Fluoroscopy and Interventional Procedures Flashcards

What is the primary function of the image intensifier in a fluoroscopic system?

Answer: To amplify and convert X-ray energy into a brightened visible image, reducing patient dose

The image intensifier converts X-ray photons to visible light and electronically amplifies the signal, producing a bright enough image for real-time viewing while significantly reducing patient dose compared to older fluoroscopic methods.

Per FDA regulations (21 CFR 1020.32), what is the maximum air kerma rate at the reference point for standard fluoroscopic systems?

Answer: 88 mGy/min

FDA regulations cap the air kerma rate at 88 mGy/min (10 R/min) at the reference point for standard fluoroscopic units to limit entrance skin dose during procedures.

What is the primary advantage of pulsed fluoroscopy over continuous fluoroscopy?

Answer: Reduced patient radiation dose

Pulsed fluoroscopy delivers X-rays in brief discrete bursts rather than continuously, substantially lowering the total radiation dose to the patient while maintaining diagnostic image quality.

What does the 'last image hold' (LIH) feature do in a fluoroscopic system?

Answer: Displays the final fluoroscopic frame as a static image after the beam is turned off

Last image hold freezes the last acquired fluoroscopic frame on the monitor as a static image when the foot pedal is released, allowing the radiologist to review anatomy without continuing to irradiate the patient.

What is the primary purpose of automatic brightness control (ABC) in fluoroscopy?

Answer: To automatically adjust technical factors to maintain consistent image brightness as beam penetration changes

ABC continuously monitors image brightness and automatically adjusts kVp, mA, or both to compensate for varying tissue densities, ensuring consistent image quality throughout the examination.

What is the minimum source-to-skin distance (SSD) required for fixed fluoroscopic equipment per FDA regulations?

Answer: 38 cm (15 inches)

FDA regulations mandate a minimum SSD of 38 cm (15 inches) for fixed fluoroscopic units to limit entrance skin dose by ensuring adequate distance between the X-ray tube and the patient's skin.

What is the primary purpose of spot imaging during a fluoroscopic examination?

Answer: To record selected high-quality static images of specific anatomy or pathology for documentation

Spot imaging captures permanent high-resolution static radiographic frames of areas of interest identified during real-time fluoroscopy, providing diagnostic-quality images for the final report.