Table 2.
Statistical results of quantitative DSC and iVASO measures from all 12 patients.
| DSC MRI | iVASO MRI | ||||
|---|---|---|---|---|---|
| CBV (ml/100 ml) | MTT (s) | CBVa (ml/100 ml) | ATT (ms) | ||
| WHO grade II (n=6) | |||||
| Tumoral region | 3.28±0.96 f | 5.08±0.70 | 0.25±0.31 | 103.66±93.73 | |
| Contralateral region | 2.62±0.77 | 4.92±0.48 | 0.97±0.51 | 417.28±106.56 | |
| Tumor/contralateral a | 1.30±0.40 | 1.03±0.14 | 0.25±0.30 | 0.32±0.36 | |
| Relative change (%) b | 25.27 | 3.05 | −74.70 | −75.20 | |
| Effect size c | 0.76 | 0.25 | −1.71 | −3.13 | |
| Adjusted P d | 0.15 | 0.60 | 0.03 | 0.01 | |
| SNR e | tumor | 10.99±4.74 | 11.42±5.29 | ||
| contralateral | 11.29±2.74 | 11.17±6.61 | |||
| CNR e | 2.82±0.91 | 0.34±0.12 | −8.44±4.32 | −8.49±4.37 | |
| WHO grade III (n=3) | |||||
| Tumoral region | 4.37±1.82 | 5.54±1.01 | 0.72±0.91 | 327.59±392.57 | |
| Contralateral region | 5.01±1.85 | 5.67±1.00 | 1.30±0.05 | 340.56±105.83 | |
| Tumor/contralateral | 0.86±0.08 | 0.98±0.01 | 0.55±0.67 | 1.17±1.61 | |
| Relative change (%) | −12.80* | −2.28 | −44.62* | −3.81 | |
| Effect size | −0.35 | −0.13 | −0.9 | −0.05 | |
| Adjusted P | 0.12 | 0.05 | 0.37 | 0.97 | |
| SNR | tumor | 12.86±5.82 | 14.95±2.72 | ||
| contralateral | 11.19±5.68 | 10.31±3.88 | |||
| CNR e | −1.54±0.81 | −0.27±0.13 | −5.63±1.41 | −0.48±0.15 | |
| WHO grade IV (n=3) | |||||
| Tumoral region | 4.82±1.29 | 4.55±0.75 | 1.03±0.31 | 173.34±71.28 | |
| Contralateral region | 2.49±1.39 | 4.86±0.32 | 0.59±0.29 | 550.58±218.98 | |
| Tumor/contralateral | 2.36±1.27 | 0.93±0.11 | 1.88±0.42 | 0.36±0.18 | |
| Relative change (%) | 93.73 | −6.42 | 75.10 | −68.50 | |
| Effect size | 1.74 | −0.54 | 1.49 | −2.32 | |
| Adjusted P | 0.21 | 0.41 | 0.001 | 0.12 | |
| SNR | tumor | 10.58±4.99 | 10.31±2.84 | ||
| contralateral | 10.21±4.09 | 14.19±5.86 | |||
| CNR e | 9.74±4.16 | −0.67±0.31 | 9.20±3.21 | −8.39±2.81 | |
The ratio was defined as (mean value in tumoral region / mean value in similar-sized contralateral region).
Relative change was defined as 100 * (mean value in tumoral region – mean value in contralateral region) / (mean value in contralateral region) %.
Effect size was estimated with Cohen's d = (mean value in tumoral region – mean value in contralateral region) / s, where s is the pooled standard deviation of the two groups.
P-values from the paired two-sided t-Test between tumoral and contralateral regions. Adjusted for multiple comparisons with the Benjamini-Hochberg false discovery rate (FDR) procedure.
Signal-to-noise ratio (SNR) was calculated on the original DSC images and iVASO difference images in each ROI (not on the CBV/MTT/CBVa/ATT maps). Contrast-to-noise ratio (CNR) was defined as SNR * relative change.
mean±standard deviation
Note that the negative average values of these parameters in the WHO grade III group were caused by the mix of oligodendroglioma (one patient) and anaplastic astrocytoma (two patients) cases. Please see Table 1 and text in Results and Discussion for more information.