Diffusion-weighted imaging in breast lesion evaluation

Abstract

Purpose: The purpose of this study was to investigate the ability of diffusion-weighted imaging (DWI) and the apparent diffusion coefficient (ADC) in the detection and characterisation of breast lesions.

Materials and methods: From September 2005 to September 2007, 86 patients with breast lesions who underwent magnetic resonance imaging (MRI) in our department were included in our study. MRI was performed with a 1.5-T unit using a standard protocol including DWI sequence. For each breast lesion, the ADC value was calculated and compared with that of normal breast tissue and to the definitive pathological diagnosis. Mann-Whitney U and Kruskal-Wallis tests were used for statistical analysis.

Results: A total of 126 breast lesions were detected. Pathology results revealed 100 malignant and 26 benign lesions. Mean diameter of lesions was 26.02 mm (range 4-90 mm), including 52 lesions <or=15 mm in size. Mean ADC value of normal glandular tissue was 1.55x10(-3) mm(2)/s. Mean ADC value of malignant lesions was 0.97x10(-3) mm(2)/s. Mean ADC value for benign lesions was 1.66x10(-3) mm(2)/s. Benign lesions showed ADC values significantly higher than malignant lesions (p<0.0001).

Conclusions: DWI provides reliable information to support MRI diagnosis of breast masses. ADC value appears a promising adjunctive parameter in distinguishing malignant from benign breast lesions.