JP4876466B2 - Mammography system - Google Patents

Description

The present invention relates to a mammography system .

  A breast image obtained by performing mammography using radiation is widely used as a medical image for diagnosis. Appropriate control of the radiation dose to be exposed in mammography is important for preventing an excessive exposure dose to the subject. In addition, radiation dose and image quality are very closely related, and if the dose is not appropriate, the granularity of the image will increase, so the imaging performance of the subject will deteriorate and the diagnostic performance will deteriorate, so the radiation dose to be exposed will be controlled appropriately. It is also important to ensure diagnostic performance of images. Therefore, an imaging device that performs mammography is equipped with an automatic exposure control device (AEC) and is controlled so that the radiation dose is appropriate.

  The automatic exposure control has a sensor that detects a radiation amount that has passed through the subject on the opposite side between the radiation source and the subject, and controls the radiation exposure time according to the radiation amount detected by the sensor. Since most breast cancers arise from mammary tissue, it is important to expose the mammary tissue to an optimal dose of radiation. Therefore, the radiographer needs to position the sensor so that the position of the sensor for detecting the radiation dose corresponds to the highest density part of the mammary gland in order to expose the optimal dose of radiation to the mammary tissue region. is there.

As an aid to this automatic exposure control, for example, in Patent Document 1, the position of the sensor is indicated on the breast before the X-ray is exposed by projecting the sensor position on the breast. The technology is described.
JP-A-8-80295

  However, in Patent Document 1 described above, it is impossible to know whether or not the sensor position used for detecting the radiation dose is suitable for the high density position of the mammary gland. It was necessary to judge whether proper exposure control was performed.

The problem of the present invention is that a radiographer can output images with an appropriate exposure dose by associating and outputting the position of a sensor used for detection of a radiation dose transmitted through a breast as a subject at the time of radiography and a breast image. It is possible to confirm whether or not it has been done.

In order to solve the above-mentioned problem, the invention described in claim 1
Breast radiography apparatus provided with a plurality of sensors for detecting the amount of radiation transmitted through the breast and performing automatic exposure control, a display unit for displaying a breast image obtained by the mammography apparatus, and a control apparatus A mammography system comprising:
Sensor selection means for selecting any one of the plurality of sensors by a user operation;
The mammography apparatus performs the automatic exposure control based on the sensor selected by the sensor selection unit to generate the breast image,
The control apparatus annotates the breast image displayed on the display unit at a position corresponding to the selected sensor so as to be able to recognize whether the sensor selected by the user operation is appropriate. It is characterized by superimposing.

The invention according to claim 2 is the invention according to claim 1,
Said control device, said determining whether a proper image has been captured on the basis of whether the selected position of the sensor and mammary gland density position of the breast images match, the display of the determination result It is characterized by being displayed on the screen.

The invention according to claim 3 is the invention according to claim 2 ,
If it is determined that proper imaging has not been performed, the control device selects one of the plurality of sensors that is closest to the breast high-density position of the breast image, and the selected sensor An annotation is superimposed on the breast image corresponding to the position and displayed on the display unit .

According to the present invention, since outputs in association with the sensor information and the breast image including the position information of the sensors used to detect the amount of radiation transmitted through the breast it is subject during radiography, radiographic technician, breast images It is possible to confirm whether or not imaging with an appropriate exposure dose has been performed by checking which part of the sensor has been used to control the radiation dose.

[First Embodiment]
First, the configuration of the first exemplary embodiment of the present invention will be described.
FIG. 1 is a conceptual diagram showing an overall configuration of a medical image photographing system 100 in the present embodiment. As shown in FIG. 1, the medical image photographing system 100 includes an imaging device 10, a reading device 20, a control device 30, and an image output device 40. The control device 30 includes the imaging device 10, the reading device 20, and an image. The output device 40 is configured to be connected so that data can be transmitted and received.

Hereinafter, each device constituting the medical image photographing system 100 will be described.
The imaging device 10 exposes radiation to a patient's breast as a subject and captures a radiation image of the breast. In the present embodiment, an example in which a photographing apparatus of a type that performs photographing using the cassette C is applied will be described.

  In FIG. 2, the example of an external appearance structure of the imaging device 10 is shown. FIG. 3 shows a functional configuration of the photographing apparatus 10. As shown in FIG. 3, the photographing apparatus 10 includes a control unit 11, an operation unit 12, a display unit 13, a photographing unit 14, a barcode reader 15, a sensor unit 16, and an I / F 17. Connected by.

