Whole-body MRI, including diffusion-weighted imaging, for staging lymphoma: comparison with CT in a prospective multicenter study.

Purpose: To compare whole-body magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), to computed tomography (CT) for staging newly diagnosed lymphoma. Materials and Methods: In all, 108 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI (T1-weighted and T2-weighted short inversion time inversion recovery [n = 108], and DWI [n = 104]) and CT. Ann Arbor stages were assigned according to whole-body MRI and CT findings. Staging disagreements were resolved using bone marrow biopsy, FDG-PET, and follow-up studies. The results were descriptively analyzed. Results: Staging results of whole-body MRI without DWI were equal to those of CT in 66.6%, higher in 24.1%, and lower in 9.3%, with correct/incorrect/unresolved higher staging and incorrect/unresolved lower staging relative to CT in 15/7/4 and 9/1 patient(s), respectively. Staging results of whole-body MRI with DWI were equal to those of CT in 65.4%, higher in 27.9%, and lower in 6.7%, with correct/incorrect/unresolved higher staging and incorrect/unresolved lower staging relative to CT in 18/6/5 and 6/1 patient(s), respectively. Conclusion: The results of this study suggest that whole-body MRI staging equals CT staging in the majority of patients with newly diagnosed lymphoma. No advantage of additional DWI was demonstrated. Whole-body MRI can be a good alternative to CT if radiation exposure should be avoided.