RESUMEN
Objective To explore the feasibility of blood oxygen level-dependent (BOLD) MRI to detect the chronic hepatitis b-induced early kidney injury. Methods Seventeen clinically diagnosed chronic hepatitis b patients with early kidney injury and 10 healthy volunteers were enrolled in this preliminary study. The 17 patients underwent dynamic nuclear renography and then subdivided into stage 1 kidney injury group (n=7) and stage 2 kidney injury group (n=10). All of the enrolled subjects underwent BOLD examination and T2* relaxation rates (R2*) of renal cortex and medulla of split kidney, and the ratio between them (R2*med/cor) were measured separately. One-way analysis of variance (ANOVA) were performed on the control group and chronic hepatitis b patients group (kidney injury stage 1 and stage 2 group) to compare the difference of renal cortical and medullary R2*values and R2*med/cor ratio. ROC curves were used to evaluate the efficacy of renal cortical and medullary R2* values and R2*med/cor ratio to diagnose the chronic hepatitis b-induced kidney injury. Results The cortical R2*values of control group, stage 1 kidney injury group and stage 2 kidney injury group were(16.87 ± 0.74)/s,(17.88 ± 0.73)/s,(20.29 ± 2.87)/s, respectively;the medullar R2*values of control group, stage 1 kidney injury group and stage 2 kidney injury group were (28.07±1.03)/s,(31.14±2.49)/s,(32.81±3.28)/s, respectively;R2*med/cor of the of control group, stage 1 kidney injury group and stage 2 kidney injury group were 1.67 ± 0.09, 1.75 ± 0.16, 1.63 ± 0.13, respectively, and the differences among the three groups were statistically significant (F values were 17.779, 19.170 and 3.439 , all P<0.05). Furthermore, the renal cortical and medullary R2* values of chronic hepatitis b patients were significantly higher than the control group, and the the renal cortical R2* value of the patients in stage 2 kidney injury group was also higher than the stage 1 kidney injury group. The area under curve (AUC) of ROC of the renal cortical and medullary R2*values and R2*med/cor to diagnose chronic HBV hepatitis-induced early kidney injury were 0.903, 0.949 and 0.526, respectively. Conclusion It's feasible and has great value to use renal BOLD MRI for the diagnosis of chronic hepatitis b-induced early kidney injury, and the renal cortex is more sensitive than the medulla to the kidney injury.