Average eye lens dose for each imaging protocol with CTDIvol and DLP measurements*
| CT Protocol | MDCT | CARE Dose | CTDIvol (mGy) (mean ± SD) | DLP (mGy.cm) (mean ± SD) | Eye Lens Dose (mGy) (mean ± SD) | PValue | No. |
|---|---|---|---|---|---|---|---|
| Brain (tilted axial mode) | 16 | + | 63.36 ± 2.18 (60.48, 65.86) | 930.50 ± 61.08 (847.00, 988.00) | 15.56 ± 4.18 (10.20, 22.50) | NS (.183) | 1 |
| – | 67.20 ± 0 (67.20, 67.20) | 985.67 ± 32.26 (941.00, 1008.00) | 18.14 ± 7.59 (10.60, 36.00) | 2 | |||
| Brain (helical mode) | 16 | + | 83.44 ± 0.42 (83.15, 84.02) | 1421.33 ± 94.54 (1301.00, 1512.00) | 82.16 ± 13.43 (56.50, 97.90) | NS (.096) | 3 |
| – | 84.30 ± 0 (84.30, 84.30) | 1449.67 ± 94.43 (1319, 1517) | 88.83 ± 13.47 (65.30, 102.60) | 4 | |||
| 64 | + | 36.77 ± 1.76 (35.31, 39.34) | 601.33 ± 47.48 (559, 669) | 47.18 ± 5.99 (36.2, 60.0) | <.000 | 5 | |
| – | 53.33 ± 0.06 (53.30, 53.46) | 870.83 ± 32.00 (831, 909) | 63.90 ± 7.74 (49.10, 75.90) | 6 | |||
| Paranasal sinus navigation | 16 | + | 40.57 ± 0.66 (39.42, 41.14) | 563.67 ± 28.24 (524, 595) | 45.90 ± 2.65 (40.3, 50.00) | <.000 | 7 |
| 64 | + | 20.69 ± 0.77 (19.96, 21.82) | 301.83 ± 7.11 (289, 310) | 28.96 ± 3.35 (22.80, 35.30) | 8 | ||
| Temporal bone/orbits | 16 | + | 102.86 ± 7.08 (92.71, 109.31) | 483.33 ± 48.84 (424, 541) | 98.58 ± 9.03 (83.00, 111.7) | <.000 | 9 |
| 64 | + | 46.71 ± 2.07 (43.88, 48.59) | 298.50 ± 20.97 (270, 318) | 53.57 ± 10.07 (39.10, 70.50) | 10 |
Note:—NS indicates not significant; CTDIvol, volume CT dose index; DLP, dose-length product.
* The CTDIvol, DLP, and eye lens doses are tabulated as mean ± SD with the minimum and maximum values in parentheses. Comparison was made between protocols using the paired Student t test, and statistical significance was defined at P < .05.