  The control unit 11 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and reads various processing programs stored in the ROM, In cooperation with each other, various processes including a process on the imaging apparatus side in a breast image imaging process to be described later are executed, and imaging of each part of the imaging apparatus 10 such as automatic exposure control in the radiation source 145 and rotation control of the imaging unit 14 is performed. Radiographic imaging of the subject is performed by comprehensively controlling the operation, and imaging information (information on the sensor used to detect the amount of radiation transmitted through the subject at the time of imaging (used for detection among the sensors 1 to 7 of the sensor unit 16) Cassette C cassette that uses the sensor position information, size information, etc.) and shooting conditions (sensor sensitivity, tube voltage value, filter type, etc.) for shooting. To the control device 30 with D.

  The operation unit 12 includes a key for inputting various setting conditions, and outputs an operation signal corresponding to the operated key to the control unit 11. For example, the position and size of each sensor in the sensor unit 16 used to detect the amount of radiation that passes through the subject during imaging, sensor sensitivity, tube voltage value, filter type, radiation exposure timing, and rotation angle of the imaging unit 14 Various keys such as numeric keys and function keys for inputting values and the like are provided.

  As shown in FIG. 2, the display unit 13 includes a display display 131 such as an LCD (Liquid Crystal Display), and displays various display information such as input information from the operation unit 12 and processing results by the control unit 11. This is displayed on the display 131.

  The imaging unit 14 performs imaging by exposing a subject to radiation, and as shown in FIG. 2, the imaging unit 14 can be moved up and down along a column 142 so that the height can be adjusted according to the position of the patient's breast. It is configured to be movable up and down in the direction indicated by the arrow α, and is configured to be rotatable about the support shaft 144 (to be rotatable in the direction indicated by the arrow β) in order to change the shooting direction. The rotation can be manually rotated by the imaging engineer, or can be instructed to rotate by operating the operation unit 12.

  In the imaging unit 14, a radiation source 145 that generates radiation and an imaging table 146 for mounting the breast are arranged to face each other, and the breast placed on the imaging table 146 is pressed to compress the breast. A compression plate 147 is provided. FIG. 4 shows a side view of the photographing unit 14. As shown in FIG. 4, the photographing unit 14 is configured so that the cassette C can be attached to the cassette holder 146 a of the photographing stand 146. The cassette C incorporates a photostimulable phosphor plate, absorbs radiation transmitted through the subject, and records the radiation image. The cassette C is provided with a bar code B indicating identification information for uniquely identifying the cassette C (hereinafter referred to as a cassette ID). On the other hand, the imaging table 146 is provided with a barcode reader 15 for reading the barcode B displayed on the cassette C. The barcode B of the cassette C is provided at the center of one side of the back side of the recording surface of the radiation image. Further, the barcode reader 15 in the photographing stand 146 is provided at the center of one side of the back side of the cassette C in the cassette insertion direction.

  When the imaging technician attaches the cassette C to the imaging table 146, for example, by inserting the side on which the barcode B is pasted to face the insertion port of the cassette holder 146a, the imaging engineer records the subject to be recorded on the cassette C. The direction can always be specified in one direction.

  The barcode reader 15 outputs the cassette ID obtained by reading the barcode B of the attached cassette C to the control unit 11.

  Note that the barcode B and the barcode reader 15 are installed at the same positions when the cassette C is mounted on the imaging table 146, and the installation positions shown in FIG. Not limited to.

  As shown in FIG. 4, the sensor unit 16 is a sensor that is provided below the cassette C mounted on the cassette holder 146a and detects radiation that has passed through the breast and the cassette C. For example, a photomultiplier, an ion It is comprised by a chamber or a semiconductor.

  FIG. 5 shows an arrangement example of the sensor unit 16. FIG. 5A shows a small sensor arrangement example, and FIG. 5B shows a large sensor arrangement example. The sensor unit 16 is arranged so that the plurality of sensors 1 to 7 shown in FIG. 5 are fixed to be parallel to the lower surface of the cassette C attached to the cassette holder 146a. It can be used selectively. In FIG. 6, the internal structural example of each sensor 1-7 is shown. As shown in FIG. 6, the sensors 1 to 7 each have six detection units a to f, and when the detection at the large size is instructed from the control unit 11, the six sensors a to f When the detection unit is used and detection by the control unit 11 is instructed to be performed in a small size (small), radiation is detected using the three detection units a to c, and a detection signal is output to the control unit 11 To do. In the control unit 11, when the detection signal from the selected sensor exceeds a preset threshold value, automatic exposure control is performed to control the radiation source 145 to stop radiation exposure. In the present embodiment, the sensor to be used is selected from a plurality of sensors 1 to 7 that are fixedly arranged, but can be moved to the lower surface of the cassette C attached to the cassette holder 146a. One or more sensors may be provided, and the photographing engineer may move the sensor to an arbitrary position to position the sensor.

