Digital radiography apparatus

• US 4,903,705 A
• Filed: 10/11/1988
• Issued: 02/27/1990
• Est. Priority Date: 11/09/1984
• Status: Expired due to Fees

• Current Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Original Assignee: Hitachi Medical Corporation (Hitachi, Ltd.)
• Inventors: Kamiya, Masami, Imamura, Kazushi
• Primary Examiner(s): Jaworski, Francis
• Application Number:
  US07/259,426
• Time in Patent Office: 504 Days
• Field of Search: 364/414, 119/653, 119/659, 119/660-661, 358/111, 378/94, 378/95, 378/41-42
• US Class Current: 600/431
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 6/504 for diagnosis of blood vessels, e.g. by angiography
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: H04N 5/3205 using subtraction imaging techniques

Abstract

A device for obtaining an image of a subject including a signal generating device including, for example, an X-ray generator for obtaining a signal representative of the subject, a detecting device for detecting a predetermined phase such as the R-wave of the electrocardiographic waveform of the subject, and an actuating device responsive to the detecting device for actuating the X-ray generator in substantial synchronism with the occurrence of the predetermined phase of the electrocardiographic waveform to thereby obtain the image of the subject. The device may include control circuitry for operating the detecting device, the actuating device and X-ray generator in the foregoing order to obtain a mask image of the subject, a device for storing the mask image, a device for injecting a contrast medium into the subject; a device for repeating the above operation of the detecting device, the actuating device, and the X-ray generator in the foregoing order to obtain a live image of the subject, and a device for subtracting the mask image and the live image with respect to each other to obtain a subtraction image to thereby eliminate motion-artifacts due to heartbeats of the subject, although subtraction angiography need not be employed. Different modes of operation of the device are also disclosed.

Claims

1. A digital radiography apparatus comprising:

electrocardiographic wave detecting means for detecting electrocardiographic waves of a subject before and during an X-ray photographing operation, and means for converting the waveforms of the electrocardiographic waves into signals for display;

contrast medium injection means for injecting contrast medium into a portion of the subject to be photographed with X-rays;

X-ray photographing means for irradiating the subject with X-rays and generating an optical X-ray image of the portion of the subject to be photographed;

means for controlling said contrast medium injection means and said X-ray photographing means and generating images at predetermined times both before and after injection of the contrast medium into the subject;

means for converting the X-ray images before and after injection of the contrast medium into the subject into television signals in time-series;

means for successively converting the television signals to digital signals and performing a subtraction operation between the digital signals before and after injection of the contrast medium into the subject;

display means for displaying a resultant X-ray image obtained through the subtraction operation and the waveform of the electrocardiographic wave detected by said electrocardiographic wave detecting means;

means for inputting a marker on the displayed waveform of the electrocardiographic wave with a cursor; and

means for detecting a specific wave phase in the electrocardiographic wave and setting the timing for the X-ray photographing operation based upon the position of the cursor relative to the position of the specific wave phase.

2. A digital radiographic apparatus comprising:

electrocardiographic wave detecting means for detecting an electrocardiographic wave of a subject and outputting a detection signal in response to detection of a specific wave phase in the electrocardiographic wave;

contrast medium injection means for injecting contrast medium into the portion of the subject to be photographed with X-rays;

means for setting a desired lapse time from an instant in time when a specific wave phase occurs;

X-ray photographing means for irradiating the subject with X-rays and generating an optical X-ray image of the portion of the subject to be photographed;

means for controlling said contrast medium injection means and said X-ray photographing means and generating X-ray images at predetermined times both before and after injection of the contrast medium into the subject;

means for converting the X-ray images before and after injection of the contrast medium into the subject into television signals in time-series;

means for successively converting the time-series television signals into digital signals and performing a subtraction operation between the digital signals before and after injection of the contrast medium into the subject;

display means for displaying a resultant X-ray image obtained through the subtraction operation; and

means for actuating said electrocardiographic wave detecting means in response to a photography starting signal and applying an X-ray radiation instruction signal to said X-ray photographing means when a time elapsing from the occurrence of the detection signal in said electrocardiographic detecting means corresponds to a desired lapse time.

3. A digital radiography apparatus comprising:

electrocardiographic wave detection means for detecting electrocardiographic waves of a subject before and during the X-ray photographing operation and converting the waveforms of the electrocardiographic waves into signals for a display;

contrast medium injection means for injecting contrast medium into a portion of the subject to be photographed with X-rays;

X-ray photographing means for irradiating the subject with X-rays and generating na optical X-ray image of the portion of the subject to be photographed;

means for controlling said contrast medium injection means and said X-ray photographing means, and generating X-ray images both before and after injection of the contrast medium into the subject while X-rays are substantially continuously irradiated;

means for converting the X-ray images before and after injection of the contrast medium into the subject into television signals;

means for successively converting the television signals to digital signals and performing a subtraction operation between the digital signals before and after injection of the contrast medium into the subject;

display means for displaying a resultant X-ray image obtained through the subtraction operation and the waveform of the electrocardiographic wave detected by said electrocardiographic wave detecting means;

meant for inputting a marker on the displayed waveform of the electrocardiographic wave with a cursor;

means for detecting a specific wave phase in the electrocardiographic wave and extracting only the digital signals corresponding to the position of the cursor relative to that of the specific wave phase; and

means for subjecting to the subtraction operation the extracted digital signals before and after injection of the contrast medium into the subject.

4. A digital radiographic apparatus comprising:

electrocardiographic wave detection means for detecting an electrocardiographic wave of a subject, and outputting a detection signal in response to detection of a specific wave phase in the electrocardiographic wave;

contrast medium injection means for injecting contrast medium into a portion of the subject to be photographed with X-rays;

means for setting a desired time lapse from the instant time when the specific wave phase occurs;

X-ray photographing means for irradiating the subject with X-rays, and generating an optical X-ray image of the portion of the subject to be photographed;

means for controlling said contrast medium injection means and said X-ray photographing means, and generating X-ray images both before and after injection of the contrast medium into the subject while X-rays are substantially continuously irradiated;

means for converting the X-ray images before and after injection of the contrast medium into the subject into television signals;

means for successively converting the television signals into digital signals, and performing a subtraction operation between the digital signals before and after injection of the contrast medium into the subject;

display means for displaying a resultant X-ray image obtained through the subtraction operation;

means for actuating said electrocardiographic wave detecting means in response to a photography starting signal, and extracting from the digital signals only the digital signals at the time when a time elapsing from the occurrence of the detection signal in said electrocardiographic detecting means corresponds to a desired lapse time; and

means for subjecting to the subtraction operation the extracted digital signals before and after injection of the contrast medium into the subject.