Quantitation of rCBF by 99mTc-Hexamethylpropyleneamine Oxime Single Photon Emission Computed Tomography Combined with 133Xe CBF

A simple, noninvasive method of measuring CBF that uses single photon emission computed tomography (SPECT) of 99m Tc-hexamethylpropyleneamine oxime ( 99m Tc-HMPAO) and whole-brain CBF obtained by 133 Xe clearance technique was developed. SPECT data were normalized to the count density of HMPAO uptake in the whole brain and then converted to the absolute units of CBF by multiplying average CBF in the whole brain obtained by 133 Xe. Mean CBF values in healthy volunteers (n = 12) were 49 ± 7 and 30 ± 5 ml 100 g −1 min −1 for gray matter and white matter, respectively, with a global flow value of 45 ± 5 ml 100 g −1 min −1 . The mean flow value was 19 ± 7 ml 100g −1 min −1 for the core of the infarct and 31 ± 5 ml 100 g −1 min −1 for the contralateral region (n = 13). CBF values were reproducible for all brain regions. The method was convenient to use and suitable for the routine measurement of regional CBF in normal and pathologic states.