JP5224057B2 - X-ray tomography equipment - Google Patents

Description

  The present invention sequentially irradiates the subject with X-rays from the X-ray tube while moving the X-ray tube and the X-ray detector in opposite directions with the subject interposed therebetween. By detecting transmitted X-rays with an X-ray detector and capturing projection images, and performing image reconstruction processing on the projection images, each imaging section parallel to the detection surface of the X-ray detector is detected within the tomographic range. The present invention relates to an X-ray tomography apparatus that generates tomosynthesis images and displays these images on a monitor.

  As one of X-ray tomography apparatuses, an apparatus configured to generate a tomosynthesis image of a subject and display it on a monitor is known (for example, see Patent Document 1). This X-ray tomography apparatus includes an X-ray tube and an X-ray detector arranged to face each other, and the X-ray tube and the X-ray detector are sandwiched between a subject placed on a top plate, While synchronously moving in the opposite directions so that the center of the X-ray beam and the center of the X-ray detector are always coincident, X-rays are sequentially emitted from the X-ray officer, and each time transmitted X-rays from the subject are emitted. Detect with an X-ray detector. Further, the X-ray tomography apparatus performs signal processing on the output from the X-ray detector and performs image reconstruction processing on a projection image captured for each X-ray irradiation to detect within a predetermined tomography range. A tomosynthesis image is generated for each predetermined photographing section parallel to the surface, and these images are sequentially displayed on the monitor.

  In this case, prior to the X-ray imaging, an operator (doctor or engineer) designates data for specifying a tomographic range in the subject (usually expressed by a distance from the top surface) and the tomographic range. Data specifying the number of imaging sections or the interval between imaging sections is input to the X-ray tomography apparatus. Based on these data, the X-ray tomography apparatus obtains the position of each imaging section within the tomography range by calculation.

  Then, the X-ray tomography apparatus performs image reconstruction processing of the projection image of each imaging section in order from one end to the other end of the designated tomography range, and the generated tomosynthesis image in the processing order. Was displayed on the monitor.

  However, since the operator normally wants to reliably obtain a tomographic image of the region of interest by one X-ray imaging, when specifying the tomographic range, the operator is expected to center on the imaging section that is expected to include the region of interest. In many cases, data is input so that a position that is a certain distance above and below the two ends of the tomography range is input, so that the tomosynthesis image of the imaging section including the region of interest is displayed on the monitor. It took time, and as a result, there was a problem that the diagnosis time was long.

JP 2003-52680 A

  Accordingly, an object of the present invention is to reduce a diagnosis time by first displaying a tomosynthesis image of an imaging section including a region of interest on a monitor.

  In order to solve the above-described problem, according to the present invention, an X-ray tube and an X-ray detector are arranged opposite to each other with a subject interposed therebetween, and the X-ray tube and the X-ray detector are arranged in opposite directions in the same plane. While moving, the X-ray tube sequentially irradiates the subject with X-rays, and each time the transmitted X-rays from the subject are detected by an X-ray detector to capture a projection image, By performing image reconstruction processing on the projection image, a tomosynthesis image is generated for each predetermined imaging section parallel to the detection surface of the X-ray detector within a predetermined tomography range, and the tomosynthesis image is In an X-ray tomography apparatus that sequentially displays on a monitor, an imaging section position specifying unit that specifies each position of the imaging section within the tomography range and a signal of a projection image for each imaging section are read. An image signal reading unit; a reconstruction processing unit configured to generate a tomosynthesis image by performing image reconstruction processing for each photographing section based on a signal of the projection image read by the image signal reading unit; and an image of the tomosynthesis image A memory for sequentially storing data; a monitor for reading out image data stored in the memory; and displaying the tomosynthesis images in the order of reconstruction processing; determining a main imaging section from the imaging sections; Sending a control signal to the processing unit, the image reconstruction processing is started from the main imaging section, and thereafter, the reconstruction processing unit is operated in order from the imaging section close to the main imaging section. An X-ray tomography apparatus comprising: a reconstruction processing control unit for controlling the X-ray tomography apparatus.

