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Cerebrovascular disease is one of the leading causes of death, and approximately 50% of survivors have a residual
neurologic deficit and greater than 25% require chronic care. Cerebrovascular reserve capacity (CVRC) describes how
far cerebral perfusion can increase from a baseline value after stimulation. High blood pressure is the most important
independent risk factor for stroke and other vascular diseases. The incidence of stroke in the hypertensive is six times
higher than in the patient with normal blood pressure. CVRC in the hypertensive was even lower than in control patients.
MR perfusion weighted imaging (MR PWI) with the well-established acetazolamide (ACZ) stimulation test has been
used for assessing brain function. The aim of this work is to assess the cerebrovascular reserve capacity by MR PWI with
"ACZ" tolerance test in spontaneous hypertensive rat (SHR) and to identify its value in evaluating the CVRC.
Experimental animal including 3 groups: Wistar-Kyoto rats (WKY) (12-week-old) as control group, SHR (12-week-old
and 20-week-old) as experimental group. MR PWI was performed respectively before and after acetazolamide
administrated orally in 3 groups on a clinical 1.5 Tesla GE Signa MR fx/i whole-body MR system. The ROI was chosen
in the bilateral frontal lobe to measure the value of rCBV, rCBF and MTT. The results showed that before ACZ-test,
there was statistic differences between the WKY and SHR(12-week-old), and between SHR(12-week-old) and
SHR(20-week-old) in the values of rCBV and rCBF (P>0.05), and after ACZ-test, there were statistic differences
between WKY and SHR (20-week-old), and between SHR(12-week-old) and SHR(20-week-old) in the rCBV value (P<0.05). It is concluded that the method of MRI PWI combined with the "ACZ stress test" can provide more qualitative
and half-quantitative information on the cerebral perfusion to evaluate the CVRC in SHR.
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