JP2013102850A - Medical imaging system, medical image processing apparatus, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to accurately determine the presence or absence of the body motion of a subject at the photographing in the medical image of a still image.SOLUTION: In the medical imaging system, the controller of the console for photographing extracts a subject region from the medical image that is the still image acquired by taking an image of the subject, and extracts the local domain where the high spatial frequency component by an edge is not included from the subject region. In addition, the high spatial frequency component is extracted from the extracted local domain, the presence or absence of the body motion of the subject at the photographing is judged based on the high spatial frequency component that has been extracted, and a judged result is output by an output means.

Description

  The present invention relates to a medical image photographing system, a medical image processing apparatus, and a program.

  In recent years, a digital medical image of a still image is generated by photographing a region to be diagnosed as a subject, and image diagnosis is performed based on the generated medical image.

  If there is a body motion of a subject at the time of taking a medical image, the subject is blurred in the medical image, and a motion artifact is generated in which the human body structure is slightly blurred and imaged. Since an image in which motion artifact has occurred is inappropriate for diagnosis, a medical image in which motion artifact has occurred must be re-photographed.

  Therefore, for example, in Patent Document 1, by determining the presence or absence of body movement of a subject at the time of shooting in a medical image of a still image, it is possible to prevent a medical image in which a motion artifact has occurred from being used for diagnosis in advance. Techniques for improving the efficiency of the are described. In Patent Document 1, a high spatial frequency component of a medical image is extracted, and the presence or absence of body movement is determined based on the extracted high spatial frequency component.

Japanese Patent No. 4539186

  By the way, in a medical image obtained by photographing the front of the chest with a lung field as a subject, motion artifacts may occur due to body movement due to breathing during radiation exposure during imaging. In this case, the ribs of the subject are imaged while still, and motion artifacts occur in blood vessels in the lung field of the subject.

  In such a medical image, in order to determine the presence or absence of body movement, it is necessary to extract a high spatial frequency component of a blood vessel region in a lung field where a motion artifact has occurred. At this time, if the edge of the rib is included in the region from which the high spatial frequency component is extracted, the edge portion includes a large amount of the high spatial frequency component. Therefore, the presence / absence of body movement is correctly determined based on the extracted high spatial frequency. There was a problem that I could not.

  An object of the present invention is to make it possible to accurately determine the presence or absence of body motion of a subject at the time of photographing in a medical image of a still image.

In order to solve the above-described problem, a medical image photographing system according to claim 1 is provided.
Image generating means for capturing a subject and generating a medical image as a still image;
A region extracting means for extracting a subject region from the medical image and extracting a local region not including an edge from the subject region;
A body motion determination unit that extracts a high spatial frequency component from the local region extracted by the region extraction unit, and determines presence / absence of body motion of the subject at the time of photographing based on the extracted high spatial frequency component;
Control means for causing the output means to output the determination result by the body movement determining means;
Is provided.

The invention according to claim 2 is the invention according to claim 1,
The area extracting means divides the subject area into a plurality of small areas, and extracts a plurality of local areas not including an edge from the plurality of small areas,
The body motion determining unit extracts a high spatial frequency component from each of the plurality of local regions extracted by the region extracting unit, and based on the high spatial frequency component extracted from the plurality of local regions, the subject at the time of photographing The presence or absence of body movement is determined.

The invention according to claim 3 is the invention according to claim 1 or 2,
The body movement determination unit extracts high spatial frequency components in a plurality of directions, and determines presence or absence of body movement of the subject at the time of photographing based on the extracted high spatial frequency components in the plurality of directions.

The invention according to claim 4 is the invention according to any one of claims 1 to 3,
The output means is a display means for displaying and outputting the medical image generated by the image generation means;
The control means, when it is determined that there is a body movement by the body movement determination means, based on the position information of the local area extracted by the area extraction means and the high frequency component extracted from the local area An area to be enlarged and displayed is determined from the medical image, and the determined area is enlarged and displayed on the display means.

The medical image processing apparatus of the invention according to claim 5 is:
A region extracting means for extracting a subject region from a medical image that is a still image acquired by photographing a subject, and extracting a local region not including a high spatial frequency component due to an edge from the subject region;
A body motion determination unit that extracts a high spatial frequency component from the local region extracted by the region extraction unit, and determines presence / absence of body motion of the subject at the time of photographing based on the extracted high spatial frequency component;
Control means for causing the output means to output the determination result by the body movement determining means;
Is provided.

