JPH05269118A - X-ray radioscopic photographing system - Google Patents

Abstract

PURPOSE:To prevent the luminance of an X-ray radioscopic image on a TV monitor from rising excessively even if an X-ray collimator is inserted, in the case of executing X-ray radioscopic photographing by using an automatic TV luminance adjusting mechanism. CONSTITUTION:The system is provided with an IBS signal generator 12 corresponding to two large and small areas A1, A2 in a screen on a TV monitor 8, another IBS signal generator 12 corresponding to a screen area BLK projected in a black level by inserting an X-ray collimator 3', and a selecting circuit 9 in which an IBS signal of this black level is compared with a set value and by its result, one of other IBS signals is fed back.

Description

Detailed Description of the Invention [Industrial applications]

The invention is used in the field of medical radiography. The present invention relates to an X-ray fluoroscopy system, and more particularly to an image intensifier (II) and a television (T).
The present invention relates to an X-ray TV fluoroscopic imaging apparatus including a V) system, and particularly to an improved automatic adjustment of the X-ray fluoroscopic image brightness when an X-ray collimator is inserted.

[Prior Art]

Conventionally, a mechanism for automatically adjusting the brightness of an X-ray fluoroscopic image has been incorporated into an X-ray fluoroscopic imaging system including an image intensifier (II) and a television (TV) system. This is a control mechanism that keeps the average brightness or the maximum brightness in the region of interest on the TV monitor constant.

More specifically, referring to FIG.
The X-rays emitted from the ray tube 3 pass through the subject 4 and then
I. I. It is converted to visible light at 6 and this visible output image is displayed on the TV.
Although it becomes a TV image signal through the camera 7 and the camera control unit 11 and is displayed on the TV monitor 8,
The camera control unit 11 has a detection circuit 12 for the TV signal in the region of interest of the TV monitor 8 and sends a TV signal proportional to the average value or the maximum value in the region to the fluoroscopic control device 1, where the TV signal is detected. X-ray control is performed so that the signal becomes constant, that is, the average brightness or maximum brightness of the region of interest of the TV monitor 8 becomes constant.

[Problems to be Solved by the Invention]

However, in such a TV brightness or fluoroscopic image brightness automatic adjustment mechanism, it is determined that the subject has become thick during X-ray fluoroscopy when an observation range is made small by inserting an X-ray collimator, and the X-ray is detected. Since the conditions are set, the X-ray dose increases, the image becomes brighter, the interpretation is difficult, and the diagnosis becomes difficult. In addition, in such a fluoroscopy, the X-ray of the subject
The radiation dose is increasing more than necessary.

An object of the present invention is to prevent the brightness of the fluoroscopic image on the TV monitor from rising excessively even when an X-ray collimator is inserted and fluoroscopic imaging is performed, so that a stable image can be obtained. An object of the present invention is to provide an X-ray fluoroscopic imaging system.

[Means for Solving the Problems]

The above-mentioned object is composed of an image intensifier (I.I.) and a television (TV) system, and an X-ray fluoroscopic image is an I.I. I. Camera control so that the region of interest of the image is observed with a constant brightness when the image is input to the TV monitor and the output image is displayed on the TV monitor as a TV image signal through the TV camera and the camera control unit. Average value of video signal or video brightness control (IBS) in the region of interest in the unit
In an X-ray fluoroscopic imaging system that includes an IBS signal generation circuit that detects a signal and controls the X-ray condition by feeding back the detection signal, at least two of a large area and a small area of the screen on the TV monitor are included. At least two IBS signal generating circuits corresponding to the region of interest;
Another IBS signal generation circuit corresponding to the screen area detected at the black level by inserting the X-ray collimator and the IBS signal at the black level are compared with a set value, and one of the other IBS signals is selected depending on the result. It is achieved by including a selection circuit for feeding back one.

[Action]

The screen area for detecting the average value is divided into a large area and a small area.
And the screen area detected at the black level by inserting the X-ray collimator. IBS signal generation circuits corresponding to these three areas are provided. Therefore, by considering the level degree of the black level IBS signal, it is selected whether the IBS signal of the previous average value detection area is large or small. The conventional problem that the brightness increases when the collimator is inserted or the split mask is inserted is solved. Further, for this reason, an external mechanism for feeding back the operations of the collimator and the division mask is not necessary.

【Example】

A preferred embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows an example in which three types of brightness detection areas are set on the TV monitor screen 8a according to the present invention. A1 is an area for detecting the average brightness of the entire brightness of the fluoroscopic image. A2 is an area for detecting the average brightness of the brightness of the central portion of the perspective image. BLK is an area for detecting the average brightness at a position where it is expected to become dark when a vertical or horizontal collimator is inserted, and a position where it is difficult for the stomach to hit during a gastric barium test is preferable.

FIG. 1 is an overall structural circuit diagram showing one embodiment of the present invention. The automatic adjustment mechanism of the brightness of the X-ray fluoroscopic image according to the conventional example is as described above with reference to this drawing, and in the present invention, the three IBS signals corresponding to the three detection areas shown above in the TV camera control unit 11 are provided. It differs from the conventional example in that a generator 12 is provided and a selection circuit 9 is inserted. Since the present invention relates to the X-ray fluoroscopic imaging system in the case where the X-ray collimator 3'is inserted, the X-ray collimator 3'is shown as it is and can be released upward.

FIG. 3 illustrates a selection circuit according to the present invention. The IBS signal A1 or IBS signal A2 is selected according to the level of the IBS signal BLK. In this exemplary circuit, when the X-ray collimator 3'is inserted and the IBS signal BLK becomes dark, the brightness of the central portion, that is, the IBS signal A2 is switched to control the X-ray condition.

In FIG. 3, ref is a reference value setting device, 9a is a comparator, 9b is an inverter, and 9c is an analog switch, and the IBS signal A2 is selected when the IBS signal BLK becomes equal to or lower than the set reference value. Further, 2 is a high voltage generator, and 10 is a photographing control device.

Further, it is conceivable to provide two or more small areas on the screen to generate IBS signals corresponding to these areas, that is, to set and control a larger number of gates.

【effect】

When the collimator is inserted, the X-ray dose is lowered, and the image is always stable in brightness so that the diagnostic ability is improved.

It is only necessary to incorporate the additional IBS signal generator and the selection circuit according to the present invention only in the X-ray television apparatus, which makes it possible to stabilize the brightness of the fluoroscopic image. It is not necessary to change the fluoroscopic table and the X-ray generator.

It is possible to set the lighting position and size while looking at the monitor, which is easier than the Photomar lighting system.

[Brief description of drawings]

FIG. 1 is an overall configuration block diagram showing an embodiment of the present invention.

FIG. 2 is an exemplary diagram of setting a region of interest on a TV monitor according to the present invention.

FIG. 3 is an exemplary diagram of a selection circuit for selecting one from a plurality of IBS signals according to the present invention.

[Explanation of symbols]

 3'X-ray collimator 6 Image intensifier (II) 7 TV camera 8 TV monitor 9 Selection circuit 11 Camera control unit 12 IBS signal generator A1 Large area on screen A2 Small area on screen BLK X-ray collimator Black level detection area during insertion

Claims (1)

[Claims] 1. An image intensifier (I.
I. ) And a television (TV) system, the X-ray fluoroscopic image is an I.D. I. Camera control so that the region of interest of the image is observed with a constant brightness when the image is input to the TV monitor and the output image is displayed on the TV monitor as a TV image signal through the TV camera and the camera control unit. An X-ray fluoroscopic imaging system in which an IBS signal generation circuit for detecting an average value of video signals or an image brightness control (IBS) signal in the region of interest is provided in the unit and the X-ray condition is controlled by feeding back the detection signal. In, at least two IBS signal generation circuits corresponding to at least two regions of interest on the TV monitor, which are a large area and a small area, and a screen area detected at a black level by inserting an X-ray collimator Another IBS signal generation circuit and the black level IBS signal are compared with a set value, and the result is compared. More other IB
An X-ray fluoroscopic imaging system, comprising: a selection circuit for feeding back one of the S signals.