Young Ro Kim1, Guangping Dai1, Shuning Huang1,2, Peter Caravan1, Alexei Bogdanov3, Bruce Ro Rosen1
1Athinoula Martinos Center for Biomedical Imaging/ Massachusetts General Hospital, Charlestown, MA, USA; 2Health Science and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA; 3University of Massachusetts School of Medicine, Worcester, MA, USA
We have developed a novel MRI scheme with corrections for T2* signal contribution for quantifying relative transvascular water exchange rate (WER) across non-leaky vascular membranes (i.e., BBB) and absolute cerebral blood volume (CBV), irrespective of the time-dependence of systemic contrast agent (e.g., Gd-DTPA: MW ~500 Da) concentration. Using normal wild type mouse models, we compared regional WER and CBV (cortex vs. striatum) determined by the typical macromolecular approach (Gd-PGC: MW ~500,000 Da) with the results acquired with the proposed method using the widely available Gd-DTPA. Despite the severe time dependence of the blood Gd-DTPA concentration, the measured CBV and WER were similar to those quantified by the traditional macromolecular method.
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