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 (D_f ), molecular diffusion coefficient (D_s ), perfusion fraction (f), ADC_s , α, ADC_k , 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 D_s 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.