Spontaneous T1-hyperintensity within an ovarian lesion: spectrum of diagnoses

Whenever elevated signal intensity is displayed at magnetic resonance imaging (MRI) within an ovarian lesion on unenhanced T1-weighted sequences, some specific diagnoses should be considered because only 3 main components may be responsible for this T1-hyperintensity at MRI: fat, blood products, and proteinaceous or mucinous material. The associated clinical data and concomitant use of T2-weighted sequences and fat-saturation techniques is mandatory to make this tissue characterization possible. The goal of this pictorial review is to provide a simple radiologic reasoning and the differential diagnoses to consider in the presence of spontaneous elevated signal intensity on T1-weighted sequences within a cystic or solid ovarian tumour. (author)