Atherosclerosis is the accumulation of plaque within a blood vessel wall and accounts for 20% of deaths in Canada. Atherosclerotic lesions are evaluated in terms of morphology, degree of stenosis, composition, and dynamics. Plaques with large lipid cores and thin fibrous caps are more likely to cause cardiovascular events.
The bifurcation of the carotid artery is particularly susceptible to plaque accumulation due to the complicated hemodynamics in the region. The carotid arteries supply blood to the brain, and atherosclerosis of the carotid arteries is linked to stroke risk. Decreases in carotid arterial distension are associated with both plaque growth and rupture. As such, the characterization of carotid distensibility is an important part of stroke prevention.
Imaging modalities capable of measuring distensibility are ultrasound, computed tomography and bright blood magnetic resonance imaging. However, these techniques do not provide compositional information. In this thesis I present and successfully demonstrate a retrospectively gated black blood fast spin echo MR imaging technique to capture the motion of the carotid arterial wall over the cardiac cycle. The sequence was validated in digital phantoms and tested for functionality, accuracy and repeatability in volunteers. Distensibility measures obtained from these images were found to be within the normal range for volunteers of this age group. The blood-wall contrast and temporal information obtained with the dynamic fast spin echo sequence show potential for clinical application in the evaluation of the distensibility of atherosclerotic carotid arteries.