Table 3 Association between type of radiation protection device (apron versus shield) and most inferior vertebra visible.
From: Thyroid shields and neck exposures in cephalometric radiography
Thyroid Shield | Apron | No lead shield | |
|---|---|---|---|
N = 231 (19.2%) | N = 197 (16.6%) | N = 763 (64.1%) | |
C1 | 3 (1.3%) | - | 1 (0.1%) |
C2 | 31 (13.5%) | 3 (1.5%) | 4 (0.5%) |
C3 | 163 (71.2%) | 45 (22.7%) | 27 (3.5%) |
C4 | 30 (13.1%) | 94 (44.8%) | 112 (14.7%) |
C5 | 2 (0.9%) | 49 (24.8%) | 306 (40.1%) |
C6 | - | 5 (2.5%) | 234 (30.7%) |
C7 | - | 1 (0.5%) | 57 (7.5%) |
T1 | - | 1 (0.5%) | 13 (1.1%) |
T2 | - | - | 9 (0.8%) |