The program of the invention described in claim 6 is:
Computer
A region extracting means for extracting a subject region from a medical image that is a still image acquired by photographing a subject and extracting a local region not including a high spatial frequency component due to an edge from the subject region;
A body motion determination unit that extracts a high spatial frequency component from the local region extracted by the region extraction unit and determines the presence or absence of body motion of the subject based on the extracted high spatial frequency component;
Control means for causing the output means to output the determination result by the body movement determining means;
To function as.

  According to the present invention, it is possible to accurately determine the presence or absence of body motion of a subject at the time of shooting in a medical image of a still image.

1 is a diagram illustrating an overall configuration of a medical image photographing system according to an embodiment. It is a block diagram which shows the functional structure of the imaging | photography console. It is a flowchart which shows the imaging | photography control processing performed by the control part of an imaging | photography console. It is a flowchart which shows the body movement determination process performed in step S8 of FIG. It is a figure which shows typically the response of the spatial frequency in a still image. It is a figure which shows typically the response of the spatial frequency in the still image (body motion image) with a body motion in a horizontal direction. It is a figure which shows typically the response of the spatial frequency in the image containing the edge of a horizontal direction. It is a figure which shows the relationship between the vertical spatial frequency and the response in the image containing a horizontal edge and the image which does not contain an edge. It is a figure which shows an example of the lung field area | region extracted from the medical image. It is a figure for demonstrating the zone | band which calculates the maximum value or integral value of a response. It is a figure which shows an example of the local area | region which does not contain the edge extracted in step S103 of FIG. It is a figure for demonstrating the zone | band used as the calculation object of the parameter | index of the response of the high spatial frequency component of a vertical direction and a horizontal direction. It is a figure for demonstrating the band used as the calculation object of the parameter | index of the response of the high spatial frequency component of the diagonal direction. It is a figure for demonstrating the calculation method of a body movement feature-value. It is a figure which shows the determination process of the expansion area | region enlargedly displayed on a body movement warning screen (1st step). It is a figure which shows the determination process of the expansion area enlargedly displayed on a body movement warning screen (2nd step). It is a figure which shows the determination process of the expansion area | region enlargedly displayed on a body movement warning screen (3rd step). It is a figure which shows an example of a body movement warning screen.

  Hereinafter, embodiments of a medical image photographing system according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following illustrated examples.

(Configuration of medical imaging system)
First, the configuration of the medical image photographing system 100 in the present embodiment will be described.
FIG. 1 is a diagram showing an example of the overall configuration of a medical image photographing system 100 according to an embodiment of the present invention. The medical imaging system 100 is a system that shoots a still image of a subject by irradiating a subject (that is, an imaging region of the patient) that is a part of the patient's body. FIG. 1 shows a case where the medical image photographing system 100 is constructed in the photographing room R1.

  In the photographing room R1, for example, a bucky device 1 for standing position photographing, a bucky device 2 for standing position photographing, a radiation source 3, a photographing console 5, an operation console 6, and an access point AP are provided. Is provided. The photographing room R1 is provided with a front room Ra and a photographing room Rb, and the front room Ra is provided with a photographing console 5 and a console 6 to prevent exposure of an operator such as a photographing engineer. Yes.

Hereinafter, each device in the photographing room R1 will be described.
The bucky device 1 is a device for holding an FPD (Flat Panel Detector) 9 and performing shooting when shooting in a standing position. The bucky device 1 includes a holding portion 12a for holding the FPD 9 and a connector 12b for connecting a connector of the FPD 9 attached to the holding portion 12a. The connector 12b transmits / receives data to / from the FPD 9 attached to the holding unit 12a and supplies power to the FPD 9. The bucky device 1 also has an interface for transmitting / receiving data to / from an external device such as the imaging console 5 via the access point AP via a communication cable, and for moving the holding unit 12a vertically or horizontally. A foot switch is provided.

  The bucky device 2 is a device for holding the FPD 9 when shooting in the supine position. The bucky device 2 includes a holding portion 22a for holding the FPD 9 and a connector 22b for connecting a connector of the FPD 9 attached to the holding portion 22a. The connector 22b transmits / receives data to / from the FPD 9 attached to the holding unit 22a and supplies power to the FPD 9. The bucky device 2 also includes an interface for transmitting / receiving data to / from an external device such as the imaging console 5 via a communication cable via an access point AP, and a subject table 26 for placing a subject.

