Visual stimulation increases technetium-99m-HMPAO distribution in human visual cortex.
The ability of changes in the distribution of technetium-99m-hexamethylpropylene amine oxime (99mTc-HMPAO) to reflect physiologic changes in regional cerebral blood flow (rCBF) was evaluated using photic stimulation, a procedure known to increase rCBF in the striate cortex. Seven healthy subjects were injected with 740 MBq 99mTc-HMPAO on two separate days. On one day, the injection was performed following closure of the eyes and patching for 5 min. On the other day, subjects were exposed to a stroboscopic light to produce photic simulation. Images of distribution of 99mTc-HMPAO were obtained using a Strichman 810X single-photon emission computed tomogram (SPECT) brain scanner. Comparison of images obtained during light occluded versus stimulation conditions revealed a significant increase in distribution of radiopharmaceutical in visual cortex relative to whole brain (peak increase corrected for radiopharmaceutical backdiffusion 36.7% +/- 6.6%). HMPAO appears to provide a useful method for detecting relative rCBF increases with SPECT.
Woods
S W
SW
Yale University Department of Psychiatry, New Haven, Connecticut 06519.
Hegeman
I M
IM
Zubal
I G
IG
Krystal
J H
JH
Koster
K
K
Smith
E O
EO
Heninger
G R
GR
Hoffer
P B
PB
D000328:Adult; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D010091:Oximes / Q000493:pharmacokinetics*; D010775:Photic Stimulation; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon; D014793:Visual Cortex / Q000000981:diagnostic imaging* / Q000378:metabolism
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime