Increased brain retention of Tc-99m HMPAO following acetazolamide administration.

Sixty-five patients referred for Tc-99m HMPAO SPECT brain perfusion studies had measurements of global Tc-99m HMPAO retention after injection at rest and after acetazolamide pretreatment. Acetazolamide produced relative changes in Tc-99m HMPAO retention similar to those previously reported with Xe-133 regional cerebral blood flow (rCBF) measurements. This addition to imaging protocols allows another objective evaluation of the cerebral vascular reserve.