ARRT Fluoroscopy and Special Procedures 1 — Questions and Answers
Question 1: What is the primary advantage of fluoroscopy over static radiography?
- It produces images with higher spatial resolution
- It allows real-time dynamic visualization of structures and motion (Correct answer)
- It uses less ionizing radiation than a single radiograph
- It eliminates the need for contrast media
Correct answer: It allows real-time dynamic visualization of structures and motion
Fluoroscopy provides continuous real-time imaging, allowing the radiologist to observe dynamic processes such as swallowing, bowel peristalsis, and contrast flow.
Question 2: During a barium swallow examination, which position best demonstrates a posterior esophageal impression or defect?
- AP projection
- Lateral projection
- RAO projection (Correct answer)
- PA projection
Correct answer: RAO projection
The RAO (right anterior oblique) position places the esophagus between the spine and the heart, providing an unobstructed view of the esophageal lumen.
Question 3: Which type of contrast agent is routinely used for a double-contrast barium enema?
- Iodinated water-soluble contrast
- High-density barium sulfate suspension
- Gadolinium-based contrast
- Low-density barium sulfate with air (Correct answer)
Correct answer: Low-density barium sulfate with air
Double-contrast barium enema uses low-density (thin) barium to coat the mucosal surface combined with air insufflation to distend the colon and reveal fine mucosal detail.
Question 4: Which fluoroscopic technique most effectively reduces patient entrance skin dose during a procedure?
- Increasing the kVp and using last image hold instead of continuous fluoroscopy (Correct answer)
- Decreasing SID to increase beam intensity
- Keeping the image intensifier as far from the patient as possible
- Using continuous fluoroscopy rather than pulsed fluoroscopy
Correct answer: Increasing the kVp and using last image hold instead of continuous fluoroscopy
Higher kVp reduces dose per image, and using last image hold (LIH) eliminates unnecessary continuous fluoroscopy, significantly reducing cumulative skin exposure.
Question 5: What is the primary function of the image intensifier (II) in a fluoroscopic unit?
- To collimate the X-ray beam to the field of interest
- To convert X-ray energy to a bright visible light image for viewing (Correct answer)
- To digitize analog images for PACS storage
- To filter low-energy scatter radiation before it reaches the detector
Correct answer: To convert X-ray energy to a bright visible light image for viewing
The image intensifier converts X-ray photons into electrons, accelerates them, and reconverts them to a bright visible-light image, enabling real-time observation at low dose rates.
Question 6: Which fluoroscopic procedure is specifically designed to evaluate the swallowing mechanism and detect aspiration?
- Upper GI series
- Modified barium swallow (videofluoroscopic swallow study) (Correct answer)
- Barium enema
- Esophagram with double contrast
Correct answer: Modified barium swallow (videofluoroscopic swallow study)
The modified barium swallow (videofluoroscopic swallow study) is performed with a speech-language pathologist to assess oropharyngeal swallowing function and detect aspiration.
Question 7: What is the primary purpose of obtaining a scout (KUB) radiograph before administering contrast for a fluoroscopic GI study?
- To verify the patient's identity against their wristband
- To assess existing pathology, bowel preparation adequacy, and set technique factors (Correct answer)
- To confirm the fluoroscopy unit is properly calibrated
- To pre-expose the image receptor and improve subsequent image quality
Correct answer: To assess existing pathology, bowel preparation adequacy, and set technique factors
A scout image documents baseline anatomy, confirms adequate bowel preparation, reveals pre-existing calcifications or pathology, and guides the subsequent contrast study.
ARRT Fluoroscopy and Special Procedures 1
What is the primary advantage of fluoroscopy over static radiography?