Centre for Advanced MRI seminar: Phenotyping brain blood vessels using dynamic contrast MRI

Friday, 4 May 2012
11:30 a.m. - 12:30 p.m.

Location: At Seminar Room 503-028, Building 503, 85 Park Road, Grafton

Speaker: Dr. Bill Rooney, Senior Scientist and Director Advanced Imaging Research Center Oregon Health & Science University
Department: Centre for Advanced MRI

Although inherent contrast is excellent in MRI, contrast agents are utilized in an estimated 30-40% of all clinical MRI studies, most commonly to improve lesion conspicuity. Dynamic contrast MRI techniques collect a time series of images before and after contrast administration and model the tissue response function to produce parametric maps of tissue physiology.

These maps have been very informative for research studies and are finding increased application in the clinic. Unlike nuclear medicine tracers, MRI contrast agents are not detected directly – MRI detects the agent indirectly through the extent that the 1H2O signal is perturbed. The indirect nature of MRI contrast agent detection provides an opportunity to investigate tissue inter-compartmental water exchange using MRI variants of classic NMR techniques.

This seminar will focus on MRI methods to map tissue properties including blood volume, blood vessel permeability, equilibrium water molecular exchange across the blood-brain-barrier (BBB). In the normal brain, the trans-BBB permeability coefficients for 1H2O and  contrast agents differ by four orders of magnitude (or more), and each is related to a different aspect of small vessel physiology. Examples from normal brain, multiple sclerosis, and brain tumors will be presented.