Difference of least square means in perfusion parameters between reference dataset and noise datasets across all ROIs in all participants and across ROIs in participants with perfusion abnormalities (subanalysis)
| Perfusion Parameter | Simulated Exposure (mAs) | All ROIs | Only in ROIs with Perfusion Abnormalities | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Difference from Reference Dataset | Standard Error | P | Adj P | Difference from Reference Dataset | Standard Error | P | Adj P | ||
| CBF (mL/100 g/min) | 188 | −0.12 | 0.68 | .87 | >.99 | −0.35 | 0.86 | .69 | >.99 |
| 177 | −0.20 | 0.68 | .77 | >.99 | −0.22 | 0.86 | .80 | >.99 | |
| 167 | −0.72 | 0.68 | .29 | .73 | −0.67 | 0.86 | .44 | .90 | |
| 127 | −0.60 | 0.68 | .38 | .85 | −0.01 | 0.86 | .99 | >.99 | |
| 44 | −1.81 | 0.68 | .01 | .04 | 0.47 | 0.86 | .58 | .97 | |
| CBV (mL/100 g/min) | 188 | 0.00 | 0.02 | .89 | >.99 | −0.01 | 0.02 | .74 | >.99 |
| 177 | 0.00 | 0.02 | .91 | >.99 | 0.00 | 0.02 | .99 | >.99 | |
| 167 | 0.00 | 0.02 | .92 | >.99 | 0.00 | 0.02 | .93 | >.99 | |
| 127 | 0.02 | 0.02 | .26 | .68 | 0.01 | 0.02 | .62 | .98 | |
| 44 | 0.07 | 0.02 | <.0001 | <.001 | 0.10 | 0.02 | <.0001 | <.0001 | |
| MTT (sec) | 188 | 0.00 | 0.06 | .94 | >.99 | 0.03 | 0.10 | .79 | >.99 |
| 177 | 0.02 | 0.06 | .74 | >.99 | 0.05 | 0.10 | .66 | >.99 | |
| 167 | 0.06 | 0.06 | .32 | .78 | 0.07 | 0.10 | .47 | .92 | |
| 127 | 0.11 | 0.06 | .08 | .28 | 0.07 | 0.10 | .51 | .95 | |
| 44 | 0.46 | 0.06 | <.0001 | <.001 | 0.33 | 0.10 | .00 | .01 | |
Note:—ROIs with perfusion abnormalities were identified by a trained neuroradiologist (P.S.) with 12 years of experience.
Adj P indicates adjusted P value.