Table 1.
Performance measures for screening and diagnostic breast MRI
| Screening | Diagnostic | Overall | |
|---|---|---|---|
| Patient Age Mean (standard deviation) | 51.1 yrs (10.3) | 50.6 yrs (10.6) | 50.9 yrs (10.5) |
| Total # of MRIs performed | 1,313 | 1,131 | 2,444 |
| # Positive MRIs (BI-RADS 0,4,5) | 152 | 194 | 346 |
| Final BI-RADS 4 or 5 | 75 | 149 | 224 |
| Biopsies (lesion level) | 77 | 172 | 249 |
| Biopsies (exam level) | 67 | 139 | 206 |
| Cancer diagnoses (lesion) | 18 | 61 | 79 |
| Cancer diagnoses (exam) | 18 | 54 | 72 |
| Cancer detection rate (per 1000 exams) | 14 | 47* | 29* |
| Abnormal interpretation rate | 152/1313 (12%) | 194/1131 (17%) | 346/2444 (14%) |
| PPV1 | 18/152 (12%) | 54/194 (28%) | 72/346 (21%) |
| PPV2 | 18/75 (24%) | 53/149 (36%)* | 71/224 (32%)* |
| PPV3 (exam level) | 18/67 (27%) | 53/138 (38%)* | 71/205 (35%)* |
*
One patient underwent a diagnostic breast MRI due to her current history of breast cancer. Her study demonstrated non mass-like enhancement in the contralateral breast, for which correlative mammography was recommended. Inter-modality correlation was negative, so her final BI-RADS category was probably benign (BI-RADS 3). The patient elected to undergo a prophylactic contralateral mastectomy, with pathology demonstrating an invasive carcinoma in the same quadrant as the non mass-like enhancement. Therefore, this patient is excluded from the cancer detection rate, PPV2, and PPV3 calculations.