  According to a preferred embodiment of the present invention, the imaging slice position specifying unit includes a first data input unit that receives input of data specifying the tomography range, and the number of the imaging slices in the tomography range, Or a second data input unit that receives input of data designating an interval between the imaging sections, wherein the imaging section position specifying unit includes the first data input unit and the second data input unit. The position of each of the imaging sections in the tomographic range is specified based on the data input to.

According to another preferred embodiment of the present invention, the image processing apparatus further includes a region of interest specifying unit that specifies a position of the region of interest within the tomographic range, and the reconstruction processing control unit is specified by the region of interest specifying unit. The imaging section including the region of interest is determined as the main imaging section by comparing the data of the position of the area of interest and the data of the positions of the imaging sections determined by the imaging section position specifying unit. To do.
According to still another preferred embodiment of the present invention, the reconstruction processing control unit is configured to determine the tomographic range based on the position data of each of the imaging sections specified by the imaging section position specifying unit. The photographing section located at the center or closest to the center is selected, and the photographing section is determined as the main photographing section.

  According to the present invention, the reconstruction processing of the projection image of the main imaging slice including the region of interest among the imaging slices within the tomographic imaging range is first executed, and then the projection image of the projection image in order from the imaging slice that is closest to the main imaging slice. Since the reconstruction process is executed and the tomosynthesis image of the imaging section including the region of interest and the imaging section in the vicinity thereof are preferentially displayed on the monitor, the diagnosis time is greatly shortened.

It is a block diagram which shows the structure of the X-ray tomography apparatus by one Example of this invention. It is a figure explaining the principle of the image reconstruction process by the X-ray tomography apparatus of FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing the configuration of an X-ray tomography apparatus according to one embodiment of the present invention. Referring to FIG. 1, according to the present invention, a top plate 3 on which a subject M is placed, an X-ray tube 1 that irradiates the subject M on the top plate 3 with X-rays, and a subject M Is provided with a flat panel X-ray detector (FPD) 2 for detecting transmitted X-rays. The X-ray tube 1 is controlled by the X-ray tube controller 6 and supplied with a tube voltage and a tube current. Then, the X-ray tube 1 and the FPD 2 are synchronously moved in the opposite directions in the same plane by the synchronous movement mechanism 4 so that the optical axis of the X-ray tube 1 and the center of the FPD 2 always coincide with each other with the subject M interposed therebetween. You can be kidnapped. During this synchronous movement, X-rays are sequentially emitted from the X-ray tube 1 to the subject M, and transmitted X-rays from the subject M are detected by the FPD 2 each time, and a projection image is taken.

The synchronous movement mechanism 4 linearly moves the X-ray tube 1 along the linear trajectory L1 according to the control signal from the synchronous movement control unit 5, and at the same time, moves the FPD 2 in the direction opposite to the X-ray tube 1 along the linear trajectory L2. Move linearly. In this case, the synchronous movement mechanism 4 moves the X-ray tube 1 from position F1 → position F2 → position F3 while adjusting the swing angle of the X-ray tube 1 to change the X-ray irradiation angle, and positions the FPD 2 in position. Move from f1 → position f2 → position f3. Further, one or both of the X-ray tube 1 and the FPD 2 are moved manually or electrically in the X-ray irradiation direction, and the interval between the X-ray tube 1 and the FPD 2 can be adjusted.
The top plate 3 can be moved in the vertical direction and in the horizontal and vertical directions by the top plate moving mechanism 7. The top plate moving mechanism 7 operates according to a control signal from the top plate control unit 8.
The X-ray tube control unit 6, the synchronous movement control unit 5, and the top panel control unit 8 are connected to the main control unit 10, and the main control unit 10 is based on various commands and data input from the operation unit 20. A control signal is sent to each control unit 5, 6, 8.

  According to the present invention, the imaging section position specifying unit 17 that specifies the position of each imaging section within the tomographic range is also provided. The imaging section position specifying unit 17 receives the first data input unit 13 that receives data specifying the tomography range, the number of imaging sections Ma1 to Man, MA, and Mb1 to Mbn within the tomography range, or the imaging section. It has the 2nd data input part 14 which receives the input of the data which designates the space | interval between Ma1-Man, MA, Mb1-Mbn. In this case, the data specifying the tomographic imaging range is represented by the distance from the surface of the top plate 3, and the imaging cross sections are all parallel to the detection surface of the FPD 2. The imaging section position specifying unit 17 is based on the data input to the first data input unit 13 and the second data input unit 14 in the tomographic range of each of the imaging sections Ma1 to Man, MA and Mb1 to Mbn. Identify the location. In addition, it is set as the structure which the imaging | photography cross-section position specific | specification part 17 specifies the position in the tomography range of each imaging | photography cross section directly, without depending on the data input into the 1st and 2nd data input parts 13 and 14. FIG. In this case, the imaging section position specifying unit 17 does not include the first and second data input units 13 and 14.

