Radiography Exam Contrast Media and Pharmacology

Question 1

Which class of iodinated contrast media has the lowest osmolality and is considered safest for intravascular administration, especially in high-risk patients?

Accepted Answer

Nonionic iso-osmolar contrast media

Answer

Nonionic iso-osmolar contrast agents (e.g., iodixanol) have an osmolality equal to blood (~290 mOsm/kg) and are associated with the lowest risk of adverse reactions.

Question 2

A patient receiving iodinated IV contrast suddenly develops generalized urticaria, bronchospasm, and hypotension. This reaction is classified as:

Accepted Answer

Anaphylactoid (anaphylaxis-like) reaction

Answer

Generalized urticaria combined with bronchospasm and hypotension constitutes a severe anaphylactoid reaction, which requires immediate emergency treatment with epinephrine.

Question 3

The most important risk factor for contrast-induced acute kidney injury (CI-AKI) following IV iodinated contrast administration is:

Accepted Answer

Pre-existing renal insufficiency (elevated serum creatinine/reduced eGFR)

Answer

Pre-existing renal insufficiency (eGFR <30–45 mL/min/1.73m²) is the most significant risk factor for contrast-induced acute kidney injury.

Question 4

Barium sulfate is the preferred contrast agent for gastrointestinal studies when aspiration is NOT a concern because:

Accepted Answer

It provides superior mucosal coating and image quality compared to water-soluble agents

Answer

Barium sulfate provides excellent mucosal coating for double-contrast GI studies, giving superior visualization of the mucosal surface compared to water-soluble contrast.

Question 5

Which route of contrast administration requires the highest iodine concentration for adequate opacification in CT imaging?

Accepted Answer

Intravenous (IV) injection

Answer

IV contrast requires high iodine concentration (e.g., 300–370 mgI/mL) because it is diluted by blood volume before reaching target tissues; oral and intrathecal contrast use much lower concentrations.

Radiography Exam Practice Test

Radiography Exam Practice Test

Radiography Exam Contrast Media and Pharmacology