Ultrafast dynamic contrast enhanced (UF-DCE) MRI using compressed sensing enabled very fast scanning of the breast (every 3.7 sec/frame), and separately visualized breast arteries and veins. Breasts with cancers showed significantly shorter time intervals between arterial and venous visualization than the contralateral breasts without cancers. The time intervals in the breast with cancers tended to be shorter than those in the breasts with benign lesions. Shorter time intervals in breasts with cancers may reflect higher vascularity in malignancy. UF-DCE MRI has a potential to enable the differentiation of breast cancers in very early phase (0-60sec after contrast injection).