  The I / F 17 is an interface for performing data input / output between the imaging device 10 and the control device 30.

  A reading device 20 shown in FIG. 1 is a device that reads a medical image recorded in a cassette C and obtains digital image data. The reading device 20 irradiates the photostimulable phosphor sheet of the cassette C with excitation light, photoelectrically converts the photostimulated light emitted from the sheet, and A / D-converts the obtained image signal for medical use. Get the image data of the image. The reading device 20 includes a barcode reader (not shown), reads the cassette ID from the barcode B attached to the cassette C, and controls the image data of the medical image and the cassette ID in association with each other via an interface (not shown). Output to device 30. When the cassette 20 is mounted, the reading device 20 detects the mounting error in the top and bottom (upper and lower) direction and the vertical direction by not being able to read the cassette barcode by a bar code reader (not shown). The mounting direction is always constant (same direction).

  The control device 30 is a medical image photographing support device for supporting radiography of a subject by a photographing engineer. A cassette ID and photographing information are input from the photographing device 10, and a cassette ID and medical image data are read from the reading device 20. Is input, the imaging information and the medical image data are displayed on the display screen in association with each other. Further, the quality of imaging is determined based on the sensor information included in the imaging information and the medical image data, and the determination result is displayed on the display screen. As a result of the determination, if it is determined that the shooting is not appropriate, the shooting conditions including the optimum sensor position and size are determined and displayed on the display screen.

  FIG. 7 shows a functional configuration example of the control device 30. As shown in FIG. 7, the control device 30 includes a control unit 31, an operation unit 32, a display unit 33, an image processing unit 34, an I / F 35, and the like, and each unit is connected by a bus 36.

  The control unit 31 includes a CPU, a RAM, a ROM, and the like, reads out a system program and various processing programs stored in the ROM, and controls mammography processing described later in cooperation with the read program. Various processes including apparatus side processes are executed.

  The operation unit 32 includes a keyboard having a cursor key, numeric input keys, various function keys, and the like, and a pointing device such as a mouse, and controls an instruction signal input by key operation or mouse operation on the keyboard. To 31. The operation unit 32 may include a touch panel on the display screen of the display unit 33, and in this case, an instruction signal input via the touch panel is output to the control unit 31.

  The display unit 33 is configured by a monitor such as an LCD or a CRT, and displays an input instruction, data, or the like from the operation unit 32 in accordance with an instruction of a display signal input from the control unit 31.

  In accordance with an instruction from the control unit 31, the image processing unit 34 subjects the input image data to frequency enhancement processing for adjusting the sharpness of the image, gradation processing for adjusting the density and contrast, or an image with a wide dynamic range. Various image processing such as dynamic range compression processing is performed so as to be within an easy-to-view density range without degrading the contrast of details.

  The I / F 35 is an interface for performing data input / output between the control device 30 and each of the imaging device 10, the reading device 20, and the image output device 40.

  The image output device 40 is a device that records and outputs an image on a film based on an image signal input from the control device 30.

Next, the operation in this embodiment will be described.
FIG. 8 is a flowchart showing a breast image photographing process (breast image photographing process A) executed in the medical image photographing system 100. Note that the control device 30 realizes a control means by executing processing on the control device side of the breast image photographing processing.

  First, the cassette C is mounted on the imaging table 146 of the imaging apparatus 10 by the imaging engineer (step S1). In the photographing apparatus 10, when the cassette C is mounted in the correct direction, that is, with the barcode reader 15 and the barcode B facing each other, the barcode B is read by the barcode reader 15 and the cassette ID is acquired. Is called. If the cassette C is not mounted in the correct direction and the barcode cannot be read, an error message notifying the mounting error is displayed on the display unit 13.

  Next, the imaging engineer positions the imaging, and arranges the breast as the subject on the imaging table 146, compression of the breast by the upper and lower sides of the compression plate 147, rotation of the imaging unit 14, input of imaging conditions, and the like ( Step S2). At the same time, the sensor unit is positioned by selecting any one of the sensors 1 to 7 of the sensor unit 16 used for radiation dose detection by the operation of the operation unit 12 by the imaging technician (step S3).

