JPH0695999B2 - CT scanner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a CT scanner for performing cross-sectional imaging of a subject.

(Prior Art) With a CT scanner such as an X-ray CT apparatus, for example, when it is desired to image a cross section of a patient's chest, first, an imaging start position is set on the shoulder. The chest is photographed from the photographing start position toward the abdomen. At this time, the operator
We are shooting while looking at the reconstructed images.
Then, by displaying the reconstructed image of the abdomen, it is determined that the imaging position has reached the abdomen, and subsequent imaging is stopped.

(Problems to be Solved by the Invention) As described above, when the operator wants to capture and stop only the cross section of the chest, the operator looks at the reconstructed image,
It stops when it judges that the shooting position has reached the abdomen. That is, it is necessary to wait until the cross-sectional image is displayed as the reconstructed image after the data collection of the imaged region is completed. Therefore, before you stop shooting,
There was a drawback that it wasted time. In addition, this causes a problem that the patient is exposed to excess radiation.

Therefore, the present invention has been made in view of such a conventional situation, and an object of the present invention is to indicate that the photographing position has reached from outside the region where cross-sectional photographing is desired to outside this region. An object of the present invention is to provide a CT scanner capable of shortening the imaging stop time by judging the imaging data collected from the position and automatically stopping the imaging.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention is a storage means for storing partial cross-sectional imaging data in the vicinity of the boundary of a desired cross-sectional imaging region of a subject as reference data. And a data collection means for collecting imaging data, the cross-section imaging data collected by the data collection means, and the reference data stored in the storage means are compared, and the imaging position is outside the desired area for cross-section imaging. The comparison determining means determines whether or not it reaches, and the stop determining means stops the subsequent photographing when the comparison determining means determines that the photographing position reaches outside the desired cross-section photographing area.

(Operation) In the above-described configuration, the present invention is configured such that the cross-sectional imaging data of a part of the region in which the cross-sectional imaging of the subject is desired is previously stored.
It is stored in the storage means as reference data. Every time an image is taken in the image capturing desired region, the collected image capturing data and the reference data are compared by the comparing and determining means to determine whether or not the image capturing position has reached outside the image capturing desired region. As a result, when it is determined that the shooting position has reached the outside of the desired shooting area, subsequent shooting is stopped.

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

FIG. 1 is a block diagram showing the configuration of an embodiment relating to the CT scanner of the present invention.

The gantry 1 is configured to rotatably support the X-ray tube 3 and the detector 5, and rotationally scan the X-ray tube 3 and the detector 5 while imaging a cross section of a patient (not shown) as a subject inserted into the insertion port 7.

The X-ray tube 3 irradiates X-rays to the imaging position of the patient to perform cross-sectional imaging.

The detector 5 detects the X-ray data transmitted through the patient and sends the detected data to the data collection unit 9.

The data collection unit 9 collects the data sent from the detector 5, and transfers the collected count data to the memory 11 or the data comparison / determination unit 13.

The memory 11 stores the count data transferred from the data collection unit 9 as reference data.

The data comparison / determination unit 13 takes in the count data transferred from the data collection unit 9 according to an instruction from the rotational position detection unit 15. Further, the data comparison / determination unit 13 calculates the counted data and the reference data stored in the memory 11, and compares the calculation result with a preset threshold value. Further, when the data comparison / determination unit 13 determines that the photographing position has reached the outside of the desired photographing region based on the comparison result, it notifies the system control unit 17 of this.

The rotational position detection unit 15 detects that the rotational positions of the X-ray tube 3 and the detector 5 have reached a predetermined position, and instructs the data comparison / determination unit 13 to capture the count data.

When the system control unit 17 is notified by the data comparison and determination unit 13 that the imaging position has reached the outside of the desired imaging region, the system control unit 17 instructs the gantry 1 to stop the X-ray irradiation.

As described above, one embodiment of the present invention is configured. Next, the operation of the present invention will be described in the case of imaging a chest.

FIG. 2 is a flow chart for explaining the operation of the present invention.

The patient is inserted into the insertion opening 7 and the shoulder is set to the photographing position (step 101).

Using this position as the imaging start position, the X-ray tube 3 and the detector 5 are rotated and scanned, and the cross-sectional imaging of the chest is started toward the abdomen (step 103).

The count data collected by the data collection unit 9 is stored in the memory 11 as reference data at an arbitrary imaging position on the chest (step 105). A profile of chest count data stored in the memory 11 is shown in FIG. At this time, the rotational positions of the X-ray tube 3 and the detector 5 are stored by the rotational position detector 15.

