Diffusion-weighted MRI of the breast:lesion characterization and parameter selection / 中华放射学杂志

ABSTRACT

Objective To evaluate the b value of diffusion-weighted(DW)MRI in distinguishing between benign and malignant breast lesions.Methods Three diffusion-weighted sequences were implemented with 500,1000 and 2000 s/mm~2 b values respectively on 95 breast lesions in 83 patients.All lesions were confirmed by pathology.The apparent diffusion coefficient(ADC)values and signal intensity (SI)were recorded and compared in different lesions(breast cancer,benign lesion,cyst and normal beast tissue)with the same b value and the same lesions with the different b values.Results(1)The mean ADC value and SI of breast cancer were 1.375?0.378 and 839.713?360.493 respectively with b= 500 s/mm~2,1.176?0.311 and 459.314?229.609 with b=1000 s/mm~2,0.824?0.198 and 243.825? 110.616 with b=2000 s/mm~2.The differences in the mean ADC value were significant between two type lesions(cancer and benign lesion,cancer and cyst,cancer and normal breast tissue)with b values of 500 s/mm~2 and 1000 s/mm~2.But the significant differenee was only seen between cancer and benign lesions when b value was 2000 s/mm~2.(2)The one-side upper limits of 95% confidence interval of mean ADCs were adopted as the point to separate the malignant from the benign lesions,the sensitivity was 70.92%, 70.73% and 69.77%,the specificity was 77.19%,75.70% and 54.76%,the accuracy was 77.12%, 74.32% and 62.35% respectively with b values of 500 s/mm~2,1000 s/mm~2 and 2000 s/mm~2.The areas under ROC eurves were Az_(500)=0.775?0.046(P0.05).Conclusion DWI MRI is useful for the differential diagnosis of breast lesions with b values of 500 s/mm~2 and 1000 s/mm~2.