ARRT Fluoroscopy and Special Procedures 2 — Questions and Answers
Question 1: During a hysterosalpingography (HSG), what type of contrast medium is typically used?
- High-density barium sulfate
- Water-soluble iodinated contrast (Correct answer)
- Air only (negative contrast)
- Gadolinium-based contrast agent
Correct answer: Water-soluble iodinated contrast
Water-soluble iodinated contrast is used for HSG because it is absorbed by the peritoneum without residual effect if tubal patency allows spillage into the peritoneal cavity.
Question 2: What serious complication can result from accidental introduction of air into the venous circulation during an IV contrast injection?
- Allergic anaphylaxis
- Venous air embolism (Correct answer)
- Osmotic nephropathy
- Extravasation necrosis
Correct answer: Venous air embolism
Venous air embolism occurs when air enters the venous system and obstructs pulmonary blood flow, which can be life-threatening and requires immediate positioning in the left lateral decubitus (Durant maneuver) position.
Question 3: Which projection during a barium enema best demonstrates the sigmoid colon in its entirety with minimal overlap?
- AP projection
- Lateral projection
- LPO or RPO oblique projection (Correct answer)
- PA projection with caudal angulation
Correct answer: LPO or RPO oblique projection
The LPO or RPO oblique projections rotate the pelvis to uncoil the redundant sigmoid loop and project it away from overlapping loops, providing a clear view of the sigmoid colon.
Question 4: What is the primary purpose of the 'last image hold' (LIH) feature available on modern fluoroscopic equipment?
- To store the final image permanently in PACS
- To display the last acquired fluoroscopic frame so the radiologist can study it without continuing radiation exposure (Correct answer)
- To freeze the table motion during a procedure
- To automatically print the most diagnostically significant frame
Correct answer: To display the last acquired fluoroscopic frame so the radiologist can study it without continuing radiation exposure
Last image hold retains and displays the final fluoroscopic frame on the monitor, allowing the operator to evaluate positioning and anatomy without maintaining continuous radiation exposure.
Question 5: During an upper GI double-contrast examination, what is the primary advantage of the double-contrast technique over single-contrast?
- It eliminates the need for patient preparation
- It reduces examination time significantly
- It provides superior mucosal detail enabling detection of small lesions (Correct answer)
- It lowers the radiation dose to the patient
Correct answer: It provides superior mucosal detail enabling detection of small lesions
Double contrast (high-density barium coating + gas distension) outlines the mucosal surface in fine detail, making small polyps, ulcers, and early gastric carcinoma visible that may be missed on single-contrast studies.
Question 6: What is the pharmacological role of glucagon when administered during a GI fluoroscopic examination?
- It stimulates peristalsis to speed bowel transit
- It produces hypotonic duodenography by temporarily relaxing smooth muscle (Correct answer)
- It neutralizes gastric acid to improve mucosal coating
- It constricts the pyloric sphincter to retain contrast in the stomach
Correct answer: It produces hypotonic duodenography by temporarily relaxing smooth muscle
Glucagon is an antispasmodic agent that temporarily inhibits smooth muscle contraction, reducing peristalsis and allowing better mucosal coating and visualization during hypotonic studies.
Question 7: During a voiding cystourethrogram (VCUG), what critical action is the patient asked to perform at the key phase of the examination?
- Hold their breath during image acquisition
- Actively void (urinate) while images are obtained (Correct answer)
- Perform a Valsalva maneuver to increase intra-abdominal pressure
- Remain completely still in the supine position throughout
Correct answer: Actively void (urinate) while images are obtained
The patient voids (urinates) while fluoroscopic images are obtained to evaluate the urethra, bladder neck function, and detect vesicoureteral reflux during the voiding phase.
ARRT Fluoroscopy and Special Procedures 2
During a hysterosalpingography (HSG), what type of contrast medium is typically used?