Abstract
To improve the measurements of glucose metabolism in the human brain, we imposed biologic constraints on the deoxy-glucose model with and without dephosphorylation of FDG-6-phosphate (the k*/4- and k*/3-models). The constraints included constant transport and phosphorylation ratios (τ and φ) and a common partition volume (K1/k2) for tracer [18F]FDG and glucose. In the presence of significant dephosphorylation, the k*/3-model yielded time-dependent estimates of the phosphorylation coefficient (k*/3), while the k*/4-model yielded time-independent estimates. However, the two models yielded practically identical measurements of regional cerebral glucose metabolism in PET studies of six normal volunteers when the phosphorylation affinity ratio (the k*/3/k3 ratio of FDG and glucose) and tracer circulation time were 0.30 and 20 min for the k*/3-model and 0.33 and 45 min for the k*/4-model.
Original language | English (US) |
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Pages (from-to) | 692-698 |
Number of pages | 7 |
Journal | Journal of Nuclear Medicine |
Volume | 32 |
Issue number | 4 |
State | Published - Jan 1 1991 |
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging