TABLE 1

Baseline scan parameters and plasma analysis (n = 10 subjects)

[11C]Raclopride[11C]NPA
BaselineAfter AmphetamineBaselineAfter Amphetamine
Injected dose (mCi)8.4 ± 0.37.8 ± 0.98.2 ± 0.38.4 ± 0.3
Specific activity (Ci/mmol)1574 ± 4761723 ± 7702270 ± 4912018 ± 520
Injected mass (μg)2.0 ± 0.71.9 ± 1.01.1 ± 0.31.3 ± 0.3
Plasma free fraction (fP, %)11.6 ± 3.211.5 ± 3.19.3 ± 2.09.4 ± 2.2
Nondisplaceable free fraction (fND, %)28.4 ± 5.930.2 ± 5.52.9 ± 0.93.0 ± 0.9
Clearance (l/h)11.7 ± 5.012.4 ± 2.9118.5 ± 17.5129.4 ± 25.1
Cerebellum VT (ml · cm−3)0.41 ± 0.070.38 ± 0.08*3.31 ± 0.773.20 ± 0.86
Plasma amphetamine (0 min, ng · ml−1)65.9 ± 12.773.9 ± 5.4
Plasma amphetamine (30 min, ng · ml−1)61.8 ± 11.269.7 ± 8.2
Plasma amphetamine (60 min, ng · ml−1)61.1 ± 11.567.0 ± 8.2
  • * p < 0.05, paired t test, baseline compared with postamphetamine condition; plasma amphetamine times are relative to the postamphetamine PET scan.