Clinical Procedures
Core concepts
Clinical procedures questions test whether you can select and execute routine and specialty exams safely and reproducibly. Know the standard projections and patient positioning for common studies, the rationale for each position, and the patient preparation required (fasting, bowel prep, hydration, medication holds). Understand contrast media categories-iodinated (ionic vs nonionic), barium, and gadolinium-and their routes: oral, intravenous, intrathecal, and rectal. Match the study to the route and to the contraindication profile.
Traps in questions
Watch for absolute versus relative contraindications. Pregnancy is a relative concern for most diagnostic x-ray but a strong consideration for abdominal/pelvic exposure; gadolinium avoidance in significant renal impairment reflects nephrogenic systemic fibrosis risk. Metformin and iodinated contrast is a labeled concern tied to renal function-know that guidance hinges on kidney status, not a blanket rule. Distinguish a barium study from a water-soluble contrast study when perforation is suspected. Do not confuse patient preparation for a study with post-procedure care.
Technique and safety
Immobilization, shielding where appropriate, and clear breathing instructions improve quality and reduce repeats. Confirm patient identity and the ordered exam before starting, and verify that the correct laterality is marked when relevant.
Worked rule of thumb
When a question asks which contrast to use, ask two questions: what is the route, and what is the contraindication? Suspected bowel perforation points to water-soluble contrast, not barium.