Visibility of mammographically occult breast cancer on diffusion-weighted MRI versus ultrasound

To investigate the visibility of mammographically occult breast cancers on diffusion-weighted MRI (DWI) versus ultrasound. 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. 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). DWI may detect more mammographically occult cancers than ultrasound, warranting further investigation as an alternative supplemental screening technique. •Many mammographically occult breast cancers are visible on non-contrast DWI.•As a supplemental screening technique to mammography, DWI may detect more additional breast cancers than ultrasound.•DWI may better detect larger cancers and those in younger women versus ultrasound.•DWI continues to show promise as an effective supplemental breast screening tool.