JPH01254149A - X-ray ct device - Google Patents

Abstract

PURPOSE:To obtain an enlarged picture which is changed three-dimensionally of a target part with a single scanning by, while displacing a checked body in his body shaft direction, revolving a transmitted X-ray information collecting means around the checked body and collecting transmitted X-ray information. CONSTITUTION:A checked body M is loaded on a patient table 2 and displaced in the body shaft direction together with the patient table 2. A stand revolving part 3 is revolved with being synchronized to the displacement of this patient table 2. In this stand revolving part 3, an X-ray tube 5 and an X-ray detector 6 are fit in positions to be faced each other. The X-ray detector 6 detects the transparent X-ray information from plural directions in the target part, which is changed three-dimensionally, of the checked body M and inputs the information to a data collecting system 10. From the data to be collected in the data collecting system 10, the enlarging picture of the target part, which is changed three-dimensionally, is collected.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an X-ray CT apparatus, and more specifically, the present invention relates to an X-ray CT apparatus, and more specifically, it obtains multidirectional scan images in one scan of a subject and X-ray CT that can obtain accurate enlarged images of
Regarding equipment.

(Prior Art) An overview of a conventional X-ray CT apparatus will be explained with reference to FIG.

The X-ray CT system@50 shown in the same figure irradiates X-rays from an X-ray tube 52 to a subject M lying on a top plate 51, and uses an X-ray detector 53 to detect the transmitted X-rays that have passed through the subject M. After detection, for example, a scano image S of one direction of the subject M is constructed based on this detection signal, and an image of a part of the subject MQ') that is three-dimensionally curved in the body axis direction, such as the spinal cord, is constructed. Find @K.

Then, by performing image processing on the image data constituting this image K and specifying its center position, a series of enlarged images Ox, D2, . . . as shown in the same figure are created.

Dn is displayed for diagnosis.

However, in the conventional apparatus described above, when obtaining the enlarged images D1, D2, ..., Dn, the center position of the enlargement process is specified two-dimensionally on the scano image @S in one direction. For example, it is impossible to specify the position in the depth direction (direction perpendicular to the body axis) on the scano image S. Therefore, it is not possible to accurately specify the center position of the enlarged image to be displayed, and the desired diagnostic image cannot be displayed by 1q. The problem is that I can't do it.

(Problems to be Solved by the Invention) As described above, conventional devices are unable to accurately follow three-dimensional positional changes of the target region of the subject;
There is a problem in that it is only possible to continuously obtain 1 q of images necessary for diagnosis.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an X-ray CT apparatus that can accurately and continuously obtain enlarged images of a three-dimensionally changing target region in a single scan.

[Structure of the Invention] (Means for Solving the Problems) The XIICT apparatus of the present invention includes a transmitted X-ray information collecting means rotatably arranged around a top plate, and a subject placed in one skin along with the top plate. a synchronizing means for synchronizing the operation timings of the transmitted X-ray information collecting means and the subject displacing means; and a synchronizing means for displacing the subject by the subject displacing means. Based on the transmitted X-ray information obtained from multiple directions of the three-dimensionally changing target part of the subject obtained by rotating the transmitted X-ray information collection means, scano images from multiple directions are obtained and both of these scano images are displayed. a specifying means for specifying the center position of the target region with respect to the scano images taken from the plurality of directions; and an image reconstruction means for obtaining and displaying a reconstructed image.

(Function) The function of the device having the above configuration will be explained below. The transmitted X-ray information collection means and the subject displacement means of this apparatus operate under synchronous control by the synchronization means, and when the subject displacement means displaces the subject in the body axis direction, the transmitted X-ray information collection means While rotating around the subject, it collects transmitted X-ray information from multiple directions of a three-dimensionally changing target region of the subject.

The scano-image collecting means obtains and displays a plurality of scano-images corresponding to the transmitted X-ray information from a plurality of directions. At this stage, the specifying means specifies the center position of the target part 1 for each of the plurality of scano images.

The image reconstruction means obtains and displays an arbitrary number of reconstructed images of the target region using the center position designated by the designation means as the center position of the image to be displayed.

(Example) Examples of the present invention will be described in detail below. FIG. 1 shows a schematic configuration of an X-ray CT apparatus 1 of this embodiment.

This XIjICT equipment@1 is designated as Xl in the same figure.

