imaging device 10 to generate dynamic images at a plurality of time phases (step S1).
At the time of imaging, the imaging engineer inputs patient information regarding the subject W, specifies an imaging region, and the like via the operation unit 23 of the imaging console 20. In addition to the subject W, that is, the patient's name, the patient information includes information indicating patient attributes such as age, sex, weight, and height. In addition, although the example of the operation part 23 was given as an input means of patient information, it is good also as acquiring patient information managed by the diagnostic console 30, the server 50, etc. In this case, the communication part 25 is input means. Function as.

In the imaging console 20, an imaging condition corresponding to an imaging region designated by the control unit 21 is read from the storage unit 22 and set as an X-ray irradiation condition in the X-ray source 11 of the imaging apparatus 10 and an image reading condition in the reading unit 13. To do. In the following description, it is assumed that the imaging region of “lung (ventilation)” is designated by the imaging technician. When the lungs are imaged to see the ventilation capacity, the respiratory cycle is about 0.3 times / second on average, so in order to perform dynamic imaging for at least one respiratory phase in consideration of this, for example, the following imaging conditions Is set.
Frame rate (pulse rate): 3 frames / second (that is, 3 shots per second)
Pixel size: 400μm
Image size: 40cm x 30cm
Tube voltage: 120 kV
Tube current: 50 mA
Shooting timing: Every frame interval from the timing of the conversion point from inspiration to expiration (shooting start timing)

  The control unit 21 corrects conditions such as a frame rate based on the information on the respiratory cycle detected by the cycle detection unit 14. For example, based on the detected respiratory cycle, the control unit 21 calculates and resets the frame rate so that one cycle is shot with a predetermined number of frames (for example, 10 frames). In the above example of the frame rate condition, when the number of respiratory cycles detected by the cycle detection unit 14 is 0.25 times / second, the frame rate is corrected to 2.5 frames / second.

  After setting the imaging conditions, the control unit 21 determines whether or not the imaging start timing, that is, the timing at which the dynamics of one respiratory cycle starts (for example, conversion from inspiration to expiration) based on the respiratory cycle information detected by the cycle detection unit 14. Point). At the imaging start timing, the control unit 21 controls the X-ray source 11 and the reading unit 13 to start dynamic imaging. In addition, the control unit 21 passes the shooting time required from the start to the end of shooting in accordance with the start of dynamic shooting.

  In the imaging apparatus 10, X-rays are emitted from the X-ray source 11 at a predetermined pulse rate in accordance with the set X-ray irradiation conditions. Similarly, the reading unit 13 performs X-ray image reading processing from the detector 12 at a predetermined frame rate in accordance with the set image reading conditions. The control unit 21 synchronizes the X-ray irradiation operation and the image reading operation. Thereby, dynamic images in a plurality of time phases are generated and output to the imaging console 20.

  In the imaging console 20, a dynamic image of each time phase obtained by dynamic imaging by display control of the control unit 21 is displayed on the display unit 24. This is because the photographer confirms the image quality and the like. When an approval operation is performed by the imaging engineer via the operation unit 23, the control unit 21 performs diagnosis by attaching an ID for identifying a series of imaging, patient information, and imaging time information to the dynamic image of each time phase. To the console 30. In the same manner, the diagnostic console 30 also displays a confirmation display (step S2). When an approval operation is performed, a dynamic image of each time phase is transmitted to the image processing device 40.

  In the image processing apparatus 40, the dynamic image of each time phase is subjected to image processing according to the imaging region of the lung (ventilation) by the image processing unit 46, and then the normality or abnormality of the ventilation ability is determined by the image analysis unit 47. Is performed (step S3). The determination of normal or abnormal ventilation capacity is performed by calculating the area change rate and / or signal change rate of the lung field region.

Processing related to normality or abnormality determination will be described with reference to FIG.
As shown in FIG. 5, the image analysis unit 47 sets an arbitrary dynamic image among the dynamic images of each time phase as a reference image (step S31). Next, the image analysis unit 47 detects a lung field region from the reference image, and divides it into a plurality of small regions as indicated by dotted lines in FIG. 6 in a substantially rectangular region circumscribing the detected lung field region (step S32). . The small area to be divided may be 0.4 to 4 cm square, for example.