  In radiography, granularity (roughness) occurs in an image obtained when the radiation dose is not sufficient, and a good image suitable for diagnosis cannot be obtained. On the other hand, if the radiation dose is too large, the exposure amount of the subject increases, which is not preferable. In view of this, the imaging apparatus 10 performs automatic exposure control for controlling the radiation dose to be exposed according to the detection signal from the sensor unit 16. Here, the breast is mainly composed of mammary gland tissue and other adipose tissue that spreads from the nipple toward the chest wall, and the mammary gland tissue has a characteristic that it easily absorbs radiation, and the adipose tissue easily transmits radiation. Yes. Breast tissue is susceptible to lesions such as cancer, and because radiation is most easily absorbed in the high density area of the mammary gland, a sufficient dose of radiation must be exposed to the highest breast density area. In this case, an image suitable for diagnosis cannot be obtained, which affects the diagnosis. Therefore, it is suitable for diagnosis to perform radiography by selecting a sensor at a position corresponding to the portion of the arranged subject having the highest breast density (position facing the radiation source 145 across the breast high density region). It is important to get an image. Since the location of the mammary gland and the distribution of density differ depending on the patient and cannot be determined from the appearance, the radiographer determines the experience based on the patient's age, breast hardness, etc. Make a selection.

  After positioning and selection of a sensor to be used, radiation is exposed from the radiation source 145 and imaging is performed. That is, when radiation exposure from the radiation source 145 is started in response to an imaging instruction from the operation unit 12, and the detection signal input from the selected sensor exceeds a preset threshold value in the control unit 11. In addition, the radiation source 145 is controlled to stop radiation exposure (step S4). Here, as described above, each of the sensors 1 to 7 of the sensor unit 16 has the detection units a to f, and the control unit 11 includes the detection units a to f in the selected sensor. A detection signal is output from each. In the control unit 11, for example, the average of the detection signals may be calculated, and when the average value exceeds a preset threshold value, the radiation exposure from the radiation source 145 may be stopped. The radiation exposure from the radiation source 145 may be stopped when the detection signal of the detection sensor with the smallest amount of radiation transmission, that is, the detection signal with the smallest detection signal exceeds a preset threshold value.

  After shooting, in the shooting device 10, shooting information including sensor information and other shooting conditions is associated with the cassette ID and output to the control device 30 (step S5). Here, the sensor information includes the position information of the sensors 1 to 7 selected in the sensor unit 16, and when the sensor has two or more sizes as in the present embodiment, the size information also includes Including. For the position information, the sensor number (numbers 1 to 7) may be used as the position information, or the XY coordinate position of the medical image may be used as the position information. When the sensor position information is used as the sensor number, it is assumed that the control device 30 holds XY coordinate information corresponding to the sensor number. Moreover, you may include information, such as the magnitude | size of each detection part af existing inside the selected sensor, a position, and the radiation dose which reached | attained each detection part.

  When the photographing is completed, the photographed technician attaches the cassette C that has been photographed to the reading device 20 to the reading device 20 (step S6). In the reading device 20, when the cassette C is mounted in the correct direction, the cassette ID is read by the barcode reader. When the cassette C is mounted in the correct direction, the reading device 20 reads an image recorded on the mounted cassette C (step S7), and the obtained medical image data and the cassette read. The ID is associated and output to the control device 30 (step S8).

  In the control device 30, when imaging information including sensor information and imaging conditions is input from the imaging device 10, and medical image data is input from the reading device 20, imaging information with a matching cassette ID, medical image data, and (Step S9), an annotation indicating the position and size of the sensor used at the time of photographing is superimposed on the medical image based on the position information and size information included in the sensor information (step S10). The medical image on which the annotation is superimposed is displayed and output on the same display screen of the display unit 33 as output means together with the character information indicating the imaging condition (step S11). Note that the output means is the image output device 40, the image with the annotation superimposed on the medical image and the imaging condition data are output to the image output device 40, and the annotation is superimposed on the recording medium such as film from the image output device 40. The medical image and the photographing conditions at the time of photographing the medical image may be recorded and printed out.

  FIG. 9 shows an example of a screen 331 displayed on the display unit 33 in step S11. As shown in FIG. 9, in step S11, an annotation indicating the sensor position (indicated by P in the figure) and the position of the detection unit (indicated by Q in the figure) used for shooting is superimposed on the image area 331a of the screen 331. The obtained medical image is displayed, and in the imaging information area 331b, sensor information (sensor position number (Position; one of 1 to 7), sensor size (Size; large or small), detection unit number (Sens. NO .; any of a to f) and imaging conditions (sensor sensitivity (AECsens), breast thickness (Thickness), tube voltage (kVp), filter type (filter), exposure dose (mAs)) are displayed. As described above, since the mammary gland tissue easily absorbs radiation, the transmission of radiation is less than that of other regions, and the region becomes a low-density region on a medical image. The sensor displayed on the image It is possible to visually determine whether or not automatic exposure control has been performed by using a sensor at a position that coincides with a portion having the highest breast density (indicated by M in the figure) by comparing the position and the medical image. If the sensor position used deviates from the part with the highest breast density, the automatic exposure control will cause the radiation exposure before the radiation exposure reaches a sufficient dose in the part with the highest breast density. As a result, the image is stopped and the image does not have sufficient diagnostic performance.

