Time-resolved gadolinium-enhanced MR imaging of the breast: Impact on accuracy of diagnosis of breast carcinoma.

Abstract

33 Background: The purpose of the study is to differentiate benign and malignant breast lesions based on very early enhancement of the lesion on time-resolved gadolinium-enhanced MR imaging. Methods: 100 women with breast lesions were examined at 1.5 T (Siemens, Erlangen, Germany), by fast T1-weighted GRE images every 5 s for 1 min after injection of Gd-DOTA (Dotarem, Guerbet, France), followed by 5 spacially-resolved MR image series every 30 s. Images were subtracted; maximum-intensity-projection images were obtained; and images were randomized and reviewed by two blinded readers, who reviewed only the spacially-resolved MR images and gave BIRADS diagnosis. After one month, they evaluated only the time-resolved MR images and noted the time of first appearance of enhancement. Results: The patients had 249 enhancing lesions: 66 malignant on histopathology and 183 benign on basis of histopathology or 1-year imaging follow-up. On time-resolved MR imaging, 15 lesions enhanced at 0-5 s (all malignant), 23 at 5-10 s (21 malignant, 2 benign), 34 at 10-15 s (28 malignant, 6 benign), and 117 at 15-20 s (2 malignant, 115 benign). All malignant lesions enhanced before 20 s. Taking 15s as the cut-off point, early enhancement had sensitivity of 96.9%, specificity of 95.6%, positive predictive value of 88.8%, negative predictive value of 98.8%, and accuracy of 95.9% for diagnosis of carcinoma. Enhancement before 15 s corrected BIRADS diagnosis of the spacially-resolved MR imaging in 14 lesions (5.6%). Conclusions: Lesion enhancement in the first 15s on time-resolved MR imaging is a useful sign for the diagnosis of breast carcinoma.