  The radiation source 3 is suspended from the ceiling of the imaging room R1, for example, and is activated based on an instruction from the imaging console 5 at the time of imaging, and is adjusted to a predetermined position and orientation by a driving mechanism (not shown). It has become. Then, by changing the irradiation direction of radiation, radiation (X-rays) can be irradiated to the FPD 9 mounted on the standing-side bucky device 1 or the lying-down bucky device 2. . Further, the radiation source 3 irradiates the radiation once in accordance with the radiation irradiation instruction from the console 6 and takes a still image.

  The imaging console 5 is a medical image processing apparatus for controlling imaging by controlling the radiation source 3 and the FPD 9 and performing image processing on a medical image generated by imaging and displaying it for confirmation. The imaging console 5 is connected to a HIS / RIS (Hospital Information System / Radiology Information System) 7, a diagnostic console 8, a server device 10, etc. via a LAN (Local Area Network), and is transmitted from the HIS / RIS 7. Based on the imaging order information, the radiation source 3 and the FPD 9 are controlled to perform imaging.

  FIG. 2 shows a configuration example of a main part of the imaging console 5. As shown in FIG. 2, the imaging console 5 includes a control unit 51, a storage unit 52, an input unit 53, a display unit 54, a communication I / F 55, a network communication unit 56, and the like. 57 is connected.

The control unit 51 includes a CPU, a RAM, and the like. The CPU of the control unit 51 reads out various programs such as system programs and processing programs stored in the storage unit 52, expands them in the RAM, and executes various processes according to the expanded programs.
For example, the control unit 51 makes an inquiry to the HIS / RIS 7 via the network communication unit 56 every predetermined time, and acquires the imaging order information newly registered in the HIS / RIS 7.
For example, the control unit 51 executes an imaging control process described later, and the imaging console 5 controls the radiation source 3 and the FPD 9 to perform imaging based on the imaging order information acquired from the HIS / RIS 7. Then, the control unit 51 extracts a local region that does not include an edge from the subject region of the medical image acquired by photographing, and the body motion of the subject at the time of photographing based on the high spatial frequency component extracted from the extracted local region. Is determined, and the determination result is displayed on the display unit 54. That is, the control unit 51 implements functions as a region extraction unit, a body movement determination unit, and a control unit.

The storage unit 52 includes, for example, an HDD (Hard Disk Drive), a semiconductor nonvolatile memory, or the like.
The storage unit 52 stores various programs and data.
For example, the storage unit 52 stores various programs for executing the above-described imaging control processing, and image processing parameters for adjusting image data of medical images to an image quality suitable for diagnosis for each region. (Look-up table defining gradation curve used for gradation processing, enhancement degree of frequency processing, etc.) are stored.

The storage unit 52 stores imaging conditions (radiation irradiation conditions and image reading conditions) in association with imaging regions. The radiation irradiation conditions are, for example, an X-ray tube current value, an X-ray tube voltage value, a filter type, an SID (Source to Image-receptor Distance), and the like.
The storage unit 52 stores characteristic information of the FPD 9. Here, the characteristic information is a characteristic of the detecting element of the FPD 9 or a scintillator panel.
The storage unit 52 stores imaging order information transmitted from the HIS / RIS 7 every predetermined time.

  The input unit 53 includes a keyboard having character input keys, numeric input keys, various function keys, and the like, and a pointing device such as a mouse, and a key pressing signal pressed by the keyboard and an operation signal by the mouse. Are output to the control unit 51 as an input signal.

The display unit 54 includes, for example, a monitor such as a CRT (Cathode Ray Tube) or an LCD (Liquid Crystal Display), and displays various screens according to instructions of a display signal input from the control unit 51.
A pressure-sensitive (resistive film pressure type) touch panel (not shown) in which transparent electrodes are arranged in a grid pattern is formed on the screen of the display unit 54, and the display unit 54 and the input unit 53 are configured integrally. It may be a touch screen. In this case, the touch panel is configured to detect the XY coordinates of the power point pressed by a finger, a touch pen, or the like as a voltage value, and output the detected position signal to the control unit 51 as an operation signal. The display unit 54 is a general PC (Personal Computer).
It may be of a higher definition than the monitor used for.

