Table 2.
Kinetic parameters obtained with the 2T-CM4k
| Region | K 1 | k 2 | k 3 | k 4 | VT | K1/k2 | k3/k4 | AIC | R 2 |
|---|---|---|---|---|---|---|---|---|---|
| Asymptomatic individuals | |||||||||
| Cer GM | 0.327 (0.08) | 0.235 (0.00) | 0.025 (0.03) | 0.046 (0.04) | 2 (0.1) | 1.39 (0.36) | 0.41 (0.3) | – 11 (2.8) | 0.99 (0.00) |
| PCC | 0.343 (0.03) | 0.237 (0.04) | 0.021 (0.01) | 0.044 (0.01) | 2.2 (0.1) | 1.48 (0.42) | 0.56 (0.52) | – 33.7 (4.3) | 0.99 (0.00) |
| Symptomatic individuals | |||||||||
| Cer GM | 0.230 (0.02) | 0.125 (0.02) | 0.009 (0.01) | 0.01 (0.00) | 3.4 (0.8) | 1.88 (0.37) | 0.86 (0.5) | – 2.0 (55) | 0.99 (0.00) |
| PCC | 0.246 (0.08) | 0.099 (0.01) | 0.052 (0.03) | 0.01 (0.00) | 14.2 (5.6) | 2.45 (0.56) | 5.11 (2.6) | – 3.7 (17) | 0.99 (0.00) |
Mean (standard deviation) of kinetic parameters obtained with the reversible two-tissue compartment model with four parameters (2T-CM4k) in the cerebellar gray matter (Cer GM) and posterior cingulate cortex (PCC) of asymptomatic (young and elderly cognitively healthy) and symptomatic (mild cognitive impairment and Alzheimer’s disease) individuals who underwent arterial sampling
AIC Akaike information criterion, K1 (ml/cm3/min) transport rate for influx of tracer across blood–brain barrier, k2 (1/min) transport rate for efflux of tracer across blood–brain barrier, k3 (1/min) rate constant for exchange from nondisplaceable (free and nonspecific tracer) to specific binding compartment, k4 (1/min) rate constant for exchange from specific binding compartment to nondisplaceable