  Note that the lung field region detection method may be any method. For example, a threshold value is obtained by discriminant analysis from a histogram of signal values of the reference image, and a region having a signal higher than the threshold value is primarily detected as a lung field region. Next, edge detection is performed in the vicinity of the boundary of the first detected region, and a point in the edge in the small region near the boundary is extracted along the boundary, so that the boundary of the lung field region can be detected.

  Next, regions corresponding to the divided regions of the reference image in the dynamic images of other time phases are obtained by local matching (step S33). Specifically, a dynamic image in which the reference image and the time phase are adjacent (that is, the closest time phase) is divided into, for example, an area twice as large as the reference image. Then, the corresponding divided area of the reference image is moved in the divided area having the double size, the matching degree is calculated for each movement, and the position where the matching degree is maximized is obtained. The degree of matching refers to the degree of image matching, and can be obtained by the least square method or cross-correlation. By repeating this process between the dynamic images adjacent in time phase, it is possible to determine which region of the dynamic image in another time phase corresponds to each divided region of the reference image.

  Next, the image analysis unit 47 calculates an area change rate and / or a signal change rate for each corresponding region (step S34). First, the image analysis unit 47 generates a region having a vertex at the center point of the divided region of the reference image. A region indicated by a solid line in FIG. 6 is a newly generated region. And the area change rate with progress of time is calculated | required about the area of the newly produced | generated area | region. The area is obtained from the number of pixels in the region, and the area change rate is obtained between dynamic images having adjacent time phases. In other words, the area ratio determined by the center point of the four areas that correspond to each other based on the reference image in the two dynamic images adjacent in time phase is sequentially calculated between the adjacent dynamic images as the area change rate. .

  On the other hand, for each newly generated area, the signal value of each pixel in the area is divided by the number of pixels to obtain an average signal value. Then, the rate of change of the average signal value with the passage of time is obtained as the signal rate of change. That is, the ratio of the average signal value in the region determined by the center point of the four regions that correspond to each other based on the reference image in the two dynamic images whose temporal phases are adjacent to each other is sequentially used as the signal change rate between the adjacent dynamic images. calculate. Instead of the average signal value, the sum of the signal values of each pixel in the region may be calculated, and the rate of change of the sum of the signal values over time may be adopted as the signal rate of change.

  After calculating the area change rate and / or signal change rate, the image analysis unit 47 determines whether the ventilation capacity is normal or abnormal for each region based on the area change rate and / or signal change rate obtained for each corresponding region. Determination is made (step S35). Here, in order to determine the abnormality of the ventilation ability from various aspects, the determination is performed from the viewpoint of a change with time and a change in the vicinity of each divided region. The following determination may be performed using only one of the area change rate and the signal change rate, or may be performed using both.

  When judging from the viewpoint of changes due to time, the lung field is divided into left and right and up and down, and the area change rate and / or signal change rate calculated in the dynamic image of each time phase is divided into the left and right and top and bottom of the lung field over time. See how the area and signal values change. The vertical direction of the lung field is the sub-scanning direction referred to in the dynamic image in FIG. 6, and the horizontal direction is the main scanning direction referred to in the dynamic image in FIG.

  When viewing the change in the left and right, the average value of the area change rate and / or the signal change rate of the region where the position in the sub-scanning direction is substantially the same in the lung field region is obtained in each of the left and right lung field regions. The lung field repeatedly expands and contracts in the vertical direction by breathing, and the extent of the expansion and contraction is almost the same in the left and right lung fields. Generally, it is almost the same in the field. Therefore, if the difference between the average values obtained in the left and right lung field regions is greater than or equal to the threshold value, the area change rate and / or signal change rate is significantly different between the left and right, and abnormal ventilation may be considered. Is determined to be abnormal. When the difference between the average values is below the threshold value, it is determined as normal. This determination is sequentially performed in the sub-scanning direction of the lung field region. The threshold value may be set by obtaining in advance a value that should be determined empirically or experimentally as abnormal.