  The communication I / F 55 is an interface for connecting to the Bucky device 1, the Bucky device 2, the radiation source 3, and the FPD 9 via the access point AP and performing data transmission / reception wirelessly or by wire. In the present embodiment, the communication I / F 55 transmits a polling signal to the FPD 9 as necessary via the access point AP.

  The network communication unit 56 includes a network interface or the like, and transmits / receives data to / from an external device connected to the communication network N via a switching hub.

  The console 6 is an input device that is connected to a radiation source in the imaging room and inputs a radiation irradiation instruction.

  The HIS / RIS 7 generates imaging order information in response to a registration operation by an operator based on an inquiry result or the like. Imaging order information includes patient information such as the name, sex, age, height, weight, etc. of the patient to be the subject, information on imaging reservations such as imaging site, imaging direction, body position (standing position, standing position), imaging method, etc. Is included. Note that the shooting order information is not limited to the information exemplified here, but may include other information, or may be a part of the information exemplified above.

  The diagnosis console 8 is a computer device that acquires medical images from the server device 10 and displays the acquired images to allow a doctor to make an interpretation diagnosis.

The FPD 9 is a radiation detector that includes a control unit, a detection unit, a storage unit, a connector, a battery, a wireless communication unit, and the like.
The detection unit of the FPD 9 includes, for example, a glass substrate, and detects, at a predetermined position on the substrate, radiation that has been irradiated from the radiation source 3 and transmitted through at least the subject according to the intensity thereof. A plurality of detection elements that are converted into electrical signals and accumulated are two-dimensionally arranged. The detection element is configured by a semiconductor image sensor such as a photodiode. Each detection element is connected to a switching unit such as a TFT (Thin Film Transistor), for example, and the switching unit controls the accumulation and reading of electric signals.

The control unit of the FPD 9 controls the switching unit of the detection unit based on the image reading condition input from the imaging console, switches the reading of the electrical signal stored in each detection element, and accumulates in the detection unit. Image data (still image) is generated by reading the electrical signal. Then, the control unit outputs the generated image data to the photographing console 5 via the connector and the bucky device 1 or 2. Each pixel constituting the generated still image indicates a signal value (herein referred to as a density value) output from each detection element of the detection unit.
The connector of the FPD 9 is connected to the connector on the Bucky devices 1 and 2 side, and performs data transmission / reception with the Bucky device 1 or 2. The connector of the FPD 9 supplies power supplied from the connector of the bucky device 1 or 2 to each function unit. Note that the battery may be charged.
Further, the FPD 9 is configured to perform battery drive and wireless communication when used alone without being attached to the Bucky. When the FPD 9 is loaded into the Bucky device 1 or 2, the battery / wireless system is switched from the battery / wireless system to the wired / power supply system by connecting the connector. Can do. Accordingly, even when a plurality of patients are continuously photographed, it is not necessary to worry about running out of the battery.

  The server device 10 includes a database that stores medical image data and interpretation reports transmitted from the imaging console 5 in association with imaging order information. Further, the server device 10 reads a medical image from the database in response to a request from the diagnostic console 8 and transmits the medical image to the diagnostic console 8.

(Shooting operation)
Next, a photographing operation in the medical image photographing system 100 will be described.
FIG. 3 shows a flow of imaging control processing executed in the imaging console 5. The shooting control process of FIG. 3 is executed in cooperation with the control unit 51 of the shooting console 5 and the program stored in the storage unit 52.

  First, an operator such as a photography engineer sets the FPD 9 in the bucky device 1 or the bucky device 2. Next, the input unit 53 of the shooting console 5 is operated to display a shooting order list screen for displaying a list of shooting order information on the display unit 54. Then, by operating the input unit 53, the shooting order information of the shooting target and the Bucky ID used for shooting are designated from the shooting order list screen.

  In the imaging console 5, when imaging order information and a Bucky ID for imaging are designated by the input unit 53 (Step S <b> 1), the radiation source 3 and the FPD 9 are activated, and the radiation source 3 is used according to the used Bucky device. Is adjusted in direction and position. When the position of the FPD 9 or the bucky device is adjusted according to the subject by the imaging engineer, the direction and position of the radiation source 3 are adjusted accordingly (step S2). Further, the radiation irradiation condition and the image reading condition corresponding to the part to be imaged are read from the storage unit 52, the radiation irradiation condition is set in the radiation source 3, and the image reading condition is set in the FPD 9 via the Bucky device. (Step S3). When preparation for imaging is completed, the engineer operates the console 6 to input a radiation irradiation instruction.

