Table 3.

Lifetime attributable risk of thyroid cancer after three- and four-phase parathyroid computed tomography (CT)

Age at exposure (years)	Cases per 1,000,000 people exposed (n)
	Three-phase CT		Four-phase CT
	Male	Female	Male	Female
0–9	246	1255	328	1677
10–19	136	709	182	948
20–29	68	355	91	474
30–39	41	177	55	237
40–49	14	82	18	109
50–59	14	27	18	36
60–69	0	14	0	18
70–79	0	0	0	0