MRI MRI Contrast Agents 2

Question 1

Gadolinium retention in the brain has been observed particularly in which structure on unenhanced T1-weighted images in patients receiving multiple GBCA doses?

Accepted Answer

Dentate nucleus of the cerebellum

Answer

Hippocampus

Answer

Thalamus

Answer

Caudate nucleus

Question 2

Which of the following best describes a blood-pool GBCA used in MR angiography?

Accepted Answer

It binds reversibly to albumin, prolonging intravascular residence time

Answer

It remains exclusively in the arterial system

Answer

It distributes only in hepatic tissue

Answer

It crosses the blood-brain barrier

Question 3

For a contrast-enhanced MRA of the aorta, the bolus tracking technique monitors contrast arrival in which vessel to trigger the 3D acquisition?

Accepted Answer

Abdominal aorta or descending thoracic aorta at the level of interest

Answer

Superior mesenteric artery

Answer

Right atrium

Answer

Femoral artery

Question 4

Which of the following is the correct management for a patient who experiences an acute severe allergic-like reaction (anaphylaxis) following GBCA injection?

Accepted Answer

Stop contrast injection, call code team, administer epinephrine 0.3 mg IM (1:1000)

Answer

Administer oral Benadryl and observe for 15 minutes

Answer

Administer 50 mg IV diphenhydramine and continue scan

Answer

Administer IV saline bolus only

Question 5

What is the primary advantage of using a higher-relaxivity GBCA (e.g., gadobenate dimeglumine) compared to a standard-relaxivity agent?

Accepted Answer

It can be used at a lower dose to achieve comparable enhancement

Answer

It is completely renally safe at any dose

Answer

It eliminates the need for dynamic imaging

Answer

It crosses the blood-brain barrier more readily

Question 6

The term 'T1 mapping' in cardiac MRI using gadolinium is used to quantify which clinically important tissue property?

Accepted Answer

Extracellular volume fraction (ECV) as a marker of fibrosis

Answer

Myocardial perfusion rate

Answer

Ejection fraction

Answer

Coronary artery stenosis grade