  Next, the control device 30 determines whether or not the imaging device 10 has performed imaging based on the sensor information input from the imaging device 10, imaging information including imaging conditions, and image data of a medical image input from the reading device 20. Performed (step S12). Here, the quality of imaging is whether or not imaging was performed with an appropriate exposure dose. Specifically, the area where the mammary gland is dense and the position of the sensor used for detection coincided (the sensor's When the position is included in the mammary gland high-density region), it is determined that imaging is performed with an appropriate exposure dose, that is, imaging is satisfactory.

FIG. 10 shows the determination process executed in step S12 of FIG. The determination means is realized by executing the processing.
First, the sensor position and the mammary gland high density position are collated (step S101). As a method for extracting a high density position of a mammary gland, for example, a signal value of a medical image is binarized using an appropriate threshold value, a boundary between “0” and “1” is traced, and a breast region is extracted and extracted. In the breast region, the frequency of the signal value is obtained for each region of the sensor size used for imaging, and the region (position) having the highest lowest signal value frequency is extracted as the breast high density position. Then, the sensor position is compared with the extracted mammary gland high density position.

  As a result of the collation, if the sensor position matches the high density position of the mammary gland (step S102; YES), it is determined that proper imaging has been performed (OK), and the determination result is displayed on the display unit 33 (step S103). . If the sensor position does not match the mammary gland high density position (step S102; NO), it is determined that proper imaging has not been performed (NG), and the determination result is displayed on the display unit 33 (step S104).

  In the determination process, when it is determined that proper shooting has not been performed, a re-shooting proposal process is executed (step S13).

FIG. 11 shows the re-photographing proposal process executed in step S13 of FIG. By executing this processing, a photographing condition determining unit is realized.
First, the sensor position closest to the high density mammary gland position extracted in the determination process is selected (step S201). Next, a sensor size that matches the range of the high density portion of the mammary gland is selected (step S202). Next, an annotation indicating the selected sensor position and size, that is, an annotation indicating the optimal position and size is superimposed on the medical image (step S203), and the medical image on which the annotation is superimposed is obtained as a result of the imaging determination. It is displayed and output on the same display screen of the display unit 33 together with the photographing conditions including the information of the proposed optimum sensor position and sensor size (step S204). Examples of imaging conditions other than the sensor position and sensor size include sensor sensitivity. The sensor sensitivity can be determined based on, for example, a detection signal from the sensor (a radiation amount reaching the sensor) and an exposed radiation amount. It should be noted that the determination result of imaging quality, the image in which the annotation is superimposed on the medical image, and the data of the optimal imaging conditions are output to the image output device 40, and the determination result is recorded on the recording medium such as a film from the image output device 40. The medical image on which the annotation indicating the sensor position and size is superimposed and the imaging condition at the time of imaging the medical image may be recorded and printed out.

  FIG. 12 shows an example of a screen 332 displayed on the display unit 33 in step S204. FIG. 12 shows a display example when it is determined in step S12 that the shooting is not appropriate. As shown in FIG. 12, in step S204, a medical image on which an annotation indicating the sensor position used at the time of imaging is superimposed is displayed in the image area 332a of the screen 332, and the determination result and proposal are displayed in the imaging information area 332b. The imaging conditions (here, sensor sensitivity, sensor position, sensor size) including the optimum sensor information to be displayed are displayed.

  As a result, the radiographer checks whether the radiation dose is controlled by the sensor corresponding to which part of the medical image, confirms whether or not radiography is performed with an appropriate exposure dose, and re-photographs. Therefore, it is possible to easily determine whether or not a good image can be obtained by photographing under the necessity of re-shooting and under what shooting conditions. In addition, it is possible to reduce the number of times of radiation exposure to the subject due to inappropriate imaging conditions during re-imaging. Since the distribution and density of the mammary glands are difficult to judge from the appearance of the breast, it has conventionally been possible that the imaging engineer cannot select an appropriate sensor position at the time of re-imaging, and further re-imaging may occur, but the screen 332 By displaying annotations indicating the sensor position and size together with the breast image captured in FIG. 5 and displaying character information indicating these pieces of information, the imaging technician can select which sensor at which position to shoot. Regardless of this, it is possible to easily grasp and optimal automatic exposure control can be performed. In the present embodiment, the sensor position, sensor size, and sensor sensitivity at the time of re-imaging are proposed, but other imaging conditions may be proposed. If the determination result is OK, the determination result is displayed together with the medical image on the screen 332.

