Prognosis Prediction in Initially Diagnosed Multiple Myeloma Patients Using Intravoxel Incoherent Motion‐Diffusion Weighted Imaging and Multiecho Dixon Imaging

Background Multiparametric MRI provides complementary information for the diagnosis and management of multiple myeloma (MM). Purpose To evaluate the association of prognostic factors of MM and parameters derived from intravoxel‐incoherent motion diffusion‐weighted imaging (IVIM‐DWI) and multiecho (ME) Dixon. Study Type Retrospective. Population In all, 78 MM patients. Field Strength/Sequences T 1 ‐weighted turbo spin‐echo sequences (TSE), IVIM‐DWI, ME 3D gradient echo sequence with multistep adaptive fitting at 3T. Assessment The region of interest (ROI) on the vertebral body was independently measured on four parametric maps (D slow , D fast and perfusion fraction [ f ], and proton‐density fat‐fraction [Ff] maps) by two readers. All patients were categorized into three groups based on the International Staging System (ISS). Statistical Tests Three groups were compared using analysis of variance (ANOVA) and post‐hoc tests with Bonferroni correction. Logistic regression analysis was performed to predict the advancement of disease (early vs. advanced). Principal component analysis (PCA) was used to find the deterministic parameters. Results D slow and Ff were significantly different among ISS‐1 ( n = 38), ISS‐2 ( n = 22), and ISS‐3 ( n = 18) groups in both readers: 0.36, 0.41, and 0.58 × 10 −3 mm 2 /s for D slow ( P < 0.05), and 46%, 30%, and 15% for Ff ( P < 0.05) in reader 1; 0.34, 0.41, and 0.58 × 10 −3 mm 2 /s for D slow ( P < 0.05), 43%, 27%, and 13.2% for Ff ( P < 0.05) in reader 2, respectively. D fast between ISS‐3 and the other groups was significantly different in one reader only: 2.03, 2.29, and 2.85 × 10 −3 mm 2 /s ( P < 0.05). There was no significant difference in f among the groups in both readers. Logistic regression by stepwise selection indicated Ff as the single most significant factor for differentiating early and advanced stages of MM with an accuracy of 76% and area under the curve (AUC) of 0.83 ( P < 0.05). PCA revealed Ff, and D slow as the deterministic parameters, with a cumulative proportion of 0.84. Data Conclusion D slow and Ff are associated with the prognostic factor of MM. Level of Evidence 3 Technical Efficacy Stage 5. J. MAGN. RESON. IMAGING 2021;53:491–501.