Comparison of DVRs Measured with Full Kinetic Modeling Against Reference Tissue Model and Simple Ratio Technique
| Parameter | DVR | Reference region | Ratio | ||||||
|---|---|---|---|---|---|---|---|---|---|
| MB | THAL | STR | MB | THAL | STR | MB | THAL | STR | |
| Mean ± SD | 2.16 ± 0.23 | 1.70 ± 0.19 | 1.58 ± 0.15 | 2.01 ± 0.17 | 1.63 ± 0.16 | 1.53 ± 0.12 | 2.23 ± 0.22 | 1.83 ± 0.18 | 1.68 ± 0.19 |
| Test–retest (%) | 7.7 | 3.5 | 6.3 | 5.4 | 2.3 | 4.6 | 7.6 | 3.9 | 8.2 |
| Intersubject (%) | 5.3 | 8.8 | 6.8 | 5.2 | 8.1 | 5.4 | 6.9 | 7.1 | 9.8 |
| ri | 0.32 | 0.46 | 0.22 | 0.03 | 0.64 | 0.15 | 0.09 | 0.40 | 0.48 |
| DVR R2 | 0.94 | 0.97 | 0.95 | 0.89 | 0.98 | 0.93 | |||
| DVR slope | 0.72 ± 0.07 | 0.86 ± 0.06 | 0.79 ± 0.07 | 0.93 ± 0.12 | 0.97 ± 0.05 | 1.23 ± 0.13 | |||
MB = midbrain; THAL = thalamus; STR = striatum; Test–retest = mean absolute difference between each subject’s mean value and each individual value; Intersubject = between-subject variability, calculated same way as Test–retest; ri = intraclass correlation coefficient; R2 = correlation coefficient of simplified methods against full kinetic model; slope = gradient of regression between simplified methods of analysis and full kinetic model.