  If it is determined that the imaging engineer needs to re-shoot according to the determination result on the screen 332 and a re-shooting instruction is input by the operation unit 32 (step S14; YES), the process returns to step S1, and the processes after step S1 are performed. Is executed again. When the operation unit 32 gives an instruction to end shooting instead of re-shooting (step S14; NO), the image processing unit 34 performs image processing such as gradation correction processing and frequency enhancement processing (step S15). The processed medical image is output to the image output device 40 (step S16), and this process ends. In the image output device 40, a medical image is recorded on a recording medium such as a film and is output as a hard copy.

  As described above, according to the control device 30, imaging information including the input sensor information and imaging conditions is associated with a medical image, and the input medical information is placed on the input medical image based on the input sensor information. Annotation indicating the position and size of the sensor that detects the amount of radiation transmission used during imaging is superimposed and displayed. Further, it is determined whether or not appropriate imaging has been performed from the sensor information and the image signal of the medical image, and the determination result is displayed on the display unit. Further, when the determination result is NG, the sensor position and size corresponding to the high-density area of the mammary gland are selected based on the high-density area of the mammary gland in the medical image, and displayed on the display unit 33 as the optimum imaging condition.

  Accordingly, since the sensor information including the position information of the sensor used for detecting the radiation amount transmitted through the subject at the time of radiography and the medical image are displayed in association with each other, the radiographer can select the position corresponding to which part of the medical image. It is possible to confirm whether or not imaging with an appropriate exposure dose has been performed by checking whether or not the radiation dose has been controlled by this sensor.

  In addition, by superimposing and displaying the annotation indicating the position and size of the sensor that detects the amount of radiation used at the time of imaging on the medical image, the radiographer uses the sensor at the position corresponding to which part of the medical image to emit radiation. It is possible to more easily confirm whether the amount has been controlled.

  Moreover, since the quality of imaging is determined based on the sensor information and the medical image, and the result is displayed and output, it is possible for the imaging engineer to immediately determine the necessity of re-imaging.

  In addition, when imaging with an appropriate exposure dose cannot be performed, the optimal imaging conditions are determined and displayed based on the sensor information and medical images, so the imaging engineer determines the imaging conditions for re-imaging. It can be omitted.

[Second Embodiment]
In the first embodiment, the control device 30 detects the radiation transmission amount used at the time of imaging on the medical image input from the reading device 20 based on the sensor information input from the imaging device 10. Annotation indicating the position and size of the sensor is superimposed and displayed, and it is determined whether or not appropriate imaging has been performed from the sensor information and the image signal of the medical image, and the determination result is displayed on the display unit, and the determination result Is NG, the optimum sensor position and sensor size are displayed and output on the display unit 33, thereby supporting the photographing under the optimum photographing condition. In the second embodiment of the present invention, when the sensor position used at the time of photographing is not appropriate and good image quality cannot be obtained, the image quality is improved by image processing.

  Since the configuration of the second embodiment is the same as that described in the first embodiment, description thereof is omitted.

  FIG. 13 shows a breast image photographing process (breast image photographing process B) executed by the medical image photographing system 100 in the second embodiment. Since the processing of steps S21 to S25 in the photographing apparatus 10 of the processing is the same as steps S1 to S5 described in FIG. 8, the description thereof is omitted, and the processing of steps S26 to S28 in the reading device 20 is described in FIG. Since it is the same as steps S6 to S8, the description thereof is omitted, and the operation in the control device 30 will be described.

  In the control device 30, when imaging information including sensor information is input from the imaging device 10 and medical image data is input from the reading device 20, the imaging information having the same cassette ID is associated with the medical image data. Based on the position information and size information included in the sensor information (step S29), an annotation indicating the position and size of the sensor used at the time of imaging is superimposed on the medical image (step S30). A first button screen including an OK button and an NG button for the photographer to select an image and a determination result of the quality of the shooting is displayed (step S31).

