JP2768934B2 - X-ray tomography equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray tomography apparatus (hereinafter referred to as "X-ray CT apparatus").

[0002]

2. Description of the Related Art In recent years, spiral scanning (hereinafter referred to as "helical scanning") for efficiently collecting multi-tomographic image data has been performed by an X-ray CT apparatus. In this helical scan, a subject (usually a patient) placed on a tabletop is inserted through the imaging surface while continuously rotating fan-shaped X-rays formed in the imaging surface, and helical scan data is collected for the patient. Then, the collected data was reconstructed to obtain a multi-tomographic image.

[0003]

However, there has been a problem that the obtained tomographic image cannot be associated with the imaging position of the patient.

[0004] Further, all the reconstructed tomographic images are not necessary for diagnosis, and the reconstruction is performed wastefully, so that there is a problem that the diagnosis efficiency is low.

[0005] Furthermore, not all areas where the helical scan has been performed are necessary for diagnosis, and useless data may be collected. Therefore, there has been a problem that a patient is exposed to unnecessary X-rays.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an X-ray tomography apparatus with improved diagnostic performance.

[0007]

According to an embodiment of the present invention, there is provided a scanning device for performing a helical scan on an object by irradiating X-rays; Display means for displaying a perspective image of the range, setting means for setting a desired tomographic image forming range E based on the perspective image on the display means, and the tomographic image forming area based on the range information set by the setting means. Control means for controlling the scanning means so as to collect the spiral data over E and a correction data collection range Ec for a correction operation necessary for reconstructing a tomographic image; and Storage means for storing spiral data, designating means for designating a desired tomographic plane position based on a perspective image on the display means, and spiral data corresponding to the position designated by the designating means Is characterized in that it has a, a reconstruction means for reconstructing a tomographic image based on the extracted data extracted from the storage means.

According to the present invention having the above structure, when a desired tomographic image formation range is designated based on the fluoroscopic image displayed on the display means, the scanning means is controlled by the setting means under the control of the control means. Spiral data is collected for an area including a tomographic image formation range E and a correction data collection range Ec, and the collected data is stored in the storage unit. And
When the desired tomographic plane position is specified in the perspective image on the display means,
The spiral data corresponding to the designated position is extracted from the storage means, and the reconstruction is performed based on the extracted data. As a result, data collection for the necessary range and reconstruction of the necessary range are performed, so that the diagnostic performance can be improved and the exposure dose of the subject can be reduced.

[0009]

An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an X-ray tomography apparatus according to the present embodiment.

The present apparatus 1 includes an imaging stand 10 having an X-ray tube 4 for generating a fan-shaped X-ray 4a toward a detector 3 in an imaging hole 2 in which a subject M can be arranged and an imaging surface 2a, A bed 20 for moving a tabletop T on which a subject M is placed in the hole 2;
An X-ray tube rotation controller 5 for controlling the rotation of the X-ray tube 4; a high-pressure generator 6 for controlling X-ray irradiation from the X-ray tube 4;
, A processing unit 40 for collecting and reconstructing the projection data detected by the computer, a display unit 7 for displaying a tomographic image or a fluoroscopic image, a selection of an imaging mode such as a helical scan mode or a fluoroscopic mode, and a position for forming a tomographic image It has an input unit 8 for performing operations such as setting, and a system control unit 9 for controlling each unit of the apparatus 1 to execute a shooting mode such as a helical scan mode or a fluoroscopic mode.

The X-ray detector 3 comprises a plurality of single detectors arranged in an array along the circumferential surface of a cylindrical holding member arranged obliquely. Is always received by a part of the detector 3.

The X-ray tube rotation control unit 5 controls the X-ray tube 4 to rotate continuously around the imaging hole 2 in the same direction under the control of the system control unit 9 in the helical scan mode. In the fluoroscopy mode, the X-ray tube 4 is controlled to stop at a predetermined position.

The couch section 20 has a moving section 21 for moving the top T, and a position detecting section 22 for detecting the position of the top T with respect to the photographing surface 2a.

The processing system 40 includes a helical scan data collection unit 41 that collects helical scan data in the helical scan mode, and a perspective image data collection unit 42 that collects perspective image data in the perspective image mode. And an image reconstruction unit 43 for reconstructing a tomographic image based on the helical scan data. The helical scan data collection unit 41 collects and stores helical scan data Dh corresponding to the position information of the tabletop T from the position detection unit 22. As shown in FIG. 2, the image reconstruction unit 43 corrects the projection data Ds of の to 1 cycle near the designated tomographic plane Fs and the projection data Dc of each one cycle before and after this data Ds. The tomographic image Gs for the designated tomographic plane Fs is obtained by taking in the data for use from the helical scan data collecting unit 41 and performing reconstruction processing.

The display unit 7 can display a perspective image based on the data collected by the perspective image data collection unit 42 or a tomographic image based on the reconstruction processing of the image reconstruction unit 43 by a selection operation of the input unit 8. It is.

The system control unit 9 executes a helical scan mode or a fluoroscopic mode based on a photographing mode selection operation of the input unit 8, and in the helical scan mode, the X-ray tube 4 rotates during one rotation. The X-ray tube rotation control unit 5 and the moving unit 21 are controlled so that the plate T moves continuously for a predetermined length S. With this configuration, for example, the fan-shaped X-ray 4a is equivalent to the translational movement in the body axis direction while rotating with respect to the stationary subject M.
2 moves helically around the body axis Lc of the subject M as shown by Lx in FIG. 2, helical scan data Dh is obtained from the detector 3 and collected by the helical scan data collection unit 41. It is memorized. In the fluoroscopy mode, the X-ray tube rotation control unit 5 is controlled so that the X-ray tube 4 stops at a predetermined position such as directly above or beside the subject M, and the moving unit is configured to move the tabletop T continuously. 21 is controlled.