Furthermore, the cross-sectional image of the chest is advanced toward the abdomen, and the count data is continuously collected by the data collection unit 9 every time the image is captured (step 107).

When the rotational positions of the X-ray tube 3 and the detector 5 come to the position stored by the rotational position detecting unit 15 in the imaging after the count data of a part of the chest is stored in the memory 11, this is detected. Detected by the unit 15. As a result, the rotational position detection unit 15 instructs the data comparison / determination unit 13 to fetch the count data. The data comparison / determination unit 13 that has received this instruction outputs the count data captured and collected at this rotational position to the data collection unit 9.
(Step 109).

The data comparison / determination unit 13 calculates the ratio between the count data fetched from the data collection unit 9 and the reference data stored in the memory 11. Furthermore, with this calculation result,
The preset threshold value is compared (step 111).
~ 113).

If the calculation result is smaller than the threshold value by this comparison, it is determined that this imaging position is still on the chest. On the contrary, if the calculation result is larger than the threshold value, it is determined that this imaging position has reached the abdomen (step 115).

When the data comparison and determination unit 13 determines that the shooting position is still on the chest, steps 107 to 115 are repeated.

On the other hand, when it is determined that the shooting position has reached the abdomen,
This is transmitted to the system control unit 17. As a result, the system control unit 17 issues an instruction to stop shooting to the gantry 1.
Is output to and shooting is stopped (step 117).

Here, the operation of the data comparison / determination unit 13 when the imaging position reaches the abdomen will be described with reference to FIGS. 3 and 4.

As shown in FIG. 3 (B), the profile of the count data obtained by imaging and collecting the abdomen is different from the profile of the reference data of the chest stored in the memory 11 (FIG. 3 (A)). The data comparison / determination unit 13 calculates the ratio of these count data (FIG. 4). Furthermore, since the area of the shaded area in FIG. 4 is larger than the preset threshold value, it is determined that the imaging position has reached the abdomen.

In this way, when the imaging position moves from the chest to the abdomen, the imaging is automatically stopped due to the difference in the collected data.

Further, according to the present invention, as shown in FIG. 5, it is possible to start photographing from the middle of the chest. In this case, when the shooting position reaches the abdomen, the shooting is automatically stopped, the shooting start position is automatically returned, and this time, the shooting is performed toward the shoulder. Furthermore, when the shoulder is reached, shooting is automatically stopped.

Further, according to such an invention, it is particularly effective in the case of performing helical imaging while helically scanning while the X-ray tube 3 and the detector 5 continuously rotate in a fixed direction.

In the process of the data comparison / determination unit 13, the reference data and the count data are calculated as a ratio, but a difference may be taken.

Further, in the present embodiment, the determination method is based on the difference in the count data, but the present invention is not limited to this. For example, a method in which the reconstructed sectional image is binarized by a certain threshold value and the pixel ratio of this binary data is used for determination can also be used. Alternatively, in photographing the neck or the like, a method of determining that the shoulder has been reached from the difference in profile shape of the count data may be considered.

[Effects of the Invention] As described above, with the CT scanner according to the present invention, it is possible to automatically determine that the imaging position of the subject has reached outside the desired imaging region and stop the imaging. Therefore, it is possible to shorten the time required for the operator to stop the photographing. Further, along with this, it is possible to avoid exposing the subject to excessive exposure.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a CT scanner of the present invention, FIG. 2 is a flow chart for explaining the operation of the present invention, and FIGS. 3 to 4 are data comparison / determination shown in FIG. FIG. 5 is a schematic diagram for explaining the operation of the parts, and FIG. 5 is a diagram for explaining an application example of the present invention. 9 ... Data collection unit 11 ... Memory 13 ... Data comparison / determination unit 17 ... System control unit

Claims (1)

[Claims] 1. A storage unit for storing, as reference data, partial cross-sectional radiographing data in the vicinity of a boundary of a desired cross-sectional radiographing region of a subject, a data collecting unit for collecting radiographing data, and a data collecting unit for collecting the data. Comparison determination means for comparing the cross-section imaging data with reference data stored in the storage means to determine whether the imaging position reaches outside the desired area for cross-section imaging, and the comparison determination means determines the imaging position. A CT scanner, comprising: a stopping unit that stops subsequent imaging when it is determined that the cross-sectional imaging is outside the desired area.