A gantry rotating part 3 having an insertion hole 4 rotatably arranged around the body axis of a subject M lying on a top plate 2 movable in the X2 direction, and facing opposite to the gantry rotating part 3. The X-ray tube 5 and the X-ray detector 6 are mounted in the same position, and the O° flags 7a and 180' flags 7b are fixedly arranged near the gantry rotating section 3 and below the top plate 2 so as to be arranged at 180°, respectively. and a 90' flag and a 270'' flag (not shown), a rotational position sensor 8 attached to the opposite side of the X-ray tube 5 connected to the gantry rotating section 3, and the Xl of the top plate 2.
, a top plate sensor 9 that detects displacement in the X2 direction, and a data collection system 10 that takes in the transmitted X-ray detection signal obtained by the X-ray detector 6, collects transmitted X-ray information, and outputs it. ing. Note that FIG. 1 shows a state in which the X-ray detector 6 is located vertically above the subject M, and the X-ray tube 5 is located vertically below the subject M, and this state is referred to as the "o° position". The following explanation is given as follows.

Next, the control system of the XIICT device 1 will be explained with reference to FIG.

This control system includes a CPU 11 that performs overall control, and a CPU
Transmission X-ray information collection means 1 that sends transmission X-ray information to 11
2, a pedestal part 14 that includes the pedestal rotating part 3 and the pedestal driving part 3 that applies a rotational force to the pedestal rotating part 3, the top plate 2, and a displacement force in the Xi and X2 directions on the top plate 2. A subject displacement means 16 consisting of a top drive unit 15 that provides
Rotation operation of the gantry rotating section 3 by the gantry driving section 13 and X
a synchronizing means 17 that controls the timing of exposure of the fan beam B by the wire tube 5 and controls the displacement of the top plate 2 by the top plate drive unit 15 in synchronization with the rotational operation of the gantry rotation unit 3;
The transmitted X-ray information is taken in through the CPU 11, and displayed as a Skirref image (1), a scano image composition section 18 that constitutes K2, and a display section 19 (1', 2) for the scano image.
A scanning image collecting means 20 consisting of 1. A specifying means 21, such as a keyboard, for specifying the center position (coordinates) corresponding to the three-dimensionally changing target site (the spinal cord) in the subject M for 2; The apparatus includes an image reconstruction means 22 that reconstructs a large number of images (slice images) of the target region based on information on the center position corresponding to the image and displays the images.

The synchronizing means 17 takes in the position information from the rotational position sensor 8 and the top plate sensor 9, and the position information from the rotation position sensor 8 and the top plate displacement information from the top plate sensor 9, ANDs the results, and generates a position signal. The first AND gate 23 takes in the position information from the rotational position sensor 8 and the transmitted X-ray information from the data acquisition system 10, performs an AND operation on them, and sends out the result as an X-ray detection signal. and a second AND gate 24.

The image reconstruction means 22 includes a data memory 23 that stores information on the center position designated by the designation means 21;
A computing unit 27 that performs screening processing takes in the storage information of the data memory 23 and the image information of the scano image constructed by the scano image composition unit 18, and sets the center position as the center coordinate of the image to be displayed on the subject. An image reconstruction section 26 that reconstructs a large number of enlarged slice images according to the target region of M, and an enlarged image display section 27 that displays these enlarged slice images are provided.

Next, the operation of the apparatus having the above structure will be explained with reference to FIGS. 3 to 5. The following explanation will be given assuming that t is the width of the fan beam B that passes through a portion along the body axis of the subject M, as shown in FIG.

First, while keeping the subject M on the top plate 2 at the position shown in FIG. 1 and the X-ray tube 5 and X-ray detector 6 at the O degree position, B is directed toward the subject M. The fan beam B transmitted through the object M is
It is detected by the X-ray detector 6, converted into a transmitted X-ray signal, and sent to the data acquisition system 6. The data collection system 6 processes the collected signals and converts them into transmitted X-ray information by the CPU 11 and the second
Send it to AND gate 24.

On the other hand, immediately after the fan beam B is irradiated from the X-ray tube 5, the pedestal drive unit 13 rotates the pedestal rotation unit 3 under the control of the CPU 11, and the top drive unit 15 rotates the top plate 2. For example, the object M is displaced together with the object M in the X1 direction. Eventually,
When the rotational position sensor 8 attached to the gantry rotation unit 3 rotates to the position of a 90' flag (not shown), this rotational position sensor 8 indicates that the X-ray tube 5 and the X-ray detector 6 have rotated 90'. Location information is number one. Second AND gate 23
．． 24, and the displacement information of the top plate 2 at this time is also sent from the top plate sensor 9 to the first AND gate 23.

The first AND gate 23 performs an AND operation on the position information and the displacement information, opens the gate when both are input, and sends a position signal to the CPU 11. Further, the second AND gate 24 opens the gate and sends an X-ray detection signal to the CPU 11 when both the position information and the transmitted X-ray information are input.

