Comparison between whole-body MRI with diffusion-weighted imaging and PET/CT in staging newly diagnosed FDG-avid lymphomas

Objectives To compare whole body-MRI (WB-MRI) with diffusion-weighted imaging and FDG-PET/CT in staging newly diagnosed FDG-avid lymphomas. Methods 68 patients (37 males, 31 females; median age 42 years; range 15-86 years) with histologically confirmed lymphoma (37 Classical Hodgkin, 16 Diffuse large B-cell, 10 Follicular, 5 Mantle cell) underwent both MRI and FDG-PET/CT before treatment. Ann Arbor stages obtained with WB-MRI and FDG-PET/CT were compared using Cohen's k statistics. Moreover WB-MRI and FDG-PET/CT stages were compared with the pathological stages obtained after the diagnostic ITER using also bone marrow and available biopsies if clinically indicated. Results The agreement between WB-MRI and FDG-PET/CT was excellent. WB-MRI stage was equal to those of FDG-PET/CT in 62/68 patients (91.2%). There was an excellent agreement between WB-MRI stage and pathological stage (63/68 patients; 92.6%), and between FDG-PET/CT and pathological stage (64/68 patients; 94.1%). The differences between the stages were more frequent in the patients with Mantle cell lymphoma. Conclusions WB-MRI can be considered as a promising technique for FDG-avid lymphoma staging.