US-12616431-B2 - Imaging control system and imaging control method

US12616431B2US 12616431 B2US12616431 B2US 12616431B2US-12616431-B2

Abstract

According to one embodiment, an imaging control system comprising: an X-ray imaging device; a respiratory monitor; and a control calculating device; the control calculating device comprising: a respiratory waveform divider to slice at least one of cycle and amplitude in a respiratory waveform of the respiratory motion included in the respiratory data into multiple specific fragments, an image data sorter to acquire a rotational angle indicating a rotational position of the rotating gantry from a gantry controller for controlling a rotation of the rotating gantry, and to sort the X-ray images contained in the image data every specific fragment into multiple X-ray images, and a three-dimensional reconstructor to reconstruct the multiple X-ray images categorized every specific fragment based on the rotational angle of the rotating gantry at shooting to generate multiple three-dimensional reconstructed images.

Inventors

Kosuke Nakanishi
Yasushi Iseki

Assignees

KABUSHIKI KAISHA TOSHIBA
Toshiba Energy Systems & Solutions Corporation

Dates

Publication Date: 20260505
Application Date: 20240123

Claims (14)

1 . An imaging control system comprising: an X-ray imaging device to rotate together with a rotating gantry around a patient, to radiate X-rays to the patient for taking multiple two-dimensional X-ray images, and to output image data including the multiple two-dimensional X-ray images; a respiratory monitor to watch respiratory motion of the patient and to output respiratory data indicating the respiratory motion; a control calculating device to acquire the image data from the X-ray imaging device and to acquire the respiratory data from the respiratory monitor; the control calculating device comprising: a respiratory waveform divider to slice at least one of cycle and amplitude in a respiratory waveform of the respiratory motion included in the respiratory data into multiple specific fragments, an image data sorter to acquire a rotational angle indicating a rotational position of the rotating gantry from a gantry controller for controlling a rotation of the rotating gantry, and to sort the multiple two-dimensional X-ray images contained in the image data by each of the multiple specific fragments into the multiple two-dimensional X-ray images, and a three-dimensional reconstructor to reconstruct the multiple two-dimensional X-ray images categorized by each of the multiple specific fragments based on the rotational angle of the rotating gantry at shooting to generate multiple three-dimensional reconstructed images, wherein the control calculating device is configured to determine whether the image data is appropriate for generating the multiple three-dimensional reconstructed images, and to discard at least a portion of the image data that is determined to be inappropriate; and the control calculating device determines that, for the multiple two-dimensional X-ray images acquired during one rotation of the rotating gantry and categorized in each predetermined fragment of amplitude in the respiratory waveform, the image data is inappropriate for generating the multiple three-dimensional reconstructed images in a case of uneven numbers of the multiple two-dimensional X-ray images among each predetermined fragment of amplitude in the respiratory waveform, and discards all the image data at that time without generation of the multiple three-dimensional reconstructed images.
2 . The imaging control system according to claim 1 , wherein the control calculating device further comprises a moving image generator to generate a moving image from the multiple three-dimensional reconstructed images along a time axis of the respiratory waveform and to output the moving image.
3 . The imaging control system according to claim 1 , wherein the control calculating device further comprises a moving image generator to generate a moving image capable of being played back from maximum inspiration and maximum expiration from the multiple three-dimensional reconstructed images and to output the moving image.
4 . The imaging control system according to claim 1 , wherein the control calculating device preliminarily stores information on a divisional region and a number of divisions for slicing the amplitude into the multiple specific fragments.
5 . The imaging control system according to claim 1 , wherein the X-ray imaging device is configured to perform shooting prior to irradiation of the patient with therapeutic radiation, and the control calculating device is configured to generate the multiple three-dimensional reconstructed images for use in matching with a standard image for treatment regimen acquired in advance.
6 . The imaging control system according to claim 1 , wherein the X-ray imaging device is configured to establish a timing of shooting the multiple two-dimensional X-ray images in accordance with the respiratory waveform and a rotational speed of the rotating gantry.
7 . The imaging control system according to claim 1 , wherein the X-ray imaging device is configured to establish a timing of shooting the multiple two-dimensional X-ray images in accordance with each of an acceleration term, a constant speed term, and a deceleration term of the rotation of the rotating gantry.
8 . The imaging control system according to claim 1 , wherein the control calculating device is configured to store information indicating a relation between a position of an affected area in the patient and the rotational angle, and the X-ray imaging device is configured to establish a timing of shooting of the multiple two-dimensional X-ray images in accordance with the rotational angle.
9 . The imaging control system according to claim 1 , wherein the control calculating device is configured to correlate fragment-identifying information capable of identifying the multiple specific fragments with the rotational angle at the shooting for managing the multiple two-dimensional X-ray images.
10 . The imaging control system according to claim 1 , wherein the X-ray imaging device comprises at least two radiographic units for taking the multiple two-dimensional X-ray images at multiple shooting angles accompanied by the rotation of the rotating gantry; and the X-ray imaging device is configured to establish a shooting condition such that an X-ray image taken by a first radiographic unit of the at least two radiographic units and another X-ray image taken by a second radiographic unit of the at least two radiographic units complement between their imaging angles.
11 . The imaging control system according to claim 10 , wherein an establishment of the shooting condition includes the establishment of a rotational speed of the rotating gantry; and the rotational speed of the rotating gantry is determined based on an angle defined by shooting directions of the first radiographic unit and the second radiographic unit.
12 . The imaging control system according to claim 10 , wherein the shooting condition is established such that the multiple shooting angles at a times of shooting in the multiple two-dimensional X-ray images corresponding to one of the multiple specific fragments are equally spaced.
