The Clinical Study Of Multiple B Value Diffusion Weighted Imaging In Chronic Kidney Disease

Objective:To investigate the link between different parameters and the changes of function and structure of chronic kidney disease(CKD) by using multiple b value diffusion-weighted imaging(DWI). And then assessing the clinical value of multiple b value DWI in diagnosing CKD.Materials and methods:76 patients underwent multiple b value DWI examination during March,2015 to December,2015.35 healthy volunteers are divided into the control group.41 patients suffering from CKD are divided into experimental group, which includes 12 patients underwent renal needle biopsy. According to CKD stage, patients were divided into two subgroups. One subgroup means the early stage of renal damage, namely CKD stage 1 and 2. The other means the middle and latestage of renal damage, namely CKD stage 3 and 4. Katafuchi score was used to assess the renal function of patients underwent renal needle biopsy.GE Signa HDxt 3.0T MRI Scanner was utilized in our study. Conventional MRI sequence: FSE-T2 WI transection and coronary position, FSE-T1 WI transection. Multiple b value DWI sequence: respiratory gated scan. We measured the parameters of multiple b value DWI of cortex and medulla part of both kidneys to compare the differences between control group and two subgroups. The correlation between parameters of patients underwent renal needle biopsy and pathological indexes. Data were analyzed statistically by using SPSS 19.0 software. And all measurement data were tested for normal distribution and homogeneity of variance. As well, T test, variance analysis and Spearman correlation analysis were used in our study. P<0.05 for the difference was statistically significant.Results:1. Comparison between control group and all experimental groups.The difference of parameters ADCstan、D、D*、f and DDC between control group and experimental group was statistically significant(P<0.05). Though value of parameters of the cortical part is higher than that of the medulla part, no singificans was found(P=0.964). For the same patient, no matter in the control group or experimental group, there were no obvious differences in the parameters of the left and right kidneys(P>0.05).2. Comparison between control group and subgroups.Compared with the control group, value of parameters D*、f and DDC in renal cortex showed a decline in subgroup one, which was statistically significant(P<0.05). As well, value of parameters D* and f in renal medulla showed a decline in subgroup one, which was statistically significant(P<0.05). For subgroup two, value of parameters ADCstan、D、D* and DDC in renal cortex and parameters D in renal medulla made significant differences(P<0.05) compared with that of the control group. No obvious differences were found in other parameters between control group and subgroups(P>0.05).3. Comparison between subgroup one and subgroup two.Value of the parameters ADCstan and D* in renal cortex in subgroup two showed a decline and value of the patameter DDC showed an increase in renal medulla, which were both statistically significant(P<0.05). Other parameters between two subgroups presented no statistical differences(P>0.05).4. Correlation analysis.The D value in renal cortex of biopsy patients was negatively correlated with the total score of pathological lesion, the integral of the glomerular, the integral of the renal tubule and the integral of the small vessel(r value was-0.900、-0.940、-0.735 and-0.717 successively), which was statistically significant. Similarly, the D* value(r value was-0.691 and 0.777) and the DDC value(r value was-0.878、-0.929 and-0.682) were also negatively correlated with the scores above, which was statistically significant. However, value of ADCstan、f and a showed no significant correlation with the scores above.Conclusions:1. Parameters from multiple b value DWI revealed the differences of function and structure between cortex and medulla part of the kidney.2. Value of parameters D* and f in renal medulla can provide evidence for the early diagnosis of chronic kidney disease.3. ADCstan and D* value of the renal cortex may have a certain clinical value for the evaluation of CKD course.4. In some degree, value of parameters D、D* and DDC can reflect the degree of pathological damage in CKD patients, which is expected to become a noninvasive mean of evaluation of CKD pathological change, guide treatment and long-term follow-up.