  When a radiation irradiation instruction is input from the console 6 (step S4; YES), the radiation source 3 and the FPD 9 used for imaging are controlled, and the subject is imaged (step S5). Specifically, a medical image that is a still image of the subject and one or several dark images for offset correction are captured under the conditions set in step S3. The image data of the medical image and the dark image generated by the imaging are input from the FPD 9 to the imaging console 5 via the bucky device and stored in the storage unit 52.

Next, correction processing and image processing are performed on the medical image obtained by imaging (step S6), and the processing proceeds to step S7. In step S6, correction processing such as offset correction processing, gain correction processing, defective pixel correction processing, and lag (afterimage) correction processing using the above-described dark image based on the characteristic information of the FPD 9 stored in the storage unit 52. Is done as needed. Further, as the image processing, gradation processing, frequency enhancement processing, grain suppression processing, and the like corresponding to the imaging region are performed.
If there are a plurality of FPDs 9, the characteristic information is stored in the storage unit 52 in association with the identification ID of each FPD 9, and the identification ID is acquired from the FPD 9 via the used Bucky device. Correction processing and image processing may be performed based on the characteristic information corresponding to the identified ID.
The medical image that has been subjected to the correction process and the image process is stored in the storage unit 52.

  Next, an image confirmation screen on which the medical image subjected to the correction process and the image process is displayed is displayed on the display unit 54 (step S7), and a body movement determination process is executed (step S8). The image confirmation screen is a screen on which a medical image that has been subjected to correction processing and image processing is displayed. Although not particularly illustrated, an enlarged display frame 541a and a pop-up screen 541b in the body motion warning screen 541 shown in FIG. 14 are displayed here. It is a screen that has not been done. Other screen layouts and buttons to be displayed are the same as those of the body movement warning screen 541.

  Hereinafter, an example of the body movement determination process executed in step S8 of FIG. 4 will be described in detail. Here, as one embodiment, a process for determining the presence or absence of body motion of a subject at the time of photographing from a medical image obtained by photographing the front of the chest will be described.

  FIG. 4 shows the flow of the body movement determination process executed in the imaging console 5 in step S8. The body movement determination process shown in FIG. 4 is executed in cooperation with the control unit 51 of the imaging console 5 and the program stored in the storage unit 52.

First, an outline of the algorithm of the body movement determination process shown in FIG. 4 will be described with reference to FIGS. 5A to 5C and FIG.
5A to 5C are diagrams schematically illustrating a spatial frequency response (response) in a medical image.
5A to 5C, the horizontal axis is an axis indicating a spatial frequency band in the horizontal direction, and the vertical axis is an axis indicating a spatial frequency band in the vertical direction. In both axes, the center is the lowest frequency band, and the farther from the origin (center), the higher the spatial frequency band. In FIGS. 5A to 5C, the intensity of the response in each spatial frequency band is shown in shades, and the stronger the response, the darker the density.

FIG. 5A is a diagram schematically illustrating a spatial frequency response in a still image. As shown in FIG. 5A, in the still image, the response of the high spatial frequency is approximately the same in each direction on average.
FIG. 5B is a diagram schematically illustrating a spatial frequency response in a still image (body motion image) having body motion in the horizontal direction. In the body motion image, the response of the spatial frequency in the body motion direction is weakened, and the strength of the response changes depending on the direction. When there is a body movement in the lateral direction, the spatial frequency response in the lateral direction becomes weak as shown in FIG. 5B.
FIG. 5C is a diagram schematically illustrating a spatial frequency response in an image including a lateral edge. FIG. 6 is a diagram illustrating the relationship between the vertical spatial frequency and the response in an image including a horizontal edge and an image including no edge. As shown in FIG. 5C, in an image including an edge, a strong high spatial frequency is generated in a direction perpendicular to the edge, and the strength of the response varies depending on the direction. In addition, as shown in FIG. 6, an image including an edge has a higher response in the high-frequency spatial frequency band than an image not including an edge.
In the algorithm of the body motion determination process shown in FIG. 4, the presence or absence of body motion is determined based on the characteristics of the spatial frequency response in these still images, body motion images, and edge images.

