[A new graphic method for evaluation of distribution volume on N-isopropyl-p-[123I]iodoamphetamine (IMP) SPECT].
We developed a new graphic method using N-isopropyl-p-[123I]iodoamphetamine (IMP) and SPECT of the brain, the graph on which all three parameters, cerebral blood flow, distribution volume (Vd) and delayed count to early count ratio (Delayed/Early ratio), were able to be evaluated simultaneously. The kinetics of 123I-IMP in the brain was analyzed by a 2-compartment model, and a standard input function was prepared by averaging the time activity curves of 123I-IMP in arterial blood on 6 patients with small cerebral infarction etc. including 2 normal controls. Being applied this method to the differential diagnosis between Parkinson's disease and progressive supranuclear palsy, we were able to differentiate both with a glance, because the distribution volume of the frontal lobe significantly decreased in Parkinson's disease (Mean +/- SD; 26 +/- 6 ml/g). This method was clinically useful. We think that the distribution volume of 123I-IMP may reflect its retention mechanism in the brain, and the values are related to amine, especially to dopamine receptors and its metabolism.
Odano
I
I
Department of Radiology, Niigata University School of Medicine.
Ohkubo
M
M
Takahashi
N
N
Ohtaki
H
H
Noguchi
E
E
Hatano
M
M
Yamasaki
Y
Y
Yokoi
T
T
Nishihara
M
M
D000368:Aged; D000662:Amphetamines / Q000493:pharmacokinetics; D001921:Brain / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D020367:Iofetamine; D008297:Male; D008954:Models, Biological; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D013494:Supranuclear Palsy, Progressive / Q000000981:diagnostic imaging / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D000662:Amphetamines; D007457:Iodine Radioisotopes; D020367:Iofetamine