In the case of looking at the vertical change, the average value of the area change rate and / or the signal change rate of the region in the lung field region where the position in the sub-scanning direction is substantially the same is obtained. This is sequentially obtained in the sub-scanning direction of the lung field region. If the relationship between the average values calculated in each sub-scanning direction does not satisfy the following conditions 1 and 2, it is determined as abnormal. Conversely, if conditions 1 and 2 are satisfied, it is determined as normal.
Condition 1: The smaller the upper lung field (lung tip), the smaller. Condition 2: The higher the lung field (lung tip), the slower the start of the mean value change. It expands, and the exhalation causes the lower lung field to contract and return to its original size. In other words, if the ventilation ability is normal, the upper lung field is less stretched and contracted than the lower lung field, and the timing to start stretching and contracting is slower than the lower lung field. If the above conditions 1 and 2 indicating the characteristics in the vertical direction are not satisfied, an abnormality in ventilation ability is considered.

  On the other hand, when judging from the viewpoint of the change in the vicinity of each divided region, the difference in area change rate and / or signal change rate is obtained between regions in which the sub-scanning direction is substantially the same in the lung field region, and this difference is determined in advance. Compare with the threshold value. Usually, the lower lung field expands by inspiration, and the lower lung field contracts by exhalation and returns to the original size. That is, expansion and contraction are repeated in the vertical direction of the lung field, and the change in the horizontal direction of the lung field is not as great as in the vertical direction. Therefore, when the difference between the obtained area change rate and / or signal change rate is larger than the threshold value, it is estimated that the area change rate and / or signal change rate in the main scanning direction is abnormally large, and the region is regarded as abnormal. judge. If it falls below the threshold, the area is determined to be normal.

  In addition, it is good also as calculating | requiring the area change rate and / or signal change rate with respect to a reference | standard image, and further determining the normality or abnormality of ventilation capacity similarly to the above. The calculation method of the area change rate and the signal change rate with respect to the reference image is the same as the above-described method, although the target image is different in that it is obtained between the reference image and the dynamic image of another time phase. The determination may be performed in the same manner as described above using the area change rate and / or signal change rate with respect to the obtained reference image. As a result, in addition to the area and signal value change at the adjacent time phase, normal or abnormal judgment can be performed from the aspect of change from the reference time phase, and multi-faceted judgment is possible. It becomes.

Next, the image analysis unit 47 displays information on the result of determination of normality or abnormality of the ventilation ability, and information on the area change rate and / or signal change rate of the image portion when it is determined to be abnormal, The image is attached (step S36).
As described above, when the determination of normality or abnormality of the ventilation ability is completed, the image analysis unit 47 performs the process of determining the position and name of the anatomical structure for the dynamic image of each time phase as shown in FIG. Step S4).

With reference to FIG. 7, the process for determining the position and name of the anatomical structure will be described.
As shown in FIG. 7, first, the image analysis unit 47 analyzes the dynamic image at each time phase and determines the respiratory phase (step S41).

FIG. 8 is a diagram showing dynamic images of a plurality of time phases T (T = t _{0 to} t ₆ ) that are dynamic images in one respiratory cycle. As shown in FIG. 8, since the lung air is exhausted during expiration, the lung field is contracted. When inhaling, air flows into the lungs, so the lung field is stretched. Therefore, the image analysis unit 47 calculates the area (number of pixels) of the lung field region of the dynamic image related to each time phase T, and the dynamics from the time phase t ₀ where the area is the maximum to the time phase t ₃ where the area is the minimum. an image determining expiratory phase, the dynamic image of the area from the minimum time phase t ₃ to the maximum time phase t ₆ as the intake phase. In addition, it is good also as specifying a respiratory phase from the height of a diaphragm. The place where the height of the diaphragm is maximum is the maximum expiratory position, and the place where the height is minimum is the maximum inspiratory position.

  Next, the image analysis unit 47 determines a reference image to be used for a matching process described later from among the plurality of reference images based on the patient information attached to the dynamic image (step S42). The reference image refers to an image in which the name and position of the anatomical structure are determined in advance for the lung field.

