Fig. 4

Female patient, 40 years old, with history of right ovarian cystectomy, accidentally discovered right ovarian cystic mass by US. a–c Conventional MRI images shows bulky right ovary measuring 3 × 4 × 5 cm AP, C.C, and TS respectively. It shows multiple cysts with thickened wall as well as thickened septations. The cysts elicit hypo-intense TI signal and hyper-intense T2 signal, while the ovarian stroma shows intermediate to hypo-intense signal in T1WI and intermediate signal in T2WI with heterogeneous contrast enhancement of the thick wall and septations in post-contrast image. d Proton MRS (TE = 288 m sec) observed a sharp lipid peak around 1.3 ppm and another small lipid peak is noticed around 0.9 ppm. A sharp NAA peak can also be observed around 2 ppm, Conventional MRI-based diagnosis: right-sided borderline ovarian tumor is highly considered; MRS diagnosis: confirmed the benign nature of the lesion with Cho/Cr ratio 0.67; Pathological diagnosis: granulosa cell tumor