Differentiation of focal indeterminate marrow abnormalities with multiparametric MRI

Purpose To explore magnetic resonance imaging (MRI) parameters from intravoxel incoherent motion diffusion‐weighted imaging (IVIM‐DWI), multiecho Dixon imaging (ME‐Dixon), and dynamic contrast‐enhanced imaging (DCE) for differentiating focal indeterminate marrow abnormalities Materials and Methods Forty‐two patients with 14 benign and 28 malignant focal marrow abnormalities were included. The following were independently analyzed by two readers: signal intensity (SI), contour, and margin on conventional MR images; SI on b‐800 images (SIb‐800), apparent diffusion coefficient (ADC), IVIM parameters (Dslow, Dfast, and f), fat fraction (Ff), and DCE parameters (time‐to‐signal intensity curve pattern, iAUC, Ktrans, kep, and ve). The MR characteristics and parameters from benign and malignant lesions were compared with a chi‐squared test and the Mann–Whitney U‐test, respectively. The area under receiver operating characteristic (ROC) curves (AUC) of each sequence were also compared. Interobserver agreements were assessed with Cohen's κ, and intraclass correlation coefficient (ICC). Results ADC, Dslow, and Ff demonstrated a significant difference between benign and malignant marrow abnormalities for both readers (P < 0.001). SIb‐800 and perfusion‐related parameters from IVIM‐DWI and DCE were not significantly different between the two groups (P = 0.145, 0.439, and 0.337 for reader 1, P = 0.378, 0.368, and 0.343 for reader 2, respectively). The AUCs of ADC, Dslow, and Ff were significantly higher for differentiating indeterminate marrow abnormalities in both readers (P < 0.001). Interobserver agreements were substantial in SIb‐800, and ICCs were almost perfect for ADC, Dslow, f, and Ff, and substantial for iAUC, kep, Ktrans, ve, and Dfast. Conclusion ADC, Dslow, and Ff may provide information for differentiating focal indeterminate abnormalities. Level of Evidence: 3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:49–60