Comparison of Transvascular Water Exchange Between Mannitol and CO2 Challenges

¹Health Science and Technology, MIT, Cambridge, MA, USA; ²Martinos Center for Biomedical Imaging, MGH, Charlestown, MA, USA; ³Medical School, University of Massachusetts, Worcester, MA, USA

Previous studies have shown that trans-vascular water movement (i.e. intra-/extra-vascular water exchange rate: WER) and cerebral blood volume (CBV) can be quantified using a 3D spoiled gradient echo and a long-circulating intravascular contrast agent (Gd-PGC). In the current study, we used two well-known cerebrovascular perturbations, i.e. intravenous Mannitol injection and CO2 challenges (1) to show that CBV and WER can be simultaneously and independently measured and (2) investigate the possible mechanistic differences between the two challenges.