  In addition, according to the present invention, the region of interest specifying unit 15 that specifies the position of the region of interest within the tomographic range is provided. The position of the region of interest is specified by manually inputting the distance from the surface of the top 3 to the region of interest into the region of interest specifying unit 15 by an operator (physician or engineer).

  At the subsequent stage of the FPD 2, the detection signal (projection image signal) from the FPD 2 is digitized and extracted, and the projection image signal for each photographing section is read from the output of the A / D converter 9. An image signal reading unit 11 is provided. The image signal reading unit 11 is controlled by the main control unit 10.

  Further, in the subsequent stage of the image signal reading unit 11, reconstruction is performed to generate a tomosynthesis image of the subject M by performing image reconstruction processing for each imaging section based on the signal of the projection image read by the image signal reading unit 11. The processing unit 12 is connected. The reconstruction processing unit 12 is controlled by the main control unit 10.

  FIG. 2 is a diagram for explaining the principle of image reconstruction processing by the reconstruction processing unit 12. Referring to FIG. 2, for example, regarding the imaging section MA, the pair of the X-ray tube 1 and the FPD 2 always has points G and H on the imaging section MA that are always the same point g on the detection surface 2A of the FPD 2. It is moved so that it is projected onto h. As a result, the projection position on the detection surface 2A changes at the point I that is not on the imaging section MA when the X-ray irradiation angle changes. That is, the point I is projected to the point i1 on the detection surface 2A at the position k1 when the X-ray tube 1 is at the position K1, but is at the position k2 when the X-ray tube 1 is moved to the position K2. Projected to a point i2 on the detection surface 2A.

  Then, the projection images acquired at the respective positions of the FPD 2 are subjected to image integration processing, and a tomosynthesis image of the imaging section MA is generated. At this time, since the signals at the points G and H are integrated, the points G and H are clear in the tomosynthesis image, while the signals at the point I are dispersed, so the point I is blurred in the tomosynthesis image. In this case, the degree of blur increases as the distance of the point I from the imaging section MA increases. In this way, a tomosynthesis image in which only the photographing section MA is clearly photographed is generated. In principle, the tomosynthesis images of the respective photographing sections Ma1 to Man and Mb1 to Mbn other than the photographing section MA are also generated in the same manner as in the case of the photographing section MA.

  The image data of the tomosynthesis image generated by the reconstruction processing unit 12 is sequentially stored in the memory 18, the image data stored in the memory 18 is read by the monitor 19, and the tomosynthesis image is monitored in the order of the reconstruction process. Is displayed.

  According to the present invention, the main imaging section is further determined from the imaging sections, a control signal is sent to the reconstruction processing unit 12, and the image reconstruction process is started from the main imaging section. A reconstruction processing control unit 16 that operates the reconstruction processing unit so as to be executed in order from an imaging section close to the section is provided. In this embodiment, the reconstruction processing control unit 16 uses the data of the region of interest specified by the region of interest specifying unit 15 and the data of the position of each imaging section determined by the imaging section position specifying unit 17. By comparing, the imaging section including the region of interest is determined as the main imaging section.

  Thus, according to the X-ray tomography apparatus of the present invention, the reconstruction processing of the projection image of the main imaging section including the region of interest among the imaging sections within the tomographic range is first executed, and thereafter the main imaging section. Projection image reconstruction processing is executed in order from the imaged section close to, and a tomosynthesis image of each imaged section is displayed on the monitor 19 in the order of these reconstruction processes. Thereby, the tomosynthesis image of the imaging section including the region of interest and the imaging section in the vicinity thereof are preferentially displayed on the monitor, and the diagnosis time is greatly shortened.

