Fig. 1

Fat-suppressed post contrast T1-weighted image. a A 9-mm oval circumscribed mass (arrow of a) on Case 1. b Segmental clumped non-mass enhancement (circle of b) on Case 2. c A 6-mm round circumscribed mass on the chest wall side (arrow of c) on Case 3. d A 3-mm enhanced nodule (focus) (arrow of d) on Case 4. e Three months later from first screening MRI, no significant change (arrow of e) on Case 4. f Nine months later from first screening MRI, the lesion was increased as a 10-mm not-circumscribed and heterogeneous enhanced mass (arrow of f) on Case 4