In the operation of this apparatus described above, when the X-ray tube 5 and the X-ray detector 6 rotate from the O degree position shown in FIG. 1 to the 90' position not shown in FIG. Under the control of the CPU 11 which receives the X-ray detection signal and the position signal, the top plate 2 is adjusted to the width t of the fan beam B as shown in FIG. 3(a).
1/2 in the X1 direction. Then, in this state, the fan beam B is emitted from the X-ray tube 5 toward the subject M, as in the case described above, and as a result, the data acquisition system 10 is directed to the side (90° position) of the subject M. The corresponding transmission X-ray information is sent to CPLJll.

Similarly, when the five X-ray tubes and the X-ray detector 6 come to the 180° position shown in FIG.
In this state, the fan beam B is irradiated in the direction from the back to the abdomen of the subject M, and the data collection system 10 collects transmitted X-ray information at this time. Send to CPU11.

Although not shown, the X-ray tube 5 and the X-ray detector 6 are 270
Exactly the same operation is performed for the ° position.

In this way, the same operation as in the above case is continuously repeated until the top plate 2 shown in FIG. Information is required.

FIGS. 4(a) and 4(b) show the above-mentioned O° position and 90' position.
O° skiseno image @S1 constructed by the scano image composition unit 18 based on the transmitted X-ray information obtained by scanning the position 1q
and 90° scano image S2 are displayed on the display unit 19.

The operator of this device selects the center position C1 of the target region using the specifying means 21 with respect to the two images Sl and S2.
, C2.

The information on the center positions C1 and C2 is temporarily stored in the data memory 25 via the CPU 11.

Then, as shown in FIG. 5, the calculation unit 27 of the image reconstruction means 22 calculates the coordinates P1 (Xt, Yl) of the center position C1 in the 0° scano image and the 90' gap V image C.
Coordinates P1' of center position C2 of 2 (X2, Z2)
The three-dimensional center coordinates PO(X2, Yt) of the slice image that should actually be displayed based on .

Z2) is calculated and this value is stored in the data memory 25.

The image reconstruction unit 26 uses the value of the coordinate Pa, the 0° deviation image constructed by the scano image construction unit 18, and the 90°
'Take in the image information of the scano image and reconstruct an enlarged image (slice image) with the value of coordinate Pa as the center position.

This enlarged image is displayed on the enlarged image display section 27 and used for diagnosis.

Such an operation of the image reconstruction means 22 causes the center position C1,
executed for all or desired coordinates along C2;
As a result, the enlarged display unit 27 displays an arbitrary number of accurate enlarged images corresponding to the target region K.

Note that the X coordinate shown in FIG. 5 represents the top plate position, the Y coordinate represents the lateral direction of the subject M, and the 7 coordinate represents the vertical direction of the subject M.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

[Effects of the Invention] According to the present invention described in detail above, it is possible to obtain a reconstructed image that accurately corresponds to the target region of the subject that changes three-dimensionally with just one scan, thereby improving diagnostic performance. It is possible to provide an X-ray CT device that can contribute to improvement.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a schematic configuration of an embodiment of the present invention;
Figure 2 is a block diagram showing the control system of the device, and Figure 3 (a
) is a plan view showing the top plate position at the 90' position in the same device, FIG. 3(b) is a sectional view showing the top plate position at the 180° position in the same device, and FIGS. ) are explanatory diagrams showing 0° scano image and 90° scano image, respectively.
FIG. 5 is an explanatory diagram showing the image reconstruction method of the embodiment apparatus, and FIG. 6 is an explanatory diagram showing the image reconstruction method of the conventional apparatus. DESCRIPTION OF SYMBOLS 1... X-ray CT apparatus, 12... Transmission X-ray information collection means, 16... Subject displacement means, 20... Scano image collection means, 22... Image reconstruction means. Figure 1 CG) Figure 3 Figure 5

Claims (1)

[Claims] a transmitted X-ray information collecting means rotatably arranged around the top plate; a subject displacement means for moving the subject along with the top plate in the body axis direction over a range of one scan;
a synchronizing means for synchronizing the operation timings of the X-ray information collection means and the object displacement means; and a synchronization means for synchronizing the operation timings of the X-ray information collection means and the object displacement means; a scanogram collecting means for obtaining scanograms from a plurality of directions based on transmitted X-ray information from a plurality of directions of a target region that changes and displaying these scanograms; and image reconstruction means for obtaining and displaying an arbitrary number of reconstructed images of the target region using the center position specified by the specifying means as the center position of the image. X-ray CT device.