13 . An imaging control method comprising steps of: acquiring a rotational angle indicating a rotational position of a rotating gantry rotating around a patient from a gantry controller that controls the rotating gantry; acquiring image data from an X-ray imaging device that outputs the image data including multiple two-dimensional X-ray images taken by the X-ray imaging device rotating with the rotating gantry and radiating X-rays to the patient; acquiring respiration data from a respiration monitor that watches respiratory motion of the patient and to output the respiration data indicating the respiratory motion; slicing at least one of cycle and amplitude in a respiratory waveform of the respiratory motion included in the respiration data into multiple specific fragments; categorizing the multiple two-dimensional X-ray images contained in the image data based on each of the multiple specific fragments; reconstructing the multiple two-dimensional X-ray images categorized every specific fragment based on the rotational angle of the rotating gantry at a time of shooting to produce a three-dimensional reconstructed image, wherein, in the reconstructing of the multiple two-dimensional X-ray images, it is determined whether the image data is appropriate for generating the three-dimensional reconstructed image, and at least a portion of the image data that is determined to be inappropriate is discarded; and it is determined that, for the multiple two-dimensional X-ray images acquired during one rotation of the rotating gantry and categorized in each predetermined fragment of amplitude in the respiratory waveform, the image data is inappropriate for generating multiple three-dimensional reconstructed images in a case of uneven numbers of X-ray images among predetermined fragments of amplitude, and all image data acquired at that time is discarded without generation of the multiple three-dimensional reconstructed images.
14 . The imaging control system according to claim 1 , wherein the control calculating device determines that if the number of the multiple two-dimensional X-ray images categorized into a certain fragment of amplitude among predetermined fragments of amplitude is insufficient for generating the multiple three-dimensional reconstructed, the image data is inappropriate for generating the multiple three-dimensional reconstructed, and discards the multiple two-dimensional X-ray images categorized into the certain fragment of amplitude.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a Continuation application of No. PCT/JP2021/038227, filed on Oct. 15, 2021, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD Embodiments of the present invention relate to technology of controlling imaging. BACKGROUND Radiation therapy involves irradiating an affected area of a patient with radioactive rays to damage the cells in that area. If the irradiation is not accurately directed to the affected area in such a case, normal tissues may also be damaged. Accordingly, computed tomography (CT) is introduced in advance to determine the three-dimensional geometry of the affected area, so that a treatment regimen is formulated to most effectively irradiate the affected area other than normal tissue with radioactive rays. In order to irradiate the affected area with radioactive rays in accordance with this treatment regimen, the body posture of the patient at a time of treatment regimen must be aligned with the body posture of the patient at the time of treatment. The three-dimensional reconstructed image output from the CT imaging device is thus sectioned into a CT image at the time of treatment regimen, and this CT image is checked against an X-ray image taken from an X-ray imaging device in the treatment room immediately before treatment to determine a position of the affected area accurately. However, the X-ray imaging device can merely acquire a two-dimensional image of a patient; hence, it is difficult to perform highly accurate checking of the X-ray image against the reconstructed image obtained by the CT imaging device. Some conventional techniques involve recognition of the three-dimensional position of the affected area captured during CT imaging, selection of an image that satisfies the conditions for irradiation with radioactive rays, performs reconstruction of the image to generate a CT image. This technique allows the affected area to be irradiated with radioactive rays as per the treatment regimen, even if breathing or other movements occur. Since this technique, however, selects only images that satisfy the conditions for irradiation, it does not accurately find changes in the location of the affected area. If the relative configuration of the skeletal and organs at the time of treatment regimen shift immediately prior to treatment, for example, it is difficult to distinguish whether such a shift is due to differences in the conditions of the patient on that day or to normal respiratory motion. Another technique is also known that slices the amplitude of a respiratory waveform into multiple fragments and generates a tomographic image (CT image) using only projection images corresponding to a certain fragment. For example, use of only a projection image corresponding to a fragment of minimum amplitude can generate a tomogram corresponding to the state of maximum expiration. However, this technique is intended to reduce artifacts in tomographic images but not to find the condition of the patient over the entire respiratory motion that fluctuates between maximum inspiration and expiration. PRIOR ART DOCUMENT Patent Document [Patent Document 1] JP 2015-29793 A[Patent Document 2] JP 2010-505562 A[Patent Document 3] JP 2021-45459 A SUMMARY Problem to be Solved by Invention An object of the present invention is to provide a technique of controlling imaging that can accurately find the condition of the patient, which fluctuates with respiratory motion, in computed tomography for radiation therapy. Means for Solving Problem In one embodiment of the present invention, an imaging control system comprising: an X-ray imaging device to rotate together with a rotating gantry around a patient, to radiate X-rays to the patient for taking multiple two-dimensional X-ray images, and to output image data including the multiple two-dimensional X-ray images; a respiratory monitor to watch respiratory motion of the patient and to output respiratory data indicating the respiratory motion; and a control calculating device to acquire image data from the X-ray imaging device and to acquire the respiratory data from the respiratory monitor; the control calculating device comprising: a respiratory waveform divider to slice at least one of cycle and amplitude in a respiratory waveform of the respiratory motion included in the respiratory data into multiple specific fragments, an image data sorter to acquire a rotational angle indicating a rotational position of the rotating gantry from a gantry controller for controlling a rotation of the rotating gantry, and to sort the X-ray images contained in the image data every specific fragment into multiple X-ray images, and a three-dimensional reconstructor to reconstruct the multiple X-ray images categorized every specific fragment based on the rotational angle of the rotating gantry at shooting to generate multiple three-dimensional reconstructed images. Effects of Invention According to