JPH0723938A - Digital blood vessel photographing device - Google Patents

Abstract

PURPOSE:To eliminate labor of selecting a reference image by a diagnosing person, enable the next inspection photographing immediately after completion of the first inspection photographing, and improve operability and inspection efficiency by automatically selecting and memorizing a reference image based on a contrast media injection starting time at the time of a first inspection photographing. CONSTITUTION:A device is provided with a contrast media injection starting time detection device 10 to detect a contrast media injection starting time in inspection photographing, and a reference image taking control device 11 to store an image photographed after the elapse of a preliminarily set time or after detection of a preliminarily determined phase of an electrocardiographic waveform after the contrast media injection starting timing in a storage device 7 or 12 as a reference image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital angiography apparatus for automatically selecting and storing a reference image based on the start time of injection of a contrast medium.

[0002]

2. Description of the Related Art Conventionally, in an examination using a digital angiography apparatus, a catheter is inserted and a photographing position is determined by a fluoroscopic image, and after injection of a contrast agent, X-rays are irradiated and several tens of frames are photographed. Shooting the frame is called inspection shooting). These fluoroscopic / photographing operations were repeated several times. During the repeated fluoroscopy / imaging, the diagnostician was asked to percutaneous transluminal coronary angioplasty.
y Angioplasty; hereinafter abbreviated as PTCA), then PTC
To compare the images before and after A, or to display the previously captured image again during inspection, to search for the necessary image, all frames are taken after each inspection One image representative of all frames was selected from among the observed images, and it was used as a reference image.

[0003]

In the above-described conventional digital angiography apparatus, the diagnostician must determine the reference image from all the frames every time one examination radiography is completed, and the rapid processing is required. -In the angiographic examination requiring manipulation, there was a problem that the examination efficiency was reduced.

An object of the present invention is to automatically select and store a reference image based on the start time of injection of a contrast agent at the time of one examination radiography, so that the next image is immediately obtained after the end of one examination radiography. It is an object of the present invention to provide a digital blood vessel photographing apparatus capable of performing examination photographing.

[0005]

The above object is to provide a contrast agent injector for injecting a contrast agent into a subject, a radiation source, and a transmission radiation image which is arranged to face the radiation source with the subject interposed therebetween. A radiation detector for converting a visible light image, a television camera for converting an optical image output from the radiation detector into an electric signal, an A / D converter for converting an output signal of the television camera into a digital signal, and A storage device that stores a digital signal from an A / D converter as image data, a calculation device that reads out image data from the storage device and performs calculation processing, and a digital signal obtained by calculation processing by this calculation device is an analog signal. A digital angiography apparatus comprising a D / A converter for converting into a signal and a display device for displaying an image based on an analog signal from the D / A converter, At the time of imaging, a contrast agent injection start time point detection device for detecting the injection start time point of the contrast agent, and from the contrast agent injection start time point detected by this contrast agent injection start time point detection device, after a lapse of a preset time, or This is achieved by providing a reference image capturing control device that stores the image captured after the predetermined phase of the electrocardiographic waveform as a reference image in the storage device or another storage device different from this. .

[0006]

[Operation] The contrast agent injection start time detection device is
The start point of injection of the contrast agent is detected. The reference image capturing control device stores the image captured as a reference image after a lapse of a preset time from the start of injection of the detected contrast agent or after detection of a predetermined phase of the electrocardiographic waveform. Store in the device.

According to this, since the reference image is automatically selected and stored based on the time when the injection of the contrast agent is started at the time of one inspection photographing, immediately after the completion of one inspection photographing, the next inspection photographing is performed. Therefore, it is possible to perform quick processing and operation even in PTCA and the like.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a digital blood vessel photographing apparatus according to the present invention. In this embodiment, an X-ray tube 1 which is a radiation source and a subject 3 are arranged so as to face the X-ray tube 1 so as to face the X-ray tube 1 and a radiation detector which converts a transmitted X-ray image into a visible light image. Intensifier (hereinafter I.
Abbreviated as I.) 2, a television camera 4 for converting an output optical image from II 2 into an electric signal, an A / D converter 5 and an A / D converter 5 for converting an output signal of the television camera 4 into a digital signal Logarithmic converter 6 for logarithmically converting the signal of FIG. 6, a logarithmic converter 6 or a frame memory 7 (71 to 7n) which is a storage device for storing a signal from an arithmetic unit or a central processing unit described later as image data, and an image from the frame memory 7 An arithmetic unit 8 for reading out data and performing arithmetic processing, a contrast agent injector 9 for injecting a contrast agent into the subject 3, and a contrast agent injection start time point by a pressure change in the catheter before and after the injection of the contrast agent from the contrast agent injector 9. A specific image is selected from the images in the frame memory 7 based on the contrast sensor injection start time detection device for detecting the contrast agent injection time and the contrast agent injection start time from the pressure sensor 10. An image data stored in the reference image capture control device 11 that captures an image as a later-described reference image memory, a reference image memory 12 that stores the reference image selected by the reference image capture control device 11, the frame memory 7 or the reference image memory 12. D / A converter 13 for converting the data into an analog signal, monitor TV 14 which is a display device for displaying an image based on the analog signal from the D / A converter, and X-ray control for controlling the tube voltage, tube current, time, etc. 15, a high-voltage generator 16 controlled by the X-ray controller 15 to operate the X-ray tube 1, an operation console 17 for selecting an imaging mode or an imaging site, or inputting commands such as imaging start or subtraction It is composed of a central processing unit 18 that controls each unit. That.

