Imaging plays a critical role in the assessment of patients with rectal cancer, and positron emission tomography/magnetic resonance imaging (PET/MRI) has shown superiority in specific clinical scenarios. This review describes the potential contribution of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET/MRI relative to standard of care imaging—computed tomography (CT), MRI, or PET/CT—in the evaluation of patients with rectal cancer in settings such as primary staging, treatment response assessment, and recurrence detection. We discuss ¹⁸F-FDG PET/MRI protocols and clinical workflow, as well as highlighting the potential clinical superiority of PET/MRI over other imaging modalities.

Keywords: Positron-emission tomography; Magnetic resonance imaging; Rectal neoplasms