Abstract
PURPOSE: To investigate the visibility of mammographically occult breast cancers on diffusion-weighted MRI (DWI) versus ultrasound. MATERIALS AND METHODS: Mammographically occult breast cancers (n=60) initially detected on contrast-enhanced MRI that underwent pre-biopsy targeted ultrasound were retrospectively evaluated for visibility on DWI and ultrasound. RESULTS: More cancers were visible on DWI than ultrasound (78% vs. 63%; p=0.049), with 32 (53%) visible on both and 7 (12%) not visible on either. Visibility differences were more significant in larger lesions (92% vs. 68%, p=0.006). CONCLUSION: DWI may detect more mammographically occult cancers than ultrasound, warranting further investigation as an alternative supplemental screening technique.