Medical Physics Seminar – Monday, March 5, 2012
MR Imaging of Neurovascular Disease
Timothy J. Carroll, Ph.D. (guest of Dr. Oliver Wieben)
MR Imaging of Neurovascular Disease, Associate Professor of Biomedical Engineering, Director of MRI Research, Department of Radiology, Northwestern University
With the recent results from both SAMMPRIS and DEFUSE II, there is a renewed interest in quick, non-invasive means of assessing both acute stroke and chronic conditions such as intracranial atherosclerotic disease (ICAD). Over the years we have learn much about the role that altered hemodynamics play in predicting ischemic stroke through the study of carotid artery disease. NASCET criteria for the evaluation of carotid stenosis grade has been supplemented by the quantification of hemodynamic failure with PET images and novel approaches to vascular wall imaging. However, less attention has been paid to the understanding and quantification of hemodynamic failure with MRI, particularly in ICAD, which accounts for 70% of all strokes worldwide. We will report on our attempts to mimic the groundbreaking work done using positron emission tomography with standard 1.5 T and 3.0T MRI scanners with “off the shelf†contrast agents. Our goal is to develop a series of MRI pulse sequences that are capable of determining the stages of hemodynamic failure proposed by Derdeyn as a diagnostic tool that predicts the risk of stroke. Of primary importance is the fast-user independent image generation to facilitate these technologies as broadly as possible. We will discuss the development, validation and clinical implementation of these sequences, that, can provide the “one stop shop†for comprehensive evaluation of compromised neurovascular capacity in this high risk patients.