Predicting vascular diseases using MRI
Predicting stroke and other vascular diseases using high-resolution MRI
Our understanding of the biology of vascular disease is quickly moving away from a simplistic model based on luminal stenosis. We have learned that vessels are not simple conduits. They are complex dynamic organs that have downstream effects on end-organ pathobiology. A commonly used model for the study of disease has been based on endarterectomy specimens. This approach has significantly added to our knowledge of atherosclerosis. However, histological specimens can only give a snap shot at one moment in time. Usually, a patient undergoes surgical procedure once the extent of disease is severe, so only one part of the spectrum of disease is available for analysis.
MRI can image the vessel wall with high-resolution. It can also extract multiple tissue characteristics. Recent technical developments have allowed our group to acquire images of the carotid vessel wall in vivo at high spatial resolution (0.5 mm isotropic), allowing accurate detection and localization. This lets us correlate imaging with different features from post-operative surgical specimens.
One characteristic that is of great interest and is easily detectable by MRI is intraplaque hemorrhage (IPH). Our group and others around the world have shown that patients with MRI-detected IPH have a worse prognosis than those patients who do not have IPH.
Very little evidence exists relating IPH directly with the development of end-organ disease such as stroke. Therefore, we aim to characterize carotid plaque morphology using high-resolution MRI and monitor future clinical outcomes. With improved disease stratification, we may be able to more accurately identify patients who would benefit from targeted therapies with the aim of reducing brain disease burden.