  In the body movement determination process, first, the medical image (the medical image after the correction process and the image process in step S6) to be subjected to the body movement determination process is divided into a plurality of small areas (for example, a rectangular area of 2 mm × 2 mm). (Step S101). By dividing the medical image to be processed into small regions, the region in the lung field that is the subject region included in the medical image is also divided into small regions.

Next, a region in the lung field is extracted (step S102).
There are roughly three peaks in the histogram of signal values of still images taken of the chest. Appearing in the high signal area is a direct X-ray area in which X-rays are detected directly without passing through the subject, and appearing in the low signal side is in a trunk area such as a heart or bone with low X-ray transmittance. is there. Appearing between them is a lung field region that penetrates the lungs. Therefore, in step S102, the threshold values of the trunk region and the lung field region (low signal side threshold value 1) and the direct X-ray region threshold value (high signal) by discriminant analysis or the like from the signal value histogram of the medical image to be processed. Side threshold values 2) are obtained, and regions having signal values between threshold values 1 and 2 are extracted as lung field regions. FIG. 7 shows an example of the lung field region extracted in step S102. A region L surrounded by a thick dotted line is a lung field region.
The lung field region may be extracted first, and the extracted lung field region may be divided into a plurality of small regions.

Next, a local region not including an edge is extracted from the extracted lung field region (step S103).
In a region including an edge such as a rib, as described above, many high spatial frequency components are included. Therefore, in step S103, first, a high spatial frequency component is extracted by allowing each small region in the lung field region to pass through a high-pass filter that extracts only a high spatial frequency component in a predetermined band. Next, the maximum value or integral value of the response in the band (see FIGS. 6 and 8) between the Nyquist frequencies fN and fN−Δf (Δf is a predetermined value) in the extracted high spatial frequency component is calculated, Either the calculated maximum value or the integral value is compared with a threshold value set in advance for each value. If the calculated value is larger than the threshold value, it is determined that an edge is included in the small area. Here, since an area not including an edge is extracted, either the calculated maximum value or the integral value is compared with a threshold value set in advance for each value, and a small area equal to or smaller than the threshold value is defined as a local area that does not include an edge. Extracted. FIG. 9 shows a local region that does not include an edge extracted in step S103. A small area P in the figure is the extracted local area. Although only a part of the small area P is indicated in FIG. 12, the small area P surrounded by a rectangle having the same line type / size is the small area P. Note that the edge detection may use another method (for example, a method using a vertical profile or a horizontal profile of a medical image).

Next, in each extracted local region, an index value representing the response of the high spatial frequency component for each direction is calculated (step S104).
As shown in FIG. 10, the high spatial frequency component in the vertical direction is between -Δfw / 2 and Δfw / 2 (Δfw is a predetermined value) in the horizontal spatial frequency, and in the vertical spatial frequency. The response of each band (band included in Ah shown in FIG. 10) surrounded by the Nyquist frequency fN and fN−Δfb (Δfb is a predetermined value) is acquired, and the maximum value or the integrated value is obtained in the vertical direction. Is calculated as a response index Rh of the high spatial frequency component.
As shown in FIG. 10, the high spatial frequency component in the horizontal direction is between -Δfw / 2 and Δfw / 2 in the vertical spatial frequency and between the Nyquist frequencies fN and fN−Δfb in the horizontal spatial frequency. The response of each band (band included in Aw shown in FIG. 10) is acquired, and the maximum value or integral value is calculated as the response index Rw of the high spatial frequency component in the horizontal direction.
Here, an integral value is used. Here, the description is limited to the vertical and horizontal two-directional bands, but the response index values may be calculated in four-directional bands to which diagonal two-directions Au and Ad shown in FIG. 11 are further added.

Next, a body motion feature amount is calculated based on the response index value calculated for each local region, and based on the calculated body motion feature amount, the presence or absence of body motion of the subject at the time of shooting is determined ( Step S105).
In step S105, as shown in FIG. 12, first, average values Rh ′ and Rw ′ for each direction are calculated for the responses Rh and Rw for each direction calculated for each local region. Next, the absolute value | R′h−R′w | of the calculated difference value of Rh ′ and Rw ′ is calculated as a body motion feature amount, and when this body motion feature amount is larger than a predetermined threshold value, It is determined that there is a body movement in a direction in which the numerical value is small (lateral direction in FIG. 12). In addition, in the case of four directions with two diagonal directions added, an average value is calculated for each direction for the response index for each direction calculated for each local region, and the difference value between the average value in the vertical direction and the horizontal direction And the absolute value of the difference between the average value in the diagonal direction is calculated and compared, and the larger value is used as the body movement feature amount. When the determination of the presence / absence of body movement is completed, the process proceeds to step S9 in FIG.

