Alexander Brost1,
Heiko Schmiedeskamp1, Matus Straka1, Jalal Andre2,
Roland Bammer1
1Center
for Quantitative Neuroimaging, Stanford University, Stanford, CA, United
States; 2Department of Radiology, University of Washington,
Seattle, WA, United States
The spin- and gradient-echo (SAGE) EPI sequence was developed to estimate cerebral blood flow (CBF) and cerebral blood volume (CBV). The main purpose of the sequence is to provide T1-independent perfusion-weighted imaging maps. Gadolinium-based contrast agents cause T1-shortening, in particular, when contrast agent leaks into the extravascular-extracellular space. Leakage correction using SAGE EPI requires a separately acquired pre-bolus T1 map. To estimate the effects of an incorrect T1 map, we simulated the effects using a pharmacokinetic model. Leakage correction could be applied to multi-echo data that lack a properly determined prebolus T1 map without significantly compromising CBV and MTT estimates.
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