[Quantification of cerebral blood flow using 123I-IMP SPECT--a new method of estimating the input function from brain dynamic data].
In order to avoid continuous arterial blood sampling, we estimated input function by the method in that the whole brain time activity curves were fitted by two-term exponential function and differentiated analytically after the injection of N-isopropyl-p-[123I]iodoamphetamine (123I-IMP). This method was applied to 4 patients with cerebral infarction and 2 patients with brain tumor. Values of regional cerebral blood flow (rCBF) were calculated from the input function calibrated by one-point arterial sampling at 5 minutes after the injection using microsphere method, and then were compared with those obtained from the table-lookup method. In this study, we used the individual input function for the table-lookup method instead of the standard input function. The overall accuracy errors between two-term exponential functions and the whole brain time-activity curves were about 1%. The values of rCBF calculated by this method were well correlated with those by the table-lookup method (r = 0.901, p < 0.001). Optimal calibration time for this method was between 3-minute and 10-minute after 123I-IMP injection and the deviation of the rCBF values obtained by this method from those obtained by the table-lookup method in which the input function was calibrated at 5 minutes remained within 10%. This method is a less invasive and convenient alternative to the conventional methods which require continuous arterial blood sampling.
Ohnishi
H
H
Department of Radiology, Shiga University of Medical Science.
Tsuji
A
A
Lee
H
H
Takada
M
M
Masuda
K
K
Matsuda
M
M
Yamamoto
I
I
Morita
R
R
D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology; D002138:Calibration; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D003625:Data Collection; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D020367:Iofetamine; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D007457:Iodine Radioisotopes; D020367:Iofetamine