JPS5835207Y2 - computer tomography device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a computed tomography apparatus capable of obtaining a radiation image of a tomographic plane perpendicular to the body axis of a subject.

Computed tomography equipment is convenient because it can obtain radiographic images of tomographic planes perpendicular to the body axis of the subject. It is necessary to obtain a transmission image.

An object of the present invention is to enable a computed tomography apparatus to obtain ordinary radiographic images, thereby enabling accurate determination of the position of the tomography plane.

An embodiment of the present invention will be described below.

In FIGS. 1 and 2, an X-ray tube 1 and a number of X-ray detectors 4 are attached to a frame 5 so as to face each other, with a collimator 2 on the X-ray tube 1 side and a collimator 3 on the detector 4 side. X-ray pencil beams 71 to 7n are formed.

The subject 10 is arranged so as to be irradiated with the beams 71 to 7n.

The beams 71 to 7n spread in a fan shape within the tomographic plane of the subject 10, and have a thickness S in a direction perpendicular to the tomographic plane (body axis direction).

By rotating the X-ray tube 1, detector 4, etc. together with the frame 5 about the center O of the subject 4, data for reconstructing an image of a tomographic plane having a thickness S can be collected.

The above configuration is that of a normal computed tomography apparatus, but according to the present invention, movable aperture plates 61 and 62 are provided in front of the collimator 3 on the detector 4 side.

As shown in FIG. 3, the movable aperture plates 61 and 62 are rotatably supported by pins 63 and 64, respectively, and are moved forward or backward by forward and backward levers 65 and 66, respectively.

During the tomography, the diaphragm plates 61 and 62 are in the retracted position, and the slits 31 to 3n of the collimator 3 are fully opened.

Each of the slits 31 to 3n has a length S corresponding to the thickness S of the tomographic plane.

The width of each slit 31 to 3n is 1 to 2 mm, and the length S is 13
It should be about mm.

When the movable diaphragm plates 61 and 62 are moved forward, it becomes as shown in FIG. 3, and each slit 31 to 3n opens at a slightly different position.

In this state, the frame 5 is translated in the horizontal direction (left and right direction) as shown by the arrow.

Then, as shown in Fig. 2, the X-ray beam 71 passes through the plane closest to the head (the plane perpendicular to the body axis) of the tomographic plane of thickness S, and the subsequent beams pass through planes that are sequentially shifted toward the legs. Therefore, the last beam 7n passes through the plane closest to the leg.

In other words, one parallel movement results in scanning by n X-ray beams shifted in the body axis direction, and when displayed based on the data obtained from the detector 4, the body is scanned as shown in Figure 4. X as n horizontal lines in a range of width S in the axial direction
A line transmission image is displayed.

From this, it can be seen that the amount of positional deviation between adjacent slits shown in FIG. 3 may be set to one or two pixels in the vertical direction on the display surface.

In this way, after collecting data for the width S in one parallel movement, move the frame 5 in the direction of the arrow (body axis direction) shown in Figure 2.
Alternatively, the above-mentioned operation is repeated, such as moving the subject 10 by the width S and performing the next parallel movement, to obtain an X-ray transmission image (FIG. 4) of a range having a predetermined length in the body axis direction.

As described above with respect to the embodiments, according to the present invention, a computed tomography apparatus capable of obtaining radiographic images can be realized.

[Brief explanation of the drawing]

Fig. 1 is a front view schematically showing an embodiment of the present invention;
The figure is a sectional view taken along the line II--II of FIG. 1, FIG. 3 is a plan view of the collimator 3 and movable aperture plates 61 and 62, and FIG. 4 is a view showing the display surface. 1...X-ray tube, 2, 3...Collimator, 4...X-ray detector, 5...Frame, 61, 62...・・Movable aperture plate, 71~7n・・
...X-ray beam.

Claims (1)

[Scope of utility model registration request] A radiation source and a number of slits arranged in a tomographic plane substantially perpendicular to the body axis of the subject and having a predetermined length in the thickness direction of the tomographic plane, and passing radiation from the radiation source through these slits. a collimator device that forms a large number of radiation beams that spread in a fan shape on a tomographic plane perpendicular to the body axis of the subject and have a predetermined thickness in the thickness direction of the tomographic plane, and a large number of radiation detectors on which each of these radiation beams enters. and a computer tomography apparatus capable of obtaining a radiographic image of the tomographic plane by rotating these three members together within the tomographic plane of the subject around the subject, wherein a plurality of the collimator devices the slits are fully opened, and elongated gaps for radiation transmission are formed diagonally across the large number of slits, and the positions where the gaps and each slit overlap are different for each slit in the thickness direction of the tomographic plane. a movable diaphragm plate that can select a diaphragm state; and a movable diaphragm plate that holds together the radiation source, the conometer device, the radiation detector, and the movable diaphragm plate when the movable diaphragm plate is in the aperture state. a frame that repeatedly moves in parallel within a plurality of planes that are parallel to the tomographic plane and whose positions differ by the radiation beam thickness, and to obtain a radiographic image of a subject having a predetermined length in the body axis direction. A computed tomography device characterized by: