JPS6116538Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a radiation tomography apparatus.

A radiation tomography apparatus attempts to obtain a distribution image of a radiation source in a certain cross section of a patient.
In other words, RI (radioactive isotope) is taken into the patient's body as a drug, and when this RI accumulates in a specific organ, the radiation emitted from the RI is detected from outside the patient's body, and the RI in a specific cross section is detected.
The aim is to find out the distribution state of . Therefore, it is necessary to set a cross section that crosses the organ to be diagnosed, and perform radiation detection operations from 360° directions within this cross section. Since this cross section is normally set perpendicular to the patient's body axis, the radiation detector is rotated around the patient around the patient's body axis.

By the way, as a radiation detector, a two-dimensional radiation detector such as an Anger-type scintillation camera that is normally used in a scintillation camera device is used, but this type of detector is extremely heavy and requires a large rotational drive mechanism. However, there are disadvantages in that it is extremely difficult to precisely control even small angle rotations.

In view of the above, the present invention is designed by swinging the radiation shielding plate of the collimator placed in front of the two-dimensional radiation detector, so that the two-dimensional radiation detector itself can be rotated intermittently at large angles. It is an object of the present invention to provide a radiation tomography apparatus that solves the above problems.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a collimator 2 is arranged in front of an angle-type scintillation camera 1, and this camera 1 is attached to the tip of an L-shaped support member 3. This support member 3
is supported by a rotary drive section 4 having a built-in rotary drive motor, and this rotary drive section 4 is held by a stand 5. A patient 7, who is the subject, is lying on a bed 6, and the position of the bed 6 is set so that the body axis O coincides with the center of rotation.

According to the present invention, the radiation shielding plate of the collimator 2 is designed to swing, and the radiation incident direction changes as the radiation shielding plate swings. That is, as shown in FIG. 2, this collimator 2 is made up of a large number of thin radiation shielding plates that are assembled in a direction perpendicular to each other and provided with a large number of lattice-like slits. The object is held rotatably, and a drive mechanism (not shown) moves the object in the vertical direction (second direction).
(See Figure B) to the left and right within a range of θ/2 (See Figures 2A and C). Therefore, as the radiation shielding plate of the collimator 2 swings, the radiation incident direction changes within the range of angle θ. Then, as shown in FIG. 3, the camera 1 is rotated intermittently. First, when camera 1 is stopped at the solid line position, collimator 2
The radiation shielding plate is swung to swing the radiation incident direction by an angle θ. Then, the camera 1 is rotated about the central axis O and stopped at the position indicated by the two-dot chain line. In this stopped state, collimator 2
The radiation shielding plate is rotated in the incident direction by swinging, and the camera 1 is rotated again. If this is repeated and the camera 1 rotates once, the necessary data can be obtained. When the camera 1 is rotated intermittently in this manner, the angle of rotation at one time can be up to the angle θ at most, and there is no need to control rotation of minute angles.

The data from the camera 1 obtained during the swinging of the radiation shielding plate of the collimator 2 is sent to the computer along with information on the angular position of the camera 1 and the angular position of the collimator 2, and has already undergone a known calculation process. A tomographic image is constructed.

As described above with respect to the embodiments, according to the present invention, the radiation shielding plate of the collimator is oscillated to control minute angular changes in the direction of radiation incidence, so highly accurate control is possible. becomes. Furthermore, more dense and accurate information regarding the angle of the radiation incident direction can be obtained. Furthermore, if you leave the two-dimensional radiation detector fixed and use it as a simple scintillation camera, by swinging only the radiation shielding plate of the collimator, you can collect data from different directions without moving the two-dimensional radiation detector. Obtainable.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of an embodiment of the present invention, FIG. 2 is a schematic front view showing A, B, and C for explaining the movement of the collimator 2, and FIG. FIG. 3 is a schematic front view for explaining rotational movement. 1... Anger type scintillation camera, 2...
... Collimator, 3 ... L-shaped support member, 4 ... Rotation drive section, 5 ... Stand, 6 ... Bed, 7 ...
…patient.

Claims (1)

[Scope of utility model registration request] A radiation tomography system in which a two-dimensional radiation detector is rotated around the subject while facing toward the subject, and data obtained from the detector is processed by a computer to construct a distribution image of the radiation source in a desired cross section within the subject. In the imaging device, the detector is intermittently rotated at predetermined angles, and the radiation shielding plate of the collimator provided on the front surface of the detector is oscillated, and this oscillation causes the direction of radiation incidence to be controlled within a predetermined angular range. A radiation tomography apparatus characterized in that the radiation shielding plate of the collimator is oscillated while the detector is stopped every intermittent rotational operation. .