  FIG. 14 shows an example of the first button screen. As shown in FIG. 14, on the first button screen, an annotation indicating the position and size of the sensor used at the time of photographing is superimposed on the medical image and displayed. The mammary gland high density position is visually recognized, and the visually recognized mammary gland high density position is compared with the sensor position indicated by the annotation, and, as a result of the comparison, for example, depending on whether or not all the sensor positions are included in the mammary gland high density position, Pass / fail (OK or NG) can be determined. If the result of determination is OK, shooting can be terminated by pressing the OK button. If it is NG, it is possible to shift to a second button screen for selecting image processing conditions or re-photographing by pressing the NG button.

  If the OK button is pressed from the first button screen (step S32; YES), the process proceeds to step S39. When the NG button is pressed from the first button screen (step S32; NO), a second button screen for selecting image processing conditions or re-photographing is displayed (step S33).

  FIG. 15 shows an example of the second button screen. As shown in FIG. 15, buttons for selecting “weakening the emphasis process”, “noise suppression”, and “re-photographing” are displayed on the second button screen. Here, the radiation dose at the time of imaging is related to the density and granularity of the captured image. In a medical image capturing system that acquires a medical image as a digital image, image processing, specifically, Since the processing for automatically adjusting the density suitable for diagnosis is performed by the tone correction processing, the influence on the image quality of the output image due to the shortage of radiation dose is related to the granularity. A frequency enhancement process is performed on the medical image obtained by photographing so as to improve the sharpness of the output image. As the frequency enhancement processing, for example, an unsharp image obtained by extracting only the low frequency component of the image signal is created, and the unsharp image is subtracted from the image signal of the original image, thereby obtaining an image signal in which the high frequency component is emphasized. There are things to obtain (see, for example, JP-A-10-75395). However, when the frequency enhancement process is performed, the granularity of the image also increases. Therefore, a button for adjusting the image processing condition related to the granularity is displayed on the second button screen. By comparing the mammary gland high density area with the sensor position, for example, if the sensor position is within the mammary gland area but not where the mammary gland density is the highest, the radiographer selects the “Weakening enhancement” button and the sensor position Select the “Noise suppression” button when there is a part that protrudes from the mammary gland region, and select the “Re-photo” button when the sensor position is out of the mammary gland region. The granularity can be adjusted accordingly.

  When the “weaken enhancement process” button is pressed (step S34; YES), the frequency enhancement degree is set under a condition lower than the reference (step S35), and the process proceeds to step S39. When the “noise suppression” button is pressed (step S34; NO, step S36; YES), execution of noise suppression processing for suppressing granularity is set as an image processing condition (step S37), and the processing is performed in step S39. Migrate to As noise suppression processing, for example, there is a method using multi-resolution decomposition (see Japanese Patent Laid-Open No. 2000-306089). In this case, the noise suppression process may be performed without performing the frequency enhancement process, or the frequency enhancement process may be performed with an enhancement degree lower than the reference and the noise suppression process may be performed. When the “re-photograph” button is pressed (step S34; NO, step S36; NO, step S38; YES), the process returns to step S21.

  In step S39, the image processing unit 34 performs image processing on the medical image based on the set image processing conditions, and the image processed medical image is output to the image output device 40 (step S40). finish. In the image output device 40, a medical image is recorded on a recording medium such as a film and is output as a hard copy.

  In the breast image photographing process B, a button for selecting whether the photographing is OK or NG is displayed on the first button screen, and when the NG button is pressed, the enhancement process is performed on the second button screen. The button for selecting whether to weaken, suppress noise, or perform re-shooting is displayed, but the OK button and enhancement processing are weakened on one screen, whether to suppress noise, or perform re-shooting The selection button may be displayed to reduce the number of operations by the operator.

  As described above, according to the control device 30, imaging information including the input sensor information and imaging conditions is associated with a medical image, and the input medical information is placed on the input medical image based on the input sensor information. An OK button and an NG button for superimposing an annotation indicating the position and size of a sensor for detecting a radiation transmission amount used at the time of imaging, and selecting a medical image on which the annotation is superimposed and a determination result of the quality of the imaging. Is displayed on the display unit 33. When the NG button is displayed from the first button screen, a second button screen including a “weaken enhancement process” button, a “noise suppression process” button, and a “re-photograph” button is displayed. Based on the comparison between the sensor position and the mammary gland high-density area in the medical image, the radiographer presses the “Weaken enhancement process” button, and the enhancement level in the frequency enhancement process is set to a condition that is weaker than the standard. Emphasis processing is executed. When the “noise suppression button” is pressed, noise suppression processing is executed, and processing for suppressing granularity is executed. When the “re-photograph” button is pressed, re-photographing is executed.

