Intra-individual differences between technetium-99m-HMPAO and technetium-99m-ECD in the normal medial temporal lobe.
Regional distributions of 99mTc-hexamethyl propyleneamine oxime (99mTc-HMPAO) and 99mTc-ethyl cysteinate dimer (99mTc-ECD) were compared in the normal brain.


METHODS
Six paid, healthy volunteers (mean age 26 yr) had high-resolution neuroperfusion SPECT using both 99mTc-HMPAO and 99mTc-ECD on separate days.


RESULTS
Regional distribution of the two tracers differed. Technetium-99m-HMPAO accumulated more in the thalamus, frontal lobe, temporal lobe and cerebellum than 99mTc-ECD, which accumulated more in the occipital and parietal lobes. There was a considerable difference in the accumulation of the two tracers in the medial temporal lobe. The percent accumulations of 99mTc-HMPAO and 99mTc-ECD in the medial temporal lobe compared with the mean global cerebral cortical accumulation were 93.9% +/- 2.4% and 83.1% +/- 4.1% (mean +/- s.d.), respectively.


CONCLUSIONS
The results suggest that 99mTc-HMPAO and 99mTc-ECD require specific and separate criteria for diagnosing temporal lobe pathologies, such as dementia and temporal lobe epilepsy.
Oku
N
N
First Department of Medicine, Osaka University Medical School, Japan.
Matsumoto
M
M
Hashikawa
K
K
Moriwaki
H
H
Ishida
M
M
Seike
Y
Y
Terakawa
H
H
Watanabe
Y
Y
Uehara
T
T
Nishimura
T
T
D000328:Adult; D002531:Cerebellum / Q000000981:diagnostic imaging; D002540:Cerebral Cortex / Q000000981:diagnostic imaging; D003545:Cysteine / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D008297:Male; D015609:Organotechnetium Compounds; D010091:Oximes; D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime; D013702:Temporal Lobe / Q000000981:diagnostic imaging*; D013788:Thalamus / Q000000981:diagnostic imaging; D015899:Tomography, Emission-Computed, Single-Photon
D015609:Organotechnetium Compounds; D010091:Oximes; D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime; C059659:technetium Tc 99m bicisate; D003545:Cysteine