Next, the operation of the device of the present invention will be described. The X-ray emitted from the X-ray tube 1 passes through the subject 3 and is converted into an optical image by II2. This optical image is taken by the TV camera 4, and the output signal of the TV camera 4 is A /
After D / A conversion is performed by the D converter 5, logarithmic conversion is performed by the logarithmic converter 6. The logarithmically converted signal is directly or calculated by the arithmetic unit 8 and sequentially stored in the frame memory 7 (71 to 7n).

During the examination and imaging, the diagnostician injects the contrast agent into the subject 3 by the contrast agent injector 9. At this time, the pressure change in the catheter is detected by the pressure sensor 10. The pressure sensor 10 regards the sudden change point of the pressure as the contrast agent injection start time point and sends it to the reference image acquisition control device 11. The reference image capturing control device 11 stores the image captured after, for example, 3 seconds after the contrast agent injection start time sent from the pressure sensor 10 in the frame memory 7, based on the contrast agent injection start time, and the reference image Is stored in the reference image memory 12.

The image taken 3 seconds after the start of the injection of the contrast agent is used as the reference image, assuming that the contrast agent spreads to all the blood vessels to be examined about 3 seconds after the injection of the contrast agent. This is because the optimum time is set depending on the examination site, the insertion position of the catheter, and the like.

The reference image is taken in every time the contrast agent is injected (every time when the inspection imaging is performed), and the image signal stored in the frame memory 7 and the reference image memory 12 is D / A converted by the D / A converter 13. After being A / A converted, it is displayed as an image on the monitor television 14.

The central processing unit 18 controls the operation of each of these parts.
Then, the diagnostician inputs necessary commands from the console 17.

In the above embodiment, the pressure sensor 10 is used as the contrast agent injection start time point detecting device for detecting the contrast agent injection start time point, but the invention is not limited to this.
For example, as shown in FIG. 2, instead of the pressure sensor 10, the image stored in the frame memory 7n and the image captured one frame before and stored in the frame memory 7n-1 are subtracted. When there is a difference of a predetermined value or more between the images, the imaging time of the frame memory 7n is sent to the reference image capture control device 11 as the contrast agent injection start time. May be provided. Here, the reason why the subtraction result is required to have a difference equal to or larger than a certain value as a threshold is to prevent the influence of the body movement between the two images.

FIG. 3 shows a configuration example in which an electrocardiograph 30 is provided as means for giving the reference image capture control device 11 a time at which a captured image is captured as a reference image in the reference memory 12 from the start of injection of a contrast agent. . In this example, an electrocardiographic waveform from the subject 3 is input from the electrocardiograph 30 to the reference image acquisition control device 11. FIG. 4 is a time chart showing the control in the reference image capturing control device 11 when the electrocardiograph 30 is used as described above.

As shown in the figure, the time t1 at which the injection of the contrast medium is started
After that (t2), a contrast agent injection start signal is sent by the contrast agent injection start time point detection device 31 to the reference image acquisition control device 11. When receiving the contrast agent injection start signal,
The reference image acquisition control device 11 includes an electrocardiograph 30.
The reference image is an image taken after the detection (t3) of a certain phase (the second peak waveform after receiving the contrast agent injection start signal in FIG. 4) of the electrocardiographic waveform sent from Is stored in the reference memory 12. The optimum phase of the electrocardiographic waveform for capturing the reference image is set depending on the examination site and the like.

Further, in the above-described embodiment, the frame memory 7 and the reference image memory 12 are configured separately and independently, but each memory may be configured to be stored in one memory.

[0018]

As described above, according to the present invention, the diagnostician does not need to observe all the frames to select the reference image at the end of one inspection radiographing, and the next inspection radiographing can be performed immediately. Therefore, there is an effect that operability and inspection efficiency can be improved, and particularly in PTCA and the like, rapid processing and operation are possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a device of the present invention.

FIG. 2 is a block diagram showing another embodiment of the present invention.

FIG. 3 is a block diagram showing another embodiment of the same.

FIG. 4 is a time chart showing how reference images are captured in the embodiment shown in FIG.

[Explanation of symbols]

 1 X-ray tube 2 II (radiation detector) 3 subject 4 TV camera 5 A / D converter 6 logarithmic converter 7 (71 to 7n) frame memory (memory device) 8 arithmetic unit 9 contrast agent injector 10 pressure Sensor (Contrast agent injection start time detection device) 11 Reference image acquisition control device 12 Reference image memory (other storage device) 13 D / A converter 14 Television monitor 15 X-ray controller 16 High voltage generator 17 Operator console 18 Central processing Device 20 Contrast agent injection start time point arithmetic device 30 Electrocardiograph 31 Contrast agent injection start time point detection device

Claims (1)

[Claims] 1. A contrast agent injector for injecting a contrast agent into a subject, a radiation source, and radiation detection which is arranged to face the radiation source with the subject interposed therebetween and converts a transmitted radiation image into a visible light image. Device, a television camera for converting an optical image output from the radiation detector into an electric signal, an A / D converter for converting an output signal of the television camera into a digital signal, and a digital signal from the A / D converter. A storage device that stores a signal as image data, an arithmetic device that reads out image data from the storage device and performs arithmetic processing, and a D / A conversion that converts a digital signal obtained by arithmetic processing by the arithmetic device into an analog signal. In a digital angiography apparatus including a display device and an image display device that displays an image based on an analog signal from the D / A converter,
A contrast agent injection start time point detection device for detecting a contrast agent injection start time point, and a predetermined time after the contrast agent injection start time point detected by the contrast agent injection start time point detection device, or an electrocardiographic waveform After the detection of the predetermined phase of
2. A digital angiography apparatus, comprising: a reference image capturing controller that stores the image captured in step 1 as a reference image in the storage device or another storage device different from the storage device.