Retention of Tc-99m ECD in delayed SPECT of the brain.
We determined the effect of retention on the changes in regional biodistribution of Tc-99m ECD in the brain. A total of 14 cases, 7 normal volunteers and 7 patients with various diagnoses but with very minimal radiologic findings or none were included in the study. SPECT images were taken at 30 min, 1, 2, 3, 4 and 6 hrs after an intravenous injection. Retention rates were calculated in various regions and were corrected according to the time decay of technetium. There was a tendency for the retention rate to increase up to three hours of imaging and then a decrease was noted in most regions of the brain. In the thalamus, increasing retention was noted. In conclusion, Tc-99m ECD retention in the different regions of the brain varies with time. These differences should always be considered when planning and interpreting SPECT quantitative studies.
Flores
L G
LG
Department of Radiology, Miyazaki Medical College, Kiyotake, Japan.
Jinnouchi
S
S
Nagamachi
S
S
Ohnishi
T
T
Futami
S
S
Nakahara
H
H
Shimoshinbara
S
S
Ushinbana
K
K
Tamura
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000378:metabolism; D019275:Radiopharmaceuticals / Q000378:metabolism; D015899:Tomography, Emission-Computed, Single-Photon
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C059659:technetium Tc 99m bicisate; D003545:Cysteine