RT Journal Article
SR Electronic
T1 Age-Related Changes of Cerebral Autoregulation: New Insights with Quantitative T2′-Mapping and Pulsed Arterial Spin-Labeling MR Imaging
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 2081
OP 2087
DO 10.3174/ajnr.A3138
VO 33
IS 11
A1 M. Wagner
A1 A. Jurcoane
A1 S. Volz
A1 J. Magerkurth
A1 F.E. Zanella
A1 T. Neumann-Haefelin
A1 R. Deichmann
A1 O.C. Singer
A1 E. Hattingen
YR 2012
UL http://www.ajnr.org/content/33/11/2081.abstract
AB BACKGROUND AND PURPOSE: Cerebral perfusion and O2 metabolism are affected by physiologic age-related changes. High-resolution motion-corrected quantitative T2′-imaging and PASL were used to evaluate differences in deoxygenated hemoglobin and CBF of the gray matter between young and elderly healthy subjects. Further combined T2′-imaging and PASL were investigated breathing room air and 100% O2 to evaluate age-related changes in cerebral autoregulation. MATERIALS AND METHODS: Twenty-two healthy volunteers 60–88 years of age were studied. Two scans of high-resolution motion-corrected T2′-imaging and PASL-MR imaging were obtained while subjects were either breathing room air or breathing 100% O2. Manual and automated regions of interest were placed in the cerebral GM to extract values from the corresponding maps. Results were compared with those of a group of young healthy subjects previously scanned with the identical protocol as that used in the present study. RESULTS: There was a significant decrease of cortical CBF (P < .001) and cortical T2′ values (P < .001) between young and elderly healthy subjects. In both groups, T2′ remained unchanged under hyperoxia compared with normoxia. Only in the younger but not in the elderly group could a significant (P = .02) hyperoxic-induced decrease of the CBF be shown. CONCLUSIONS: T2′-mapping and PASL in the cerebral cortex of healthy subjects revealed a significant decrease of deoxygenated hemoglobin and of CBF with age. The constant deoxyHb level breathing 100% O2 compared with normoxia in young and elderly GM suggests an age-appropriate cerebral autoregulation. At the younger age, hyperoxic-induced CBF decrease may protect the brain from hyperoxemia. BOLDblood oxygen level–dependentdeoxyHbdeoxyhemoglobinGMgray matterGM frontoparietalfrontoparietal cortex (automatic ROI)MPRAGEmagnetization-prepared rapid acquisition of gradient echoOEFoxygen extraction fractionPASLpulsed arterial spin-labelingrCBFregional CBF