JPS5892975A - Scanning mechanism for radiation type computer-aided tomograph - Google Patents

Abstract

PURPOSE:To improve the quality of a tomographic image reconstructed in an ECT with data excellent in the spatial resolution by reducing the distance from the body surface to a detector with the movement of a radiation detector on the track along the surface shape of an object to be inspected. CONSTITUTION:A scintilation camera 22 with a parallel porous collimator 23 is mounted on a slider 32 to face a patient 21 through an arm 31. The slider 32 mounted on a rotary frame 33 adapted to turn is mounted on a rotating shaft 34 of a rotary driving mechanism 35 containing a motor or the like in such a manner as to be slidable radially with respect to the rotating shaft 34 and incorporates a motor or the like. The slider 32 and the rotary driving mechanism 35 are controlled with a controller 37 to position a bed 20 so that the center axis of the patient 21 roughly aligns the rotating shaft 34 of the rotary driving mechanism 35.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an emission computed tomography apparatus (hereinafter referred to as E
The present invention relates to a scanning mechanism of a CT device (abbreviated as a CT device).

In the conventional ECT device, data is collected by moving the device on a circular orbit around the radiation detection object (M@). That is, as shown in MIN, a radioactive element has been administered as a drug to the patient 11 in advance], and the radioactive element accumulates in the lesion etc. and becomes false. A scintillation camera 12 is usually used as a radiation detector, and this scintillation camera 12t1 is directed toward the person 11.

This scintillation camera 12 is equipped with a parallel multi-hole collimator 18 for defining the direction of radiation incidence. Data for reconstructing by computer the distribution of radioactive elements accumulated in the patient's lesions can be obtained from K.

Incidentally, although the collimator 18 is used to define the direction of radiation incidence, the directionality of the radiation is expanded according to the distance. Therefore, if a radiation string emitted from a radioactive isotope located far away is incident, the spatial resolution of the data will be low. The human torso is normal: Am thin in the posterior direction and on the left and right.

It has a prostrate shape that spreads out in the direction, and when cut into rounds, its surface shape is closer to an ellipse than a circle.

Therefore, since the scintillation camera 12' is moved on the circular orbit 14 as described above, when the scintillation camera 12 is located at the front and back of the patient's 11's torso, it is positioned to the left and right. Because the distance 1 from the body surface is long, only data with reduced spatial resolution can be obtained, and because of this, it has not been possible to improve the image resolution.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a scanning mechanism for an ECT apparatus that improves the above-mentioned drawback of reduced resolution by moving radiation detection on a trajectory that follows the surface shape of a subject. .

An embodiment of the present invention will be described below with reference to the drawings. In figure 7112, ped 20 soil, 1 person 2
1 is lying down. A scintillation camera 2 having a parallel multi-hole collimator 28 facing the patient 21
2 is attached to the slider 82 via 7-581t. This slider 82 is attached to a rotating frame 88 which is attached to and rotates an output rotating shaft 84 of a driving mechanism 86 that has a built-in motor.
It is mounted so as to be slidable in the radial direction with respect to the rotating shaft 84. This slider 82 has a built-in motor, and its position with respect to the rotating frame 88 is determined by a cubinion mechanism (not shown). The rotational drive mechanism 86 is held by a stun P86.

The slider 82 and the one-turn drive mechanism 85 are extended by 11ijJ by the control device 87. The bed 24 is arranged so that the center axis of the person 21 substantially coincides with the rotation axis 84 of the rotation drive mechanism 86.
The position is determined.

In this way, the position of the slider 82 (
1 rotation axis 84 (O distance l1m) is determined by the control device 87.
scintillation camera 2 from the central axis of the patient 21.
The distance to 2! l! As shown in 8a, if the surface shape of jlii210 is an ellipse, K
When the scintillation camera 22 moves on the tj elliptical orbit 24, it becomes .

In this way, the scintillation camera 22 can be moved along any trajectory along the body surface INK of the patient @21, so the scintillation camera 22f can be brought close to the body surface WM at any angle, so the angle 1jK The drawback that only data with reduced resolution can be obtained can be improved.

In the above example, assuming that the 21 viewers in the Fi corridor are elliptical, the scintillation camera is set! We have explained the case of moving on the 2t41f circular orbit 24, but the human olIIst
When cut into rings, the shape is rather close to a circle, so in this case, the clay pipe should be moved in a circular orbit, and even though the surface shape of the body is an ellipse, it depends on each person. Since they are different, it is made to move on an elliptical orbit tS accordingly. These orbits are controlled by the control device 18
7. You can do this as you like.

As described above in the embodiments, according to the present invention, data is collected by moving the radiation detection result on a trajectory where the body of the subject is 11!1 Ka.
! The distance from the peak to the detected ltI is small on average,
It has become possible to obtain r-data with excellent spatial resolution, and Ic
The image quality of tomographic images reconstructed as a T device is improved.

[Brief explanation of drawings]

[1-Schematic diagram for sharpening the conventional trajectory of grinding ore, FIG. 2 is a diagram schematically showing an embodiment of the present invention, and FIG. 8 is a diagram explaining the trajectory of an embodiment of the present invention. FIG. 11.21...Subject (II person), 12.22-Scintillation camera, 18.28-.
Collimator, 14.24... Track, 82... Slider, 88... Rotating frame, 86-- Rotating drive mechanism, 87-... Control device. Applicant: Shimadzu Corporation

Claims (1)

[Claims] +1) A rotating frame whose central axis of rotation is set to be substantially parallel to the central axis of the subject to which the radioactive element has been administered, and an upper tube of this rotating frame capable of moving in a radial direction with respect to the central axis of rotation. a detector mounted on the moving mechanism and equipped with a collimator for making radiation IMt incident from a specific direction and detecting the incident position of radiation from the subject; and a control device that controls the moving mechanism so that the detector moves on a trajectory along the surface shape of the object by a distance lIl from the rotation center axis of the detector. Scanning mechanism of type computer wI'r layer imaging device.