ObjectivesTo determine the value of 18F-FDG-PET/MRI in the diagnosis and management of patients with pelvic recurrence of rectal cancer.MethodsForty-four patients (16 women, 28 men) with a history of rectal cancer who received FDG-PET/MRI between June 2011 and February 2017 at our institution were retrospectively enrolled. Three patients received two FDG-PET/MRIs; thus a total of 47 examinations were included. Pelvic recurrence was confirmed either with histology (n = 27) or imaging follow-up (n = 17) (> 4 months). Two readers (one radiologist, one nuclear medicine physician) interpreted the images in consensus. Pelvic lesions were assessed regarding FDG uptake and morphology. Sensitivity, specificity, positive and negative predictive values as well as accuracy of PET/MRI in detecting recurrence were determined …