Whole-body MRI with diffusion-weighted sequence for staging of patients with suspected ovarian cancer: a clinical feasibility study in comparison to CT and FDG-PET/CT

Objectives To evaluate whole-body MRI with diffusion-weighted sequence (WB-DWI/MRI) for staging and assessing operability compared with CT and FDG-PET/CT in patients with suspected ovarian cancer. Methods Thirty-two patients underwent 3-T WB-DWI/MRI, 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and CT before diagnostic open laparoscopy (DOL). Imaging findings for tumour characterisation, peritoneal and retroperitoneal staging were correlated with histopathology after DOL and/or open surgery. For distant metastases, FDG-PET/CT or image-guided biopsies were the reference standards. For tumour characterisation and peritoneal staging, WB-DWI/MRI was compared with CT and FDG-PET/CT. Interobserver agreement for WB-DWI/MRI was determined. Results WB-DWI/MRI showed 94 % accuracy for primary tumour characterisation compared with 88 % for CT and 94 % for FDG-PET/CT. WB-DWI/MRI showed higher accuracy of 91 % for peritoneal staging compared with CT (75 %) and FDG-PET/CT (71 %). WB-DWI/MRI and FDG-PET/CT showed higher accuracy of 87 % for detecting retroperitoneal lymphadenopathies compared with CT (71 %). WB-DWI/MRI showed excellent correlation with FDG-PET/CT (κ = 1.00) for detecting distant metastases compared with CT (κ = 0.34). Interobserver agreement was moderate to almost perfect (κ = 0.58–0.91). Conclusions WB-DWI/MRI shows high accuracy for characterising primary tumours, peritoneal and distant staging compared with CT and FDG-PET/CT and may be valuable for assessing operability in ovarian cancer patients. Key Points • Whole - body MRI with diffusion weighting ( WB - DWI / MRI ) helps to assess the operability of suspected ovarian cancer . • Interobserver agreement is good for primary tumour characterisation , peritoneal and distant staging . • WB - DWI / MRI improves mesenteric / serosal metastatic spread assessment compared with CT and FDG - PET / CT . • Retroperitoneal / cervical - thoracic nodal staging using qualitative DWI criteria was reasonably accurate . • WB - DWI / MRI and FDG - PET / CT showed the highest diagnostic impact for detecting thoracic metastases .