Role of Diffusion-Weighted Magnetic Resonance Imaging in the Evaluation of Ovarian Tumours

Abstract

Characterization of adnexal masses calls for multidisciplinary involvement. Though a definitive pathological diagnosis mandates surgical intervention, a pre-interventional near-accurate characterization helps in treatment planning. Imaging is a mainstay in this regard. This study aimed at analysing ADC values of ovarian lesions observed on a DW–MRI, with an intent to arrive at a probable demarcating value differentiating benign and malignant tumours. The significance of contrast enhancement pattern of lesions was also analysed. All patients with histopathologically proven ovarian tumour (benign and malignant) who had pelvic MRI with DW sequence with b value of 0 and 1000 were included. Total patients were 62. Mean age was 44 ± 16.8 years. 33.88% were malignant. DWI and ADC values were plotted in 48 of the 62. Diffusion restriction was seen in 81.25% of malignant and 56.25% of benign lesions. The sensitivity and specificity of DWI in differentiating malignancies were 81.25% and 43.75%, respectively. The probable cut-off value of ADC differentiating a malignant and a benign lesion was found to be ≥ 1.13 × 10−3 mm2/s, statistically, using the receiver operating characteristics. 35.48% had early contrast enhancement, and 64.51% delayed enhancement. DWI has an optimal sensitivity of 81.25% and a low specificity of 43.75% in differentiating malignant from benign lesions. In our study, we found an ADC cut-off of ≥ 1.13 × 10−3 mm2/s, to differentiate between malignant and benign tumours with a sensitivity of 84.4% and specificity of 87.5%. In differentiating between benign and malignant lesions, early enhancement on dynamic contrast study had a good sensitivity.