The method of determining the main imaging section by the reconstruction processing control unit 16 is not limited to the above embodiment.
According to another preferred embodiment, the reconstruction processing control unit 16 is located in the center of the tomographic range based on the data of the position of each imaging section specified by the imaging section position specifying unit 17, or the The photographing section closest to the center is selected, and the photographing section is determined as the main photographing section. In the case of this embodiment, the region of interest specifying unit 15 is unnecessary.
In this embodiment, for example, when the tomography range is 10 to 20 cm and the number of imaging sections is set to 6, the 14 cm imaging section located near the center (15 cm) of 10 to 20 cm is the main imaging section. The image reconstruction processing of the projection image of the main photographing section is first performed, and then the image is obtained in the order of the 16 cm photographing section, the 12 cm photographing section, the 18 cm photographing section, the 10 cm photographing section, and the 20 cm photographing section. Reconfiguration processing is performed.

  In this embodiment, when an operator usually designates a tomographic range, the positions separated by a certain distance above and below the tomographic range in which the region of interest is expected to be centered are the ends of the tomographic range. This is based on the fact that data is often input so that

1 X-ray tube 2 FPD
3 Top plate 4 Synchronous movement mechanism 5 Synchronous movement control unit 6 X-ray tube control unit 7 Top plate movement mechanism 8 Top plate control unit 9 A / D converter 10 Main control unit 11 Image signal reading unit 12 Reconfiguration processing unit 13 1 data input unit 14 second data input unit 15 region-of-interest specifying unit 16 reconstruction processing control unit 17 imaging section position specifying unit 18 memory 19 monitor 20 operation unit L1, L2 linear orbit M subject MA imaging section Ma1-Man Photographing section Mb1 to Mbn Photographing section

Claims (4)

An X-ray tube and an X-ray detector are arranged opposite to each other with the subject interposed therebetween, and the X-ray tube and the X-ray detector are moved in opposite directions in the same plane, and the X-ray tube is moved from the X-ray tube to the subject. X-rays are sequentially irradiated to the X-ray detector, and each time the transmitted X-rays from the subject are detected by an X-ray detector to capture a projection image, and the projection image is subjected to image reconstruction processing to determine in advance. In the X-ray tomography apparatus for generating a tomosynthesis image for each predetermined imaging section parallel to the detection surface of the X-ray detector and sequentially displaying the tomosynthesis image within the tomography range,
An imaging cross-section position specifying unit that specifies each position of the imaging cross-section within the tomography range;
An image signal reading unit for reading a signal of a projection image for each photographing section;
Based on the signal of the projection image read by the image signal reading unit, a reconstruction processing unit that generates a tomosynthesis image by performing image reconstruction processing for each imaging section;
A memory for sequentially storing image data of the tomosynthesis image;
A monitor that reads the image data stored in the memory and displays the tomosynthesis images in the order of reconstruction processing;
A main imaging section is determined from the imaging sections, and a control signal is sent to the reconstruction processing unit, and the image reconstruction process is started from the main imaging section, and thereafter, the imaging section is close to the main imaging section. An X-ray tomography apparatus comprising: a reconstruction processing control unit that operates the reconstruction processing unit so as to be executed in order from an imaging section.   The imaging section position specifying unit specifies a first data input unit that receives input of data specifying the tomography range, the number of imaging sections within the tomography range, or an interval between the imaging sections. A second data input unit that receives data input, wherein the imaging cross-section position specifying unit is based on data input to the first data input unit and the second data input unit. The X-ray tomography apparatus according to claim 1, wherein a position of each cross section within the tomography range is specified.   A region of interest specifying unit that specifies the position of the region of interest within the tomographic range is further provided, wherein the reconstruction processing control unit includes data on the position of the region of interest specified by the region of interest specifying unit, and the imaging section. 2. The imaging section including the region of interest is determined as the main imaging section by comparing data of positions of the imaging sections determined by a position specifying unit. 2. The X-ray tomography apparatus according to 2.   The reconstruction processing control unit is located at the center of the tomography range or closest to the center based on the data of the position of each of the imaging sections specified by the imaging section position specifying unit. The X-ray tomography apparatus according to claim 1, wherein the X-ray tomography apparatus is selected and the imaging section is determined as the main imaging section.

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