  The position and name of the anatomical structure are determined at a plurality of classification levels, and a reference image is created and stored for each classification level. As an example, reference images created according to three classification levels 1 to 3 are shown in FIGS. 9A, 9B, and 9C. As shown in FIGS. 9A, 9B, and 9C, in the reference image, the lung field region is classified into a plurality of anatomical structures, and the positions and names of the anatomical structures are determined. In FIG. 9A, FIG. 9B, and FIG. 9C, what is shown in the image area | region of each anatomical structure is the name of the anatomical structure.

  Classification level 1 is the largest classification among the three classification levels, and the name and position of the anatomical structure are determined. Classification level 2 is a further classification of the anatomical structure of classification level 1. is there. Classification level 3 defines an anatomical structure in the bronchial unit of the lung, and is a finer classification than classification levels 1 and 2. That is, as shown in FIG. 9A, FIG. 9B, and FIG. 9C, the name of the anatomical structure is the reference image of the classification level 1 if the classification level is different even if the areas are in the same position (area indicated by oblique lines). Is the right middle lobe region, which differs from the right fourth region in the reference image of the classification level 2 and from the right first bronchus region in the reference image of the classification level 3.

A plurality of the reference images are created according to the time phase of one respiratory cycle. That is, a plurality of reference images relating to each time phase are stored in the storage unit 44 as one set.
Furthermore, the reference image is created according to the patient's attribute. Patient attributes refer to physical attributes such as patient gender, age, weight, and height. For example, reference images are created for each age group from the 20s to 60s and for each gender, and stored in the storage unit 44.

  Therefore, in step S42, the attribute of the patient who has become the subject W is determined based on the patient information attached to the dynamic image, and the reference image corresponding to the determined attribute among the reference images stored in the storage unit 44. Is determined and read.

  Next, since the reference image is created according to a plurality of time phases as described above, the image analysis unit 47 determines the respiratory phase of the dynamic image and the respiratory phase of the reference image based on the respiratory phase determined in step S41. Are associated with the dynamic image of each time phase and the reference image of each time phase (step S43). When the association is completed, the image analysis unit 47 performs a matching process for substantially matching the associated dynamic image and the reference image (step S44).

The matching process will be described with reference to FIG.
As shown in FIG. 10, the image analysis unit 47 corrects the signal value for the dynamic image of each time phase (step S441). This is because the X-ray image may cause variations in signal values due to differences in X-ray irradiation conditions and the like, and needs to be matched. Specifically, the maximum signal value and the minimum signal value are obtained from the histogram of the signal value of the dynamic image, and the signal value is converted so as to coincide with a predetermined reference signal value.
Similarly, the image analysis unit 47 corrects the signal value for the reference image (step S442), and matches the X-ray image and the reference image to the same reference signal value.

  When the correction is completed, the image analysis unit 47 performs initial position alignment by performing a process of repeating rotation and translation (affine transformation or the like) on the dynamic image and the reference image corresponding to the respiratory phase (step S445). This is because the positions of the images of the subject W included in the X-ray image and the reference image are often shifted, so that the positions are matched as much as possible before the subsequent processing. Initial alignment is performed for all combinations of corresponding dynamic images and reference images.

  Next, the image analysis unit 47 divides the dynamic image subjected to the initial alignment into a plurality of small regions (step S443). Then, the image analysis unit 47 associates each divided region of the dynamic image with the image region of the reference image (step S445). The association method is the same as the local matching method in step S33 of FIG. That is, the reference image is divided into regions each having a size approximately twice as large as the divided region of the X-ray image. Among the divided areas of the reference image, the divided area of the dynamic image is moved, and the area having the highest matching degree is associated with the divided area of the dynamic image.

  Next, nonlinear warping processing is performed on the dynamic image so that the divided region of the associated dynamic image and the region of the reference image substantially match (step S446). In the nonlinear warping process, a shift value from the center position of each divided area of the dynamic image to the center position of the associated reference image area is obtained, and a two-dimensional 10th order polynomial is used using the shift value for each divided area. By performing approximation processing, shift values for all pixels of the reference image are obtained for all pixels of the dynamic image. Then, all the pixels of the dynamic image are shifted by the calculated shift value.