  Therefore, if the sensor position deviates from the mammary gland high density region and imaging with an appropriate exposure dose cannot be performed, the frequency enhancement processing is weakened or the image granularity is adjusted by performing image processing such as noise suppression processing. Therefore, it is possible to output an image with reduced granularity without performing re-imaging unless the diagnosis is impossible, and it is possible to reduce the number of patient exposures due to re-imaging.

In addition, the description content in the said embodiment is a suitable example of the medical image imaging system 100 which concerns on this invention, and is not limited to this.
For example, in the first and second embodiments, the photographing device 10, the reading device 20, and the control device 30 have been described as separate bodies, but a device that combines the functions of these devices may be used.

  Moreover, in the said embodiment, although it was set as the structure by which the control apparatus 30 and each apparatus were directly connected, it is good also as a structure connected via the communication network.

  In the above-described embodiment, the cassette C with the built-in photostimulable phosphor plate is used, the radiographed cassette C is read by the reading device 20, and the obtained medical image data is output to the control device 30. In the above description, a medical image capturing system is described as an example. A radiation detector such as an FPD (flat panel detector) is used to convert a radiation image transmitted through a subject in the imaging apparatus 10 into visible light, and the visible light is photoelectrically converted. It is also possible to adopt a configuration in which the electric signal is detected and A / D converted and output to the control device 30 together with the photographing information.

  In the above-described embodiment, imaging at the time of mammography has been described as an example. However, the present invention can also be applied to imaging of other parts.

  In addition, the detailed configuration and detailed operation of each device constituting the medical image photographing system 100 can be changed as appropriate without departing from the spirit of the present invention.

1 is a diagram showing an overall configuration of a medical image photographing system 100 according to the present invention. 1 is an external view of a photographing apparatus 10. FIG. 2 is a block diagram illustrating a functional configuration of the imaging apparatus 10. FIG. FIG. 3 is a diagram schematically illustrating a side surface of a photographing unit. It is a figure which shows the example of arrangement | positioning of the sensors 1-7 of the sensor part 16, (a) is a figure which shows the example of small sensor arrangement, (b) is a figure which shows the example of large sensor arrangement. It is a figure which shows the detection parts af of each sensor 1-7 of the sensor part 16. FIG. 2 is a block diagram showing a functional configuration of a control device 30. FIG. 5 is a flowchart showing a breast image photographing process A executed in the medical image photographing system 100. It is a figure which shows an example of the screen 331 displayed on the display part 33 in FIG.8 S11. 3 is a flowchart showing a determination process executed by a control unit 31 of the control device 30. 4 is a flowchart showing a re-photographing proposal process executed by a control unit 31 of the control device 30. An example of the screen 332 displayed on the display unit 33 in step S204 of FIG. 11 is shown. 4 is a flowchart showing a breast image photographing process B executed in the medical image photographing system 100. It is a figure which shows an example of a 1st button screen. It is a figure which shows an example of a 2nd button screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Medical imaging system 10 Imaging device 11 Control part 12 Operation part 13 Display part 14 Imaging part 142 Support | pillar 144 Support shaft 145 Radiation source 146 Imaging stand 146a Cassette holder 147 Compression plate 16 Sensor part 1-7 Sensor af detection part 17 I / F
18 bus 20 image reading device 30 control device 31 control unit 32 operation unit 33 display unit 34 image processing unit 35 I / F
36 Bus 40 Image output device B Barcode C Cassette

Claims (3)

Breast radiography apparatus provided with a plurality of sensors for detecting the amount of radiation transmitted through the breast and performing automatic exposure control, a display unit for displaying a breast image obtained by the mammography apparatus, and a control apparatus A mammography system comprising:
Sensor selection means for selecting any one of the plurality of sensors by a user operation;
The mammography apparatus performs the automatic exposure control based on the sensor selected by the sensor selection unit to generate the breast image,
The control apparatus annotates the breast image displayed on the display unit at a position corresponding to the selected sensor so as to be able to recognize whether the sensor selected by the user operation is appropriate. Breast radiography system characterized by superimposing. Said control device, said determining whether a proper image has been captured on the basis of whether the selected position of the sensor and mammary gland density position of the breast images match, the display of the determination result The mammography system according to claim 1, wherein the system is displayed on a unit.   If it is determined that proper imaging has not been performed, the control device selects one of the plurality of sensors that is closest to the breast high-density position of the breast image, and the selected sensor The mammography system according to claim 2, wherein an annotation is superimposed on the breast image corresponding to the position and displayed on the display unit.

Images