Radiography Exam Fluoroscopy and Interventional Procedures 2 — Questions and Answers
Question 1: Which contrast medium is most commonly used in a barium enema (lower GI series) procedure?
- Non-ionic iodinated contrast
- Barium sulfate suspension (Correct answer)
- Ionic iodinated contrast
- Carbon dioxide gas alone
Correct answer: Barium sulfate suspension
Barium sulfate suspension is the standard contrast medium for barium enema procedures because it coats the colonic mucosa effectively, is radiopaque, and is safe in an intact bowel.
Question 2: What is the pharmacologic purpose of administering glucagon during a GI fluoroscopic examination?
- To accelerate barium transit through the GI tract
- To prevent allergic reactions to barium sulfate
- To enhance contrast medium absorption into the mucosa
- To reduce peristalsis and decrease bowel motility for improved mucosal coating (Correct answer)
Correct answer: To reduce peristalsis and decrease bowel motility for improved mucosal coating
Glucagon is a hypotonic agent that temporarily suppresses gastrointestinal peristalsis, allowing barium to coat the mucosal surface more uniformly and improving image quality during the examination.
Question 3: During a small bowel follow-through (SBFT), how frequently are radiographs typically obtained after the patient ingests barium?
- Only a single image is taken at 1 hour post-ingestion
- Every 60 minutes for up to 8 hours
- Every 15-30 minutes until barium reaches the terminal ileum (Correct answer)
- Every 5 minutes for the first hour only
Correct answer: Every 15-30 minutes until barium reaches the terminal ileum
Serial radiographs obtained every 15-30 minutes track the progression of barium through the small bowel, with imaging continuing until contrast opacifies the terminal ileum to confirm complete evaluation.
Question 4: What anatomical structures are primarily evaluated during a voiding cystourethrogram (VCUG)?
- The kidneys and collecting system for calculi
- The renal arteries and veins for stenosis
- The bladder and urethra during filling and voiding phases (Correct answer)
- The ureters during peristaltic activity
Correct answer: The bladder and urethra during filling and voiding phases
A VCUG uses fluoroscopy and contrast to evaluate bladder morphology and urethral anatomy during filling and voiding, and is the study of choice for detecting vesicoureteral reflux.
Question 5: How does a double-contrast barium enema differ from a single-contrast barium enema?
- Double-contrast uses two different concentrations of barium suspension
- Double-contrast uses barium and air together to better coat and distend the colon for mucosal surface detail (Correct answer)
- Double-contrast combines barium and iodine contrast simultaneously
- Double-contrast provides better visualization of large polypoid filling defects only
Correct answer: Double-contrast uses barium and air together to better coat and distend the colon for mucosal surface detail
The double-contrast technique uses barium to coat the mucosal lining and insufflated air to distend the colon, providing superior visualization of small polyps and subtle mucosal lesions compared to single-contrast studies.
Question 6: What is the most critical contraindication to performing a barium enema examination?
- Patient allergy to iodinated contrast media
- Recent colonoscopy performed within the last 24 hours
- Suspected perforation of the colon (Correct answer)
- Mild constipation or the presence of fecal material
Correct answer: Suspected perforation of the colon
Suspected bowel perforation is an absolute contraindication because barium escaping into the peritoneal cavity causes barium peritonitis, a life-threatening chemical inflammatory reaction with very high mortality.
Question 7: What is the typical initial patient positioning used when beginning an upper GI series?
- Upright lateral position only
- Prone Trendelenburg position
- Left lateral decubitus position only
- Recumbent position with rotation as directed by the fluoroscopist (Correct answer)
Correct answer: Recumbent position with rotation as directed by the fluoroscopist
The upper GI series typically begins with the patient recumbent, allowing barium to pool and coat the gastric mucosa; the fluoroscopist then rotates the patient as needed to profile different portions of the stomach and duodenum.
Radiography Exam Fluoroscopy and Interventional Procedures 2
Which contrast medium is most commonly used in a barium enema (lower GI series) procedure?