The non-linear warping process will be described with reference to FIG. FIG. 11 shows a dynamic image g1 and a reference image r1 corresponding to the respiratory phase.
A dynamic image g2 is obtained by dividing the dynamic image g1 into a plurality of regions. The reference image r2 associates the divided area of the dynamic image g2 with the reference image r2. The dynamic image g2 is subjected to nonlinear warping processing so that each divided region and the region associated with the reference image r2 substantially coincide with each other. The image after the nonlinear warping process is the dynamic image g3. As can be seen from FIG. 11, the image portion of the subject W in the dynamic image g3 and the reference image r2 substantially coincide.

The above matching process is performed for a plurality of classification levels. That is, matching processing is performed using the reference images of the respective classification levels. When the matching process is completed, the process proceeds to step S45 in FIG.
In step S45, the position and name of the anatomical structure are determined in the dynamic image substantially matched with the corresponding reference image as a result of the matching process for each classification level (step S45). That is, when matching processing with a reference image is performed, an image region that matches an anatomical structure whose name and position are determined in the reference image is determined to be an anatomical structure of that name. For example, as a result of matching with the reference image of the classification level 1, the name and position of the anatomical structure related to the classification level 1 can be determined in the lung field region of the dynamic image g1 as shown in FIG.

  Next, the image analysis unit 47 determines the anatomical structure to which the image region determined to be abnormal in the dynamic image of each time phase based on the determination result of the position and name of the anatomical structure and the determination information of normal or abnormal The position and name of the are determined. Also in this case, the determination is made at each classification level (step S46). For example, if the hatched portion shown in FIGS. 9A, 9B, and 9C is determined to be abnormal, the name of the anatomical structure to which the determined abnormal portion belongs is the right middle lobe region, the classification level at classification level 1 2 is determined as the right fourth region, and classification level 3 is determined as the right right bronchus region.

As a determination result, the image analysis unit 47 determines the position and name of the anatomical structure determined in the dynamic image of each time phase, and if there is an image area determined to be abnormal, the anatomical to which this image area belongs. Information on the position and name of the structure is attached to the dynamic image of each time phase (step S47).
Thereafter, the dynamic image of each time phase accompanied with the information of the determination result is transmitted to the server 50 via the communication unit 44.

  The server 50 creates a database of dynamic images of each time phase together with the accompanying information and stores it in a memory. If there is a request from the diagnostic console 30, the server 50 transmits a dynamic image group of the patient related to the request.

  As shown in FIG. 4, the diagnostic console 30 displays the dynamic image of each time phase acquired from the server 50 on the display unit 34 by the display control of the control unit 31 (step S5). At this time, the control unit 31 continuously switches each dynamic image according to the time phase and displays it as a moving image. The doctor can grasp the dynamic change.

  Next, the control unit 31 displays the determination result of the ventilation ability and the determination result of the anatomical structure based on the incidental information of the displayed dynamic image (step S6). Specifically, the index information indicating the image area determined to be abnormal is displayed as the determination result of the ventilation capacity, and the display form is displayed so as to be distinguished from the normal tissue. In addition, the area change rate and / or signal change rate information is displayed for the image region determined to be abnormal. On the other hand, as the determination result of the anatomical structure, the name of the anatomical structure to which the image region determined to be abnormal belongs is displayed for each classification level.

FIG. 13A, FIG. 13B, and FIG. 13C show examples of the display screen.
As shown in FIG. 13A, the control unit 31 displays index information a1 indicating the position of the image region g11 determined to be abnormal in the dynamic image g1, and a color different from that of the image region determined to be normal. The display form is displayed so as to be identifiable as different. Further, the boundary line g12 of the anatomical structure (classification level 1) to which the image region determined to be abnormal belongs is displayed to indicate the position thereof, and the index information a2 indicating the name of the anatomical structure is displayed.

FIG. 13B shows a display example in the case of classification level 2, and FIG. In this case, the boundary line g12 of the anatomical structure to which the image region g11 determined to be abnormal belongs to the classification level 2 or 3. In addition, the display content of the index information a2 is changed to a name corresponding to the classification level 2 or 3.
As described above, the display screens of the respective classification levels may be automatically switched and displayed, or may be switched and displayed only when a switching operation is performed.

