Magnetic resonance imaging of the breast as a problem-solving method: to be or not to be?

The use of dynamic magnetic resonance imaging (MRI) of the breast as a complementary problem-solving tool was explored in a heterogeneous population sample. A total of 3,076 patients that underwent breast MRI examination between January 2008 and June 2012 in our center were screened retrospectively. Of these, 868 met the following inclusion criteria and were considered eligible for the study: available data on clinical signs, symptoms and on the results of mammography and ultrasound examinations in medical records; at least 1 year of follow-up; and documented pathology findings. Lesions with a stable course over a follow-up period of at least 12 months were considered benign. MRI was suggestive of a suspicious abnormality (BI-RADS 4) or highly suggestive of malignancy (BI-RADS 5) in 129 (15%) of 868 patients, leading to a biopsy examination in these cases. On the other hand, MRI findings were considered normal in 739 (85%) subjects based on normal (BI-RADS 1), benign (BI-RADS 2) or probably benign (BI-RADS 3) findings. Of the 129 patients undergoing a histopathologic examination based on MRI findings, 63 were diagnosed with cancer, and in 66, the biopsy proved to be benign. Forty of the 63 patients (40/63) with a diagnosis of malignancy and 34 of the 66 patients (34/66) with a benign diagnosis had been categorized as BI-RADS 4 with conventional methods. A total of 23 patients with BI-RADS category of 0 to 3 according to conventional methods were diagnosed as having cancer with MRI. In six of these, the family history was positive. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of MRI for the detection of cancer were 100%, 92%, 52%, and 100%, respectively. In cases with inconclusive findings on conventional imaging studies or in patients with clinical/radiological suspicion of malignancy, MRI should be more effectively used as a problem-solving approach owing to its high sensitivity and NPV in this condition. Use of MRI as a problem-solving method in such cases may decrease rather than increase unnecessary biopsy procedures and patient anxiety.