Dynamic Contrast Enhancement Magnetic Resonance Imaging Evaluation of Breast Lesions: a Morphological and Quantitative Analysis

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U Sivarajan, KJ Jayapragasam, YF Abdul Aziz, K Rahmat, SI Bux

Hong Kong J Radiol 2009;12:43-52

Objective: To correlate the qualitative and quantitative characteristics of breast lesions on magnetic resonance imaging with histopathology.

Methods: Diagnostic dynamic contrast-enhanced magnetic resonance imaging of the breast was performed with a double breast coil at 1.5 T for 43 lesions. The diagnostic images were evaluated on a workstation. Lesion morphology (size, shape, margin type, enhancement pattern), signal intensity parameters (time to peak enhancement, maximum slope of enhancement curve, washout), and scores analogous to the Breast Imaging Reporting and Data System categories were correlated with the histology.

Results: The sensitivity of breast magnetic resonance imaging for carcinoma was 85.7%. The relatively low specificity of magnetic resonance imaging for benign lesions (82.8%) was due to overlapping features between benign and malignant pathology, including granulomatous mastitis, fibroadenoma with atypical ductal hyperplasia, fibrocystic changes, sclerosing adenosis, and normal breast parenchyma. Irregular margins of a focal mass and rim-like enhancement were morphologic criteria that correlated with malignancy, with positive predictive values of 75.0% and 83.3%, respectively. Malignant and benign lesions did not differ significantly in any of the quantitatively evaluated signal intensity parameters. Carcinomas showed a tendency toward faster and stronger enhancement and stronger washout than the benign lesions. Nevertheless, there was a considerable overlap of both parameters.

Conclusions: Benign breast pathology may mimic malignancy on magnetic resonance imaging. A combination of morphologic and perfusion parameters helps the classification of breast lesions by magnetic resonance imaging. Due to the overlap in enhancement characteristics between benign and malignant lesions, quantitative signal intensity data alone is not sufficient. An awareness of the problematic factors of breast magnetic resonance imaging will improve diagnostic accuracy and enable understanding of the limitations of this modality.