FIG. 14 is a display screen example of the area change rate calculated for the image area determined to be abnormal.
For example, when there are two image regions determined to be abnormal, the control unit 31 represents these as abnormal regions A and B as shown in FIG. 14, and the area change rates calculated respectively are time phases (or respiratory phases). A graph is displayed accordingly. By graphing the area change rate in one breathing cycle, it is possible to grasp the tendency of abnormalities such as abnormalities in abnormal area A during breathing and abnormal areas B occurring at regular intervals. It becomes possible.

At this time, a breathing phase graph may be displayed as reference information for grasping the phase of expiration and inspiration. As a graph of the respiratory phase, for example, as shown in FIG. 14, the diaphragm height may be obtained from the dynamic image of each time phase and plotted by the time phase, or the measurement value obtained by a spirometer or the like is plotted. It may be a spirogram.
Although only the display example of the area change rate is shown, the signal change rate may be displayed similarly.

  As described above, according to the present embodiment, the imaging device 10 performs dynamic imaging of the chest of the subject W and generates dynamic images in a plurality of time phases. The image analysis unit 47 of the image processing device 40 calculates the area change rate and / or the signal change rate for each region obtained by dividing the lung field region included in each dynamic image into a plurality of regions using each dynamic image, Based on the area change rate and / or signal change rate, a determination is made as to whether the ventilation capacity is normal or abnormal. Further, the position and name of the anatomical structure are determined for each dynamic image using the reference image, and information on the determination result is attached to the dynamic image. The control unit 31 of the diagnostic console 30 displays the dynamic image on the display unit 34, and displays the position and name of the anatomical structure for the image region determined to be abnormal based on the incidental information of the dynamic image. Let

  This makes it possible to provide doctors with information that is effective in diagnosing the ventilation ability of the lungs. That is, it is possible to provide not only the determination information of the abnormal part of the ventilation ability but also the information of the position and name of the anatomical structure that the abnormal part may influence.

  Reference images are created according to the classification level of the anatomical structure, and the position and name of the anatomical structure are determined and displayed for each classification level, so the doctor grasps the anatomical structure at each classification level. can do.

  Moreover, since the reference image is created for each patient attribute and the position or name of the anatomical structure is determined using the reference image having the attribute corresponding to the patient information, a highly accurate determination can be performed.

  Further, when displaying an image area determined to be abnormal, index information indicating the image area is displayed. Furthermore, since the display is performed in a display form different from the area determined to be normal, the doctor can easily grasp the image area determined to be abnormal.

The above description is a preferred example of the present invention, and the present invention is not limited to this.
For example, the reference image may be prepared and prepared for each breathing method of normal breathing and deep breathing.

  Further, the determination of normal or abnormal ventilation ability may be made by using only a dynamic image of a specified time phase instead of using a dynamic image of all time phases. For example, if the doctor determines that there is an abnormality in the conversion period from exhalation to inspiration, and only wants to make a determination in the conversion period, the time phase for determination in the diagnostic console 30 is the time phase for determining from exhalation to inspiration. Specify the conversion period. In response to this designation operation, the image analysis unit 47 of the image processing apparatus 40 may perform normality or abnormality determination processing using only the dynamic image relating to the time phase around the conversion period from expiration to inspiration. This reduces the number of images to be processed and improves the processing efficiency.

  In the above embodiment, the chest is dynamically photographed to determine normality or abnormality of the lung ventilation and the position and name of the anatomical structure of the lung field are described. It may be applied to other parts. That is, by taking a dynamic image of the heart, and using the obtained dynamic image, the area change rate and / or signal change rate with the passage of time of the heart is calculated in the same manner as described above. The normal or abnormal cardiac function of the heart is determined from the signal change rate. Normal or abnormal criteria are determined according to the heart. Further, the position and name of the anatomical structure are determined with respect to the dynamic image taken using the reference image in which the position and name of the anatomical structure such as the right atrium and the left ventricle are determined in advance for the heart. According to this, it becomes possible to provide information to the doctor regarding the cardiac function.

