[Compartment analysis of 123I-IMP brain SPECT].
To clarify the kinetics of N-isopropyl [123I]p-iodoamphetamine (IMP) in the brain, 2-compartment analysis was applied for brain SPECT with 57-minute dynamic scan in 9 subjects. The model consisted of blood component and brain tissue component. Two transfer rate constants were defined; k1 showed the rate from the blood to the brain tissue, and k2 was that of back diffusion. The late scan was performed 210 minutes after the tracer injection. Suitable k values best fitting to the dynamic data were determined for all regions of interest. Predicted regional cerebral activity at 210 minutes using 57-minute dynamic data was well agreed with measured activity. These showed the kinetics of IMP in the brain was well described by the 2-compartment model. The partition coefficient (k1/k2 ratio) was as large as about 35, and almost constant in the various brain structures including hypoperfused areas. These findings indicated that the initial IMP images reflected the reasonable CBF distribution, which gave relatively reliable CBF values even if using microsphere model.
Higano
S
S
Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels, Akita.
Shishido
F
F
Aizawa
Y
Y
Miura
S
S
Murakami
M
M
Inugami
A
A
Kanno
I
I
Fujita
H
H
Uemura
K
K
D000662:Amphetamines; D001921:Brain / Q000000981:diagnostic imaging*; D002544:Cerebral Infarction / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation; D006801:Humans; D007457:Iodine Radioisotopes; D020367:Iofetamine; D008955:Models, Cardiovascular; D015899:Tomography, Emission-Computed, Single-Photon
D000662:Amphetamines; D007457:Iodine Radioisotopes; D020367:Iofetamine