Quantitative measurement of regional cerebral blood flow using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography.
We have developed a quantitative method of measuring regional cerebral blood flow (rCBF) by using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography (SPECT). Twenty-five dynamic SPECT images (24 sec/scan) were collected immediately after tracer injection using a ring-type SPECT system and the accumulation curve (C(t)) was obtained. The time-activity curve corresponding to the arterial blood activity curve was used as B(t). The latter curve was calculated from the lung time-activity curve monitored during scanning and corrected by the actual activity obtained by one-point blood sampling 5 min after tracer injection. The octanol extraction ratio during scanning was considered to be constant and taken as the value measured 5 min after tracer injection (E). The uptake constant (K) per pixel was calculated by the least squares fitting method as the slope of the linear relationship in which C(t)/E x B(t) was plotted against E x integral of t(o)B(tau)d tau/E x B(t). Functional maps of rCBF values were obtained on a 64 x 64 matrix by calculating the uptake constant per pixel and the cross calibration factor (CF) between the SPECT system and a well counter (rCBF = K.CF x 100).
Takeshita
G
G
Department of Radiology, Fujita Health University School of Medicine, Aichi, Japan.
Maeda
H
H
Nakane
K
K
Toyama
H
H
Sakakibara
E
E
Komai
S
S
Takeuchi
A
A
Koga
S
S
Ono
M
M
Nakagawa
T
T
D000328:Adult; D000368:Aged; D000662:Amphetamines; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D020367:Iofetamine; D008297:Male; D008875:Middle Aged; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D000662:Amphetamines; D007457:Iodine Radioisotopes; D020367:Iofetamine