  Moreover, although the structure which displays a determination result in the diagnostic console 30 was demonstrated, it is good also as displaying in the imaging | photography console 20 or another apparatus (PC etc. used for a diagnosis). Further, the configuration in which the image processing apparatus 40 for performing image analysis is provided and the determination is performed in the image processing apparatus 40 has been described. However, in the diagnostic console 30 and other apparatuses, the determination of normality or abnormality of the ventilation ability, the anatomical structure It is also possible to install a program for performing the determination and perform the calculation.

  Further, as a computer-readable medium for storing the program related to the above-described processing, a portable type such as a DVD can be applied in addition to a memory such as a ROM. Also, a carrier wave can be used as a medium for providing female program data via a network.

It is a figure which shows the structure of the dynamic image processing system in this embodiment. It is a figure which shows the functional structure of the imaging device of FIG. 1, an imaging console, and a diagnostic console. It is a figure which shows the functional structure of the image processing apparatus of FIG. It is a flowchart which shows the flow of a process of a dynamic image processing system. It is a flowchart which shows the flow of a process at the time of determining the normality or abnormality of ventilation capacity in an image processing apparatus. It is a figure explaining the method of matching of the area | region by local matching. It is a flowchart which shows the flow of a process at the time of determining an anatomical structure in an image processing apparatus. It is a figure which shows the example of the dynamic image in a some time phase. It is a figure which shows the reference image example of the classification level 1. FIG. It is a figure which shows the reference image example of the classification level 2. FIG. It is a figure which shows the reference image example of the classification level 3. FIG. It is a flowchart which shows the flow of the matching process in an image processing apparatus. It is a figure which shows the example of the dynamic image and reference image which are matched. It is a figure which shows the example of the dynamic image from which the position and name of the anatomical structure were discriminate | determined by the matching process. It is a figure which shows the example of a display which showed the image area determined to be abnormal by the anatomical structure of the classification level 1. It is a figure which shows the example of a display which showed the image area | region determined to be abnormal by the anatomical structure of the classification level 2. FIG. It is a figure which shows the example of a display which showed the image area determined to be abnormal by the anatomical structure of the classification level 3. It is a figure which shows the example of a display of the area change rate of the image area | region determined to be abnormal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dynamic image processing system 10 Imaging device 11 X-ray source 12 Detector 13 Reading part 14 Cycle detection part 20 Imaging console 21 Control part 30 Diagnosis console 31 Control part 34 Display part 40 Image processing apparatus 46 Image processing part 47 Image analysis Part

Claims (5)

An imaging means for capturing a dynamic image of the subject's chest and generating dynamic images at a plurality of time phases;
Using the dynamic images in the plurality of temporal phases, calculating the area change rate and / or signal change rate over time for each region obtained by dividing the lung field region included in each dynamic image into a plurality of regions, First determination means for determining normal or abnormal ventilation capacity for each region based on the calculated area change rate and / or signal change rate;
Second determination means for determining the position and name of the anatomical structure for the dynamic images in the plurality of temporal phases using a reference image in which the position and name of the anatomical structure in the lung are predetermined;
Display means for displaying at least one of the plurality of dynamic images;
In the displayed dynamic image, control means for displaying information on the position and name of the determined anatomical structure for the area determined to be abnormal,
A dynamic image processing system comprising: Depending on the position and name of the anatomical structure defined at multiple classification levels, the reference image is created for each of multiple classification levels,
The dynamic image processing system according to claim 1, wherein the second determination unit determines a position and a name of an anatomical structure at each classification level using a reference image created for each of the plurality of classification levels. The reference image is created for each attribute of the subject,
Input means for inputting information on the attributes of the subject of the dynamic shooting,
The dynamic image processing system according to claim 1, wherein the second determination unit uses a reference image having an attribute corresponding to the input information among reference images created for each attribute of the subject.   The dynamic image processing system according to claim 1, wherein the control unit displays index information indicating a region determined to be abnormal.   The dynamic image processing system according to any one of claims 1 to 4, wherein the control unit displays a region determined to be abnormal in a display form different from that of a region determined to be normal.

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