In step S9 of FIG. 3, it is determined whether or not the subject has body movement based on the determination result of the body movement determination process. If it is determined that there is no body movement in the subject (step S9; NO), the process proceeds to step S12.
On the other hand, if it is determined that the subject has body movement (step S9; YES), the body movement part is determined based on the position information and the high spatial frequency component of the local area not including the edge extracted in the body movement determination process. An enlarged area for enlarged display is determined (step S10).
FIG. 13A to FIG. 13C show an enlarged region determination process in step S10 of FIG. As shown in FIG. 13A, first, a plurality of enlargement candidate regions (region 1 and region 2 in FIG. 13A) having a predetermined size are set in the lung field region. Next, as shown in FIG. 13B, the total of the body motion feature amounts calculated from the local regions in each expansion candidate region is acquired. Then, as illustrated in FIG. 13C, an enlargement candidate region (region 2 in FIGS. 13A and 13B) having the largest total body motion feature amount is determined as the enlargement region.

Next, a body motion warning screen 541 in which the determined enlarged area is displayed in an enlarged manner is displayed on the display unit 54 (step S11).
FIG. 14 shows an example of the body movement warning screen 541. On the body motion warning screen 541, a frame 541a indicating the determined enlarged area is superimposed and displayed on a medical image (image processed) acquired by imaging, and an enlarged image in which the enlarged area is enlarged and A screen 541b on which a warning message such as “There is a risk of body movement” is displayed as a pop-up. The body motion warning screen 541 displays an output button B1 and a re-shooting button B2. The output button B1 is a button for instructing to output and save the displayed medical image to the server device 10. The re-imaging button B2 is a button for instructing to discard the displayed medical image and perform re-imaging.

  In step S12, when the re-imaging button B2 is pressed by the input unit 53 (step S12; YES), the processed medical image stored in the storage unit 52 is deleted (step S13), and the process is performed in step S2. Return to. On the other hand, when the re-imaging button is not pressed by the input unit 53 (step S12; NO) and the output button B1 is pressed (step S14; YES), the image data of the medical image that has been subjected to image processing by the network communication unit 56 is obtained. It is transmitted to the server device 10 in association with the shooting order information specified in step S1 (step S15), and the shooting control process is terminated. In the server device 10, the received image data of the medical image is stored in the database in association with the imaging order information.

As described above, according to the medical image photographing system 100, the control unit 51 of the photographing console 5 extracts a subject area from a medical image that is a still image acquired by photographing a subject, and the subject area To extract a local region that does not contain high spatial frequency components due to edges. Then, a high spatial frequency component is extracted from the extracted local region, and based on the extracted high spatial frequency component, the presence or absence of body movement of the subject at the time of photographing is determined, and the determination result is output by the output unit.
Therefore, since the presence / absence of body motion of the subject is determined using a region not affected by the edge portion of the structure, it is possible to accurately determine the presence / absence of body motion.

  Further, by extracting a high spatial frequency component from each of the plurality of local regions and determining the presence or absence of body movement of the subject at the time of shooting based on the high spatial frequency components extracted from the plurality of local regions, one Compared with the case where a high spatial frequency component extracted from a local region is used, it is less affected by noise and the local region itself, and the presence / absence of body movement can be determined with higher accuracy.

  Further, by extracting high spatial frequency components for a plurality of directions and determining the presence or absence of body movement of the subject at the time of shooting based on the extracted high spatial frequency components for the plurality of directions, the direction of body movement is determined. Thus, it is possible to determine the presence or absence of body movement with higher accuracy.

  In addition, when it is determined that there is a body movement, the control unit 51 determines an area to be enlarged and displayed from the medical image based on the position information of the extracted local area and the high frequency component extracted from the local area. The determined area is enlarged and displayed on the display unit 54. Therefore, the operator can easily confirm the body movement on the image.

