Table 1.

Relative radiation level designations

Relative Radiation Level	Adult Effective Dose Estimate Range (mSv)	Pediatric Effective Dose Estimate Range (mSv)
○	0	0
☢	<0.1	<0.03
☢ ☢	0.1–1	0.03–0.3
☢ ☢ ☢	1–10	0.3–3
☢ ☢ ☢ ☢	10–30	3–10
☢ ☢ ☢ ☢ ☢	30–100	10–30

Note: Relative radiation level assignments for some of the examinations cannot be made, because the actual patient doses in these procedures vary as a function of a number of factors (eg, region of the body exposed to ionizing radiation, the imaging guidance that is used). The relative radiation levels for these examinations are designated as “Varies.”