Functional MR imaging of kidneys in patients with lupus nephritis / 中华肾脏病杂志

ABSTRACT

Objective To evaluate the functional magnetic resonance (MR) imaging in the assessment of renal involvement and pathological changes in patients with lupus nephritis (LN).Methods Seventeen patients with LN and 10 healthy controls underwent coronal echo-planar diffusion-weighted (DW) MR imaging and blood oxygen level dependent (BOLD) MR imaging of the kidneys with a single breath-hold time of 16 s.The apparent diffusion coefficient (ADC) and R2* value of the kidneys were calculated with high b values (b=500 s/mm2).The correlation between the renal injury variables and the ADCs or R2* values was evaluated.Results The mean ADC value of kidneys in patients with LN was (2.43+0.24)×10-3 mm2/s,the mean R2* values of the renal cortex and medulla were (11.72+2.35)/s and (13.07+2.35)/s respectively,which were all significantly lower than those in volunteers (P=0.045,P=0.048and P=0.001,respectively).In the patients with LN,the mean ADC values were positively correlated with estimated glomerular filtration rate (eGFR) (r=0.558,P＜0.05).There was a negative correlation between the ADC values of the right kidneys and pathological chronic indexes (r=-0.493,P＜0.05).Moreover,the R2*values of the renal medulla were negatively correlated with 24 hours proteinuria,serum creatinine,pathological active indexes.The patients were assigned to group A (class Ⅲ,Ⅳ,Ⅴ,n=8) and group B class Ⅴ + Ⅲ and Ⅴ + Ⅳ,n=9).The tubulointerstitial lesions in group B were more severe than those in group A,while the mean ADC values and R2* values of the renal cortex in group B were lower as compared to group A.Conclusion DW MR imaging and BOLD MR imaging may be used to non-invasively monitor the disease activity and evaluate the efficacy in lupus nephritis.