Next, the operation of the apparatus 1 having the above configuration will be described with reference to FIGS.

FIG. 2 is a diagram showing a flow when a tomographic image is obtained after executing the helical scan mode and the fluoroscopic mode.
FIG. 3 is a diagram showing a flow in the case where the helical scan mode is executed after the execution of the fluoroscopic mode.

A case where a tomographic image is obtained after executing the helical scan mode and the fluoroscopic mode will be described with reference to FIG.

When the operator operates the input unit 8 to select the helical scan mode, the system control unit 9 controls each unit based on the helical scan mode selection information from the input unit 8 to execute the helical scan. Shooting stand 1
Under the control of the system control unit 9, the X-ray tube rotation control unit 5 and the bed 20 collect helical scan data for the subject M, and the helical scan data collection unit 41.
First, helical scan data corresponding to the position of the top plate T is collected and stored.

Next, when the operator operates the input unit 8 to select the fluoroscopic mode, the system control unit 9 controls each unit based on the fluoroscopic mode selection information from the input unit 8 to execute fluoroscopic imaging. The imaging gantry 10, the X-ray tube rotation controller 5, and the couch 20 collect fluoroscopic image data of the subject M under the control of the system controller 9, and the fluoroscopic image data collector 4
2 collects and stores perspective image data corresponding to the position of the top plate T. After selecting the fluoroscopic mode, the helical scan mode may be selected.

When the operator operates the input unit 8 to request a display of a perspective image, a perspective image Gp is displayed on the display unit 7 as shown in FIG.

The operator operates the perspective image G displayed on the display unit 7.
When the tomographic image creation line Ls superimposed and displayed on p is moved and set, the image reconstructing unit 43 scans the data Ds and Dc corresponding to this position based on the set tomographic image creation line Ls by helical scanning. The data is read out from the data collection unit 41, reconstructed, and a tomographic image Gs of the tomographic plane Fs corresponding to the specified line Ls is displayed on the display unit 7.

When photographing is performed in this manner, a tomographic image corresponding to a desired subject photographing position can be obtained with high accuracy.

Next, the case where the helical scan mode is executed after the execution of the fluoroscopic mode will be described with reference to FIG.

When the system control unit 9 executes the fluoroscopic mode based on the operator's selection operation, the fluoroscopic image data collection unit 42 collects and stores the fluoroscopic image data of the subject M as described above. As shown in FIG. 3, a perspective image Gp is displayed on the display unit 7.

The operator operates the perspective image G displayed on the display unit 7.
Lines Ls1, Ls2 for creating tomographic images superimposed and displayed on p
Is moved, and the region sandwiched between the lines Ls1 and Ls2 is designated as a tomographic image formation range E in which a tomographic image is to be obtained, the system control unit 9 sends the range information (E) designated by the input unit 8 The control unit controls the imaging gantry 10, the X-ray tube rotation control unit 5, and the bed 20 based on the designated range E
And helical scan data collection for both ranges E and Ec of the correction data Dc collection range Ec before and after this range E.

The helical scan data collection unit 41 includes:
Helical scan data corresponding to the position of the tabletop T for both the ranges E and Ec is collected and stored, and then the image reconstruction unit 43 performs tomographic images Gs1 to Gsn at predetermined intervals within the specified range E. Is reconstructed and transferred to the display unit 7.
Based on the operation of the input unit 8, the tomographic images Gs1 to Gsn corresponding to the subject imaging position are sequentially displayed on the display unit 7.

When the image is taken in this manner, a helical scan is performed for a necessary range, so that the exposure dose of the subject can be reduced.

The present invention is not limited to the above embodiment, but can be variously modified without departing from the scope of the invention.

For example, as long as the scanning can be performed in a helical scan mode or a fluoroscopic mode, a third-generation scanner that continuously rotates the X-ray tube and the detector while maintaining the relative positions may be used.

[0033]

According to the present invention as described above, only the spiral data of the area including the tomographic image forming range E specified on the fluoroscopic image and the related correction data collecting range Ec is collected. In addition, since the reconstruction is performed by extracting the spiral data only for the tomographic plane position specified on the fluoroscopic image, it is possible to provide an X-ray tomography apparatus that improves diagnostic performance and reduces exposure dose. it can.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a view for explaining the operation of the embodiment of the present invention.

FIG. 3 is a diagram for explaining the operation of the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 X-ray tomography apparatus 2a Imaging surface 4a Fan-shaped X-ray 9 System control unit 10 Imaging gantry 22 Position detection unit 41 Helical scan data collection unit 42 Perspective image data collection unit 43 Image reconstruction unit M Subject T Top plate

Claims (1)

(57) [Claims] 1. Scanning means for performing a spiral scan on an object by irradiating X-rays, display means for displaying a perspective image of the object in a predetermined range, and a perspective image on the display means Setting means for setting a desired tomographic image forming range E based on the setting information, correction based on the range information set by the setting means, and a correction for a correction operation necessary for reconstructing the tomographic image forming range E and the tomographic image Control means for controlling the scanning means so as to collect the spiral data over a data collection range Ec; storage means for storing the spiral data collected by the scanning means; and a perspective image on the display means Means for designating a desired tomographic plane position based on the extracted data, and spiral data corresponding to the position designated by the designating means are extracted from the storage means, X-ray tomography apparatus characterized by having, a reconstruction means for reconstructing a.