Digital radiography apparatus

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.

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.

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.