JPH0221046Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a third-generation computerized tomography (CT) device that uses a scanner consisting of an X-ray tube and a detector that rotates and irradiates X-rays in the form of a fan beam. Regarding.

In this CT apparatus, a so-called dynamic scan method has been established and adopted, in which CT images of the same cross section are obtained at different times by scanning continuously in a short period of time. However, in this dynamic scan, the rotational direction of the scanner changes, or the phase is advanced by a certain amount, and the next scan is performed, but during that time, no X-rays are emitted, and even when the image is reconstructed, It was discontinuous in time.

In view of the above problems, the purpose of this invention is to
It is an object of the present invention to provide a computerized tomography apparatus capable of continuously scanning in a fixed period of time even within a short period of time, and capable of reconstructing images continuously in time.

The above purpose is to have a first scanner consisting of an X-ray tube and a detector that narrowly face the subject and rotate together around the subject. from that position
In a computer tomography device that irradiates X-rays while rotating 180 degrees and collects transmission data, the X-rays have a phase difference of 180 degrees with respect to the first scanner and rotate in synchronization with the first scanner. A second scanner consisting of a tube and a detector is provided, and when the X-ray tube of the first scanner rotates 180 degrees, X-ray irradiation is performed by the X-ray tube of the second scanner, so that X-ray irradiation is continued. This is achieved by

Next, the gist and preferred embodiments of the present invention will be explained with reference to the drawings.

FIG. 1 shows the state of the sampling time when a dynamic scan is performed by a scanner having one set of an X-ray tube and a detector. To simplify the explanation, it is assumed that the beams are parallel. Note that the solid line indicates that X-rays are being irradiated, and the dotted line indicates that no X-rays are being emitted. As shown in the figure, there are times when the necessary data can be collected in a short time (2 seconds) like ', ', and ', and there are times when it takes a long time (6 seconds) like '''.
It is non-uniform throughout, and when the image is reconstructed, it becomes temporally discontinuous.

According to the present invention, there are two sets of X-ray tubes and detectors,
For example, A and B are prepared, and an example of their arrangement is shown in FIG. When the A-group X-ray tube is in the position, the B-group X-ray tube is in the position. The A-group X-ray tube emits X-rays while moving from one to the other. In the meantime, the B group X-ray tubes do not emit X-rays and move to , , and when the A group X-ray tubes are in the state, the B group X-ray tubes are in the state and emit X-rays. will be replaced with Group A. This operation is repeated one after another to collect transmission data and reconstruct an image, making it possible to perform continuous scanning in a fixed short period of time (2 seconds) as shown in FIG. In Figure 2 as well, the solid line is during X-ray irradiation, and the dotted line is during X-ray irradiation.
Indicates a transition where no line appears.

FIG. 4 is a diagram showing another embodiment of the present invention, in which sets A and B move so as not to interfere with each other.
When emitting X-rays, move on plane X, and when not emitting X-rays, move on plane Y.

According to the present invention, since each frame image is distributed within a short fixed time period, a computerized tomography apparatus suitable for dynamic studies can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the operation of the conventional example viewed on the time axis, FIG. 2 is an explanatory diagram of the operation of the present invention similarly viewed on the time axis, and FIG. 3 is an illustration of an embodiment in which the X-ray tube according to the present invention is moved. FIG. 4 is a diagram showing another embodiment of the present invention having mutually different planar trajectories. A and B are scanners, and X and Y are planar orbits.

Claims (1)

[Scope of utility model registration request] It has a first scanner consisting of an X-ray tube and a detector, which face the subject narrowly and rotate together around the subject, and the X-ray tube is at the initial position on the scanner's rotational trajectory. In a computerized tomography system that irradiates X-rays and collects transmission data while rotating 180 degrees from A second scanner consisting of a ray tube and a detector is provided, and when the first scanner's X-ray tube rotates 180 degrees, X-ray irradiation is performed by the second scanner's X-ray tube, and X-ray irradiation continues. A computer tomography device characterized by: