ABSTRACT
Purpose:
The purpose of this study is to investigate the role of diffusionweighted magnetic resonance imaging (MRI) in differentiation of benign and malignant breast lesions.
Materials and Methods:
A total of 40 breast lesions (28 benign, 12 malignant) were scanned by routine dynamic contrast-enhanced MRI and diffusion weighted imaging (DWI). The apparent diffusion coefficient (ADC) values of the lesions and normal breast tissue were measured and compared between benign and malignant groups. Also, lesions in benign and malignant groups were seperated according to dynamic contrast enhancement patterns and ADC values were compared. The results were evaluated at different cut-off values by receiver operating characteristic (ROC) curve analysis.
Results:
The mean ADC values were calculated as 0.83 ± 0.3x10-3 mm2/s in malignant lesions, and 1.35 ± 0.2 x10-3 mm2/s in benign lesions. The mean ADC value of the malignant lesions was statistically significantly lower than that of the benign lesions (p<0.001). The mean ADC value of normal fibroglandular tissue was significantly lower in malignant group than that of benign group (p<0.001). When the lesions were seperated according to contrast enhancement – time curves, there were type 1 (n=19), type 2 (n=7) and type 3 (n=1) lesions in benign group and type 2 (n=5) and type 3 (n=7) lesions in malignant group. There was no contrast enhancement in one lesion in the benign group. No significant difference was found between the ADC values of type 1 and type 2 lesions in benign group and type 2 and type 3 lesions in malignant group (p>0.05). In ROC curve analysis, when the cut-off value was taken as 1.01 ± 0.25x10-3 mm2/s (b=1000), the sensitivity was 92.3%, the specificity was 92.5%, and the positive predictive value (PPV) was 85.7%.
Conclusions:
In differentiation of benign and malignant breast lesions, ADC value is a helpful parameter, that could be used together with the morphological criteria and the dynamic contrast enhancement pattern of the lesions. We suggest the routine use of DWI in breast MRI.
