Characterization of ductal carcinoma in situ on diffusion weighted breast MRI

Objectives To characterize ductal carcinoma in situ (DCIS) and its subtypes on diffusion-weighted imaging (DWI). Methods We retrospectively reviewed 74 pure DCIS lesions in 69 women who underwent DWI at 1.5 T (b = 0 and 600 s/mm 2 ). Each lesion was characterized by qualitative DWI intensity, quantitative DWI lesion-to-normal contrast-to-noise ratio (CNR), and quantitative apparent diffusion coefficient (ADC). The detection rate was calculated with predetermined thresholds for each parameter. The effects of lesion size, grade, morphology, and necrosis were assessed. Results Ninety-six percent (71/74) of DCIS lesions demonstrated greater qualitative DWI intensity than normal breast tissue. Quantitatively, DCIS lesions demonstrated on average 56% greater signal than normal tissue (mean CNR = 1.83 ± 2.7) and lower ADC values (1.50 ± 0.28 × 10 −3 mm 2 /s) than normal tissue (2.01 ± 0.37 × 10 −3 mm 2 /s, p