In addition, the said embodiment is a suitable example of this invention, and is not limited to this.
For example, in the above embodiment, it has been described that the medical image obtained by the FPD 9 is displayed on the display unit 54 for confirmation or the body motion determination process is performed, but the thinning process is performed on the medical image by the FPD 9. It is also possible to display the thinned medical image on the display unit 54 for confirmation or to perform body movement determination processing. In this way, the data transfer time, image processing time, body movement determination time, etc. from the FPD 9 can be reduced.

  In the above embodiment, the body movement determination process has been described by taking the case where the imaging region is the front of the chest as an example. However, in other imaging regions, the region of interest extracted in step S102 differs depending on the imaging region. Can use the same technique as the above-described body movement determination process.

  Further, in the above-described embodiment, it has been described that display is output on the display unit 54 as output means for outputting a warning (determination result) when it is determined that there is body movement in the subject. Or the like. Further, in the above-described embodiment, the case has been described as an example in which a warning that is the determination result is output when it is determined that there is body movement in the subject, but even when it is determined that there is no body movement in the subject. This may be displayed on the display unit 54.

  In the above embodiment, the medical image capturing system that generates a medical image using FPD has been described as an example. However, the means for generating a medical image is not limited to this, and for example, CR is used. Also good.

  In the above description, an example in which an HDD or a semiconductor nonvolatile memory is used as a computer-readable medium for the program according to the present invention is disclosed, but the present invention is not limited to this example. As another computer-readable medium, a portable recording medium such as a CD-ROM can be applied. Further, a carrier wave is also applied as a medium for providing program data according to the present invention via a communication line.

  In addition, the detailed configuration and detailed operation of each device constituting the medical image photographing system can be changed as appropriate without departing from the spirit of the invention.

100 Medical Imaging System 1 Bucky Device 2 Bucky Device 3 Radiation Source 5 Imaging Console 51 Control Unit 52 Storage Unit 53 Input Unit 54 Display Unit 55 Communication I / F
56 Network communication section 57 Bus 6 Console 7 HIS / RIS
8 Diagnosis console 9 FPD
10 Server device

Claims (6)

Image generating means for capturing a subject and generating a medical image as a still image;
A region extracting means for extracting a subject region from the medical image and extracting a local region not including an edge from the subject region;
A body motion determination unit that extracts a high spatial frequency component from the local region extracted by the region extraction unit, and determines presence / absence of body motion of the subject at the time of photographing based on the extracted high spatial frequency component;
Control means for causing the output means to output the determination result by the body movement determining means;
A medical imaging system comprising: The area extracting means divides the subject area into a plurality of small areas, and extracts a plurality of local areas not including an edge from the plurality of small areas,
The body motion determining unit extracts a high spatial frequency component from each of the plurality of local regions extracted by the region extracting unit, and based on the high spatial frequency component extracted from the plurality of local regions, the subject at the time of photographing The medical image photographing system according to claim 1, wherein the presence or absence of body movement is determined.   2. The body motion determination unit extracts high spatial frequency components in a plurality of directions, and determines presence or absence of body motion of a subject at the time of photographing based on the extracted high spatial frequency components in the plurality of directions. Or a medical image photographing system according to 2; The output means is a display means for displaying and outputting the medical image generated by the image generation means;
The control means, when it is determined that there is a body movement by the body movement determination means, based on the position information of the local area extracted by the area extraction means and the high frequency component extracted from the local area The medical image photographing system according to any one of claims 1 to 3, wherein an area to be enlarged and displayed is determined from a medical image, and the determined area is enlarged and displayed on the display means. A region extracting means for extracting a subject region from a medical image that is a still image acquired by photographing a subject, and extracting a local region not including a high spatial frequency component due to an edge from the subject region;
A body motion determination unit that extracts a high spatial frequency component from the local region extracted by the region extraction unit, and determines presence / absence of body motion of the subject at the time of photographing based on the extracted high spatial frequency component;
Control means for causing the output means to output the determination result by the body movement determining means;
A medical image processing apparatus comprising: Computer
A region extracting means for extracting a subject region from a medical image that is a still image acquired by photographing a subject and extracting a local region not including a high spatial frequency component due to an edge from the subject region;
A body motion determination unit that extracts a high spatial frequency component from the local region extracted by the region extraction unit and determines the presence or absence of body motion of the subject based on the extracted high spatial frequency component;
Control means for causing the output means to output the determination result by the body movement determining means;
Program to function as.

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