Mouse lumbar and cervical spinal cord blood flow measurements by arterial spin labeling: sensitivity optimization and first application.

In spinal cord injuries (SCI), tissue edema and consequent ischemia play an important role in neuronal damage. The assessment of quantitative spinal cord blood flow (SCBF) would be very valuable to help in understanding SCI pathophysiology. SCBF has previously been measured in animals with invasive techniques such as hydrogen clearance or labeled microspheres. A recent preliminary study also demonstrated the feasibility of assessing cervical SCBF by MRI with arterial spin labeling (ASL). However, due to bulk motion and field inhomogeneities, the feasibility of perfusion MRI at lower levels of the SC (thoracic, lumbar) remained an open question. In the present study, absolute SCBF measurements were carried out at both the cervical C3 and lumbar L1 levels of mouse SC using an adapted presaturated flow-sensitive alternating inversion recovery (presat-FAIR) ASL technique at 11.75T. Quantitative SCBF maps (resolution of 133 x 133 microm(2)) showed significantly lower gray matter (GM) perfusion values at the L1 level as compared to the C3 level (6% and 11% for the ventral and dorsal horns and 8% for total GM). The presat-FAIR technique was then successfully applied to a mouse model of hemisection performed at the L1 level, illustrating the potential of ASL to help in SC pathology characterization. (c) 2009 Wiley-Liss, Inc.