Multiparameter diffusion‐weighted imaging for characterizing pathological patterns in lupus nephritis patients: A preliminary study

Background Microstructural changes of lupus nephritis (LN) kidney such as inflammatory cell infiltration or fibrosis could influence water molecular movement or diffusion, which indicates that diffusion‐weighted imaging (DWI) may become a valuable tool in evaluation of this disease. Purpose To explore whether multiparameter diffusion‐weighted imaging (mDWI) could contribute to characterize pathological patterns in LN patients. Study Type Retrospective. Population Twenty‐two patients with LN. Field Strength/Sequence Multi‐b value DWI was performed with a 3.0 T scanner. Assessment Apparent diffusion coefficient (ADC)m, perfusion‐related diffusion coefficient (Df), molecular diffusion coefficient (Ds), perfusion fraction (f), ADCs, α, ADCk, and mean kurtosis (MK) were calculated by monoexponential, biexponential, stretched‐exponential, and kurtosis models fits, respectively. Statistical Tests Independent sample t‐test, Pearson analysis and receiver operating characteristic (ROC). Results In the whole group, the activity index (AI) correlated significantly with alpha values in the medulla (rho = –0.54, P = 0.03). The chronicity index (CI) correlated significantly with Ds values in the medulla (rho = –0.61, P = 0.02). No significant association was found between any other diffusion parameter and histologic grade with all P > 0.05. For differentiating proliferative LN (Class III or IV) from Class V, the area under the ROC curve (AUC) of alpha in the medulla was 0.833 (P = 0.023). Data Conclusion mDWI might be used for the characterization of pathological patterns in LN patients. Level of Evidence: 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;50:1075–1084.