Effect of selecting a fixed dephosphorylation rate on the estimation of rate constants and rCMRGlu from dynamic (18F) fluorodeoxyglucose/PET data

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Journal of Nuclear Medicine; (USA)

OSTI ID:5362200

Dhawan, V; Moeller, J R; Strother, S C; Evans, A C; Rottenberg, D A ^[1]

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1. Memorial Sloan-Kettering Cancer Center, New York, NY (USA)

Several publications have discussed the estimation and physiologic significance of regional ({sup 18}F)fluorodeoxyglucose (FDG) rate constants and metabolic rates. Most of these studies analyzed dynamic data collected over 45-60 min; three rate constants (k1-k3) and blood volume (Vb) were estimated and the regional cerebral metabolic rate for glucose (rCMRGlu) was subsequently derived using the measured blood glucose value and a regionally invariant value of the lumped constant (LC). The dephosphorylation rate constant (k4) was either neglected, or a fixed value was used in the estimation procedure to obtain the remaining parameters. To compare the rate constants obtained by different authors using different values of k4 is impossible without knowledge of the effect of selecting different fixed values of k4 (including zero) on the estimated rate constants and rCMRGlu. Based on our analysis of FDG/PET data from nine normal volunteer subjects, we conclude that inclusion of a fixed value for k4, in spite of a scaling effect on the absolute values of model parameters, has no effect on the coefficient of variation (CV) of within- and between-subject parameter estimates and glucose metabolic rates.

• OSTI ID: 5362200
• Journal Information: Journal of Nuclear Medicine; (USA), Journal Name: Journal of Nuclear Medicine; (USA) Vol. 30:9; ISSN 0161-5505; ISSN JNMEA
• Country of Publication: United States
• Language: English

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550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ALDEHYDES
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