Mean (SD) dose estimates and objective image-quality measures by age group and scanner
| Younger Than 1.5 yr | 1.5–6 yr | 7–12 yr | Older Than 13 yr | |||||
|---|---|---|---|---|---|---|---|---|
| FBP | IMR | FBP | IMR | FBP | IMR | FBP | IMR | |
| CTDIvol | 29.9 (5.5) | 21.8 (0.1) | 30.6 (5.5) | 22.8 (0.0) | 31.5 (6.2) | 27.5 (0.0)a | 33.3 (6.9) | 29.2 (0.6)a |
| SNRTHAL | 9.3 (2.3) | 22.0 (5.3) | 8.6 (1.8) | 20.2 (3.9) | 8.8 (2.3) | 18.7 (3.2) | 8.6 (2.2) | 17.9 (3.5) |
| SNRWM | 8.3 (2.3) | 16.5 (3.8) | 8.2 (2.3) | 15.8 (3.3) | 7.8 (1.3) | 16.9 (4.3) | 7.9 (2.4) | 14.9 (2.9) |
| CNR | 2.1 (0.9) | 4.9 (1.3) | 2.1 (1.1) | 4.4 (0.9) | 2.0 (1.0) | 3.7 (0.9) | 1.8 (0.6) | 3.6 (1.0) |
Note:—THAL indicates thalamus; WM, white matter; vol, volume.
↵a P value < .003. For all other results, P value < .001, equal variances t test.