Table 2.
Patient demographics data and breast lesion characteristics.
| Characteristic | Retrospective Training and Validation sets |
Prospective test sets | |
|---|---|---|---|
| Hospital 1 Set | Hospital 2 Set | ||
| Number of patients | 420 | 214 | 64 |
| Age (years) (mean) | 45 ± 12 | 45 ± 12 | 50 ± 11 |
| Number of lesions | 480 | 228 | 64 |
| Lesion maximum diameter(mm) | |||
| 2-10 | 167(35%) | 89(39%) | 13(20%) |
| 10-20 | 185(38%) | 90(40%) | 34(53%) |
| 20-30 | 128(27%) | 49(21%) | 17(27%) |
| BI-RADS category a | |||
| 2 | 34(7%) | 18(8%) | 0(0%) |
| 3 | 110(23%) | 30(13%) | 10(16%) |
| 4a | 106(23%) | 70(31%) | 8(13%) |
| 4b | 80(17%) | 41(18%) | 14(22%) |
| 4c | 74(15%) | 35(15%) | 22(34%) |
| 5 | 76(16%) | 34(15%) | 10(15%) |
| Lesion type | |||
| Invasive ductal carcinoma | 82(17%) | 26(11%) | 14(22%) |
| Invasive lobular carcinoma | 73(15%) | 43(19%) | 16(25%) |
| Ductal carcinoma in situ | 21(4%) | 10(4%) | 6(9%) |
| Other malignant b | 20(4%) | 4(2%) | 5(8%) |
| Fibroadenoma | 141(30%) | 64(28%) | 13(20%) |
| Other benign c | 143(30%) | 81(36%) | 10(16%) |
The BI-RADS category a is based on the interpretation of the radiologist who originally performed the US examinations before the biopsy test, not the radiologists involved in the reader study. It should be noted that all BI-RADS categories involved in this study were determined on breast-US video images only. b Includes non-specific malignant results. c Includes adenosis, hyperplasia, benign phyllodes tumors, and papillomata.