Abstract: SA-PO334

Noninvasive Evaluation of Microcirculation Disorder, Tubular Injury, and Kidney Fibrosis Using Functional Magnetic Resonance Imaging

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 302 CKD: Estimating Equations, Incidence, Prevalence, Special Populations

Authors

  • Zhang, Jiong, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing China, Nanjing, China
  • Tang, Xiong, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing China, Nanjing, China
  • Zhang, Ming-chao, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing China, Nanjing, China
  • Zhang, Long jiang, Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, Jiangsu, China
  • Liu, Zhi-Hong, National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing China, Nanjing, China
Background

The key contributors to the progression of nearly all forms of CKD are reduced microvascular blood flow, tubular injury and fibrosis. Despite theirs importance, clinicians currently have no means of noninvasively assessing these factors, except historically relied on percutaneous renal biopsy. Recent advances in imaging technology have raised the exciting possibility of MRI. The aim of this study was to evaluate the feasibility of functional MRI for functional assessment of renal morphology and diffusion, tubular injury, also fibrosis burden in CKD.

Methods

Seventy CKD patients were studied. The feasibility of three fRMI sequences, which were diffusion-wighted-imageing (DWI), aquaporins (AQP), and magnetic resonance elastography (MRE) were evaluated to assess kindey microcirculation disorder, tubular injury and scarring burden. Capillary situation was assessed by peritubular capillaries number, which was showed by CD34 staining. Tubular injury was measured by AQP1 staining. Cortex fibrosis was measured by kidney sections stainded with Masson’s trichrome, which were scanned with an Aperio ScanScope system and analyzed using ImageScope.

Results

Functional MRI sequence DWI-ADC showed negative correlation with glomerulosclerosis and cortex fibrosis burden, R2=0.128 and 0.167 respectively, P<0.01. Apparent DWI-ADC cortex values were significantly increased in CKD stage 3 and 4, which were higher than CKD stage 1 (P=0.02). There were no significant relationships with PTCs number per x400 image. AQP1 staining, which stands for AQP in tubular cells, was significantly decreased in later stages (P<0.01). Although, the fMRI-AQP value did not show statistical correlation with renal AQP staining changings in cortex (P=0.796), AQP sequence showed positive correlation with cortex fibrosis burden (R2=0.071, P=0.028). Apparently, MRE60e Hz had negative correlation with glomerulosclerosis and cortex scarring burden in these patients (R2=0.115 and 0.026 respectively, P=0.040 and 0.052). Interestingly, it was showed that MRE values were significantly lower in serious renal fibrosis subgroup than mild group or normal.

Conclusion

In this pioneer study, DWI, AQP and MRE sequence from functional MRI appear to serve as noninvasive evaluation method for evaluating renal microcirculation, tubular injury and fibrosis.