Table 2 Prospective characterization of 1211 solid nodules into BIRADS categories (all 1211 nodules have undergone biopsy)
BIRADS category | Number of nodules biopsied | Number of malignant nodules | Expected risk of cancer (%) | Actual risk of cancer (%) |
|---|---|---|---|---|
2 | 15 | 0 | 0 | 0 |
3 | 231 | 1 | ≤2 | 0.4 |
4a | 515 | 52 | 3–49 | 10 |
4b | 191 | 118 | 50–89 | 62 |
5 | 259 | 236 | ≥90 | 91 |
Total | 1211 | 407 | Â | 34 |