Monitoring relative diameter change of the carotid artery using non-contrast-enhanced 4D dynamic angiography: preliminary results

Motivation: The carotid artery anatomy is routinely studied with MRI, whilst its relative diameter change is evaluated using ultrasound. An MRI technique to measure the carotid diameter change throughout the cardiac cycle could therefore be complementary to the existing toolset. Goal(s): To combine carotid MR angiography and diameter change quantification in one scan without contrast agent injection. Approach: A 4D (3D+time) free-running sequence was extended with slab-selective RF pulses to increase the inflow blood-to-muscle contrast. Carotid diameter changes and contrast ratios were quantified. Results: The contrast ratio significantly improved with the use of slab-selective pulses and the carotid relative diameter change was precisely measured. Impact: 4D free-running MR angiography with slab-selective RF pulses allows for the dynamic visualization of the carotid lumen and the quantification of the relative carotid diameter change throughout the cardiac cycle without contrast agent injection.