Jr. Petrella et al., AGE-RELATED VASODILATORY RESPONSE TO ACETAZOLAMIDE CHALLENGE IN HEALTHY-ADULTS - A DYNAMIC CONTRAST-ENHANCED MR STUDY, American journal of neuroradiology, 19(1), 1998, pp. 39-44
Citations number
28
Categorie Soggetti
Clinical Neurology","Radiology,Nuclear Medicine & Medical Imaging
PURPOSE: We examined age-related changes in baseline regional cerebral
blood volume (rCBV) and response to acetazolamide stimulation by usin
g dynamic contrast-enhanced MR imaging. METHODS: Thirty healthy volunt
eers ranging widely in age (23 to 82 years) were examined before and a
fter intravenous injection of acetazolamide with dynamic susceptibilit
y contrast-enhanced MR imaging. rCBV values were normalized for inters
ubject and intrasubject comparison by estimating an arterial input fun
ction directly from the imaging data. Preacetazolamide baseline rCBV a
nd the percentage volume change index (PVCI) of the postacetazolamide
to preacetazolamide state were calculated and examined as a function o
f age. RESULTS: Older adults (>50 years) had lower baseline rCBV per u
nit tissue than did younger adults (<50 years), but higher rCBV after
acetazolamide stimulation, Baseline rCBV tended to decrease with age i
n the medial frontal and frontoparietal gray matter regions. Response
to acetazolamide stimulation, measured by PVCI, showed a significant a
ge-related increase in gray matter, approximately 0.5% per year. CONCL
USION: rCBV can be significantly increased after acetazolamide stimula
tion in the healthy aged. These results support the notion that age-re
lated decreases in rCBV measured at rest reflect reduced regional meta
bolic requirements rather than reduced capacity for regional substrate
delivery. These data serve as a normative baseline for comparison stu
dies of rCBV vascular reserve in aging persons with various cerebrovas
cular disorders.