Diffusion-weighted magnetic resonance imaging in the assessment of ovarian masses with suspicious features: Strengths and challenges

ObjectiveTo evaluate diagnostic performance of diffusion weighted imaging (DWI) in evaluating ovarian masses with suspicious features on magnetic resonance imaging (MRI).Patients and methodsPelvic MRI and DWI assessed 235 complex and solid ovarian masses of suspicious MRI features. On DWI, scanning acquired by b values: 0, 500, 1000 and 1500. Analysis considered signal intensity (SI) at b1000 and the mean ADC values for the solid components of the masses.ResultsIncluded masses proved benign in 75(32%), borderline (low potential malignancy) in 55(23.4%) and malignant in 105(44.6%). Restricted diffusion was observed in all of the invasive malignancy (57.1%, n = 105/184). Benign and borderline tumors with high DWI SI presented 15.2% and 27.7% respectively (P < 0.05). The mean ADC value was 1.2 + 0.34 × 10−3 mm2/s, 1.1 + 0.06 × 10−3 mm2/s, and 0.83 + 0.15 × 10−3 mm2/s for benign, borderline and malignant masses respectively. The ADC values of malignant masses and benign masses with fibrous components showed no significant difference (P = 0.333). Significant difference was detected in those with fatty tissue (P = 0.002).ConclusionDWI supported by conventional MRI data can confirm or exclude malignancy in suspicious ovarian masses. The combined analysis of quantitative and qualitative criteria and knowledge of the sequence pitfalls are required.