Table 3.
Phantom ADC bias, repeatability metrics, and SNR for each DWI sequence. ADC bias was calculated using the central phantom vial. The ADC bias and within-ROI %CV are expressed as the mean ± standard deviation of the values measured in each of the four replicate images. Tolerance values from the QIBA Profile are included in the last column for comparison.
| EPI (MR-linac) | SPLICE (MR-linac) | TSE (MR-linac) | EPI (MR sim) | BLADE (MR sim) | RESOLVE (MR sim) | QIBA tolerance values | |
|---|---|---|---|---|---|---|---|
| ADC bias (10−3 mm2/s) | 0.026 ± 0.004 | −0.057 ± 0.003 | −0.123 ± 0.002 | −0.015 ± 0.002 | −0.001 ± 0.010 | −0.024 ± 0.010 | ≤ ±0.040 |
| %CV (within-ROI) | 2.55 ± 0.71 | 3.14 ± 0.11 | 3.62 ± 0.30 | 1.76 ± 0.12 | 1.85 ± 0.12 | 8.30 ± 3.04 | ≤ 2 |
| RC (×10−3 mm2/s) | 0.0107 | 0.0082 | 0.0041 | 0.0067 | 0.0269 | 0.0279 | ≤ 0.0150 |
| Repeatability wCV (%) | 0.33 | 0.28 | 0.15 | 0.22 | 0.86 | 0.91 | N/A |
| RDC (×10−3 mm2/s) | 0.0305 | 0.0254 | 0.0027 | 0.0055 | 0.0416 | 0.0049 | ≤ 0.0650 |
| Reproducibility wCV (%) | 0.96 | 0.85 | 0.10 | 0.18 | 1.36 | 0.16 | N/A |
| SNR b = 0 s/mm2 | 87.3 (78.6 – 96.1) |
180.5 (168.0 – 193.0) |
161.3 (146.7 – 175.9) |
171.0 (160.8 – 181.2) |
171.9 (147.5 – 196.3) |
130.2 (112.3 – 148.0) |
≥ 50 ± 5 |
| SNR b = 150 s/mm2 | 118.9 (102.8 – 135.0) |
193.1 (183.6 – 202.6) |
266.2 (242.2 – 290.1) |
N/A | N/A | N/A | N/A |
| SNR b = 500 s/mm2 or b = 800 s/mm2 | 106.7 (94.6 – 118.8) (b = 500) |
184.0 (174.8 – 193.3) (b = 500) |
261.6 (241.6 – 281.7) (b = 500) |
232.2 (222.8 – 241.7) (b = 500) |
104.1 (89.4 – 118.7) (b = 800) |
97.3 (83.5 – 111.1) (b = 800) |
N/A |