Abstract: TH-PO102

Diffusional Kurtosis Imaging in Assessing Renal Function and Pathology of IgA Nephropathy: A Preliminary Clinical Study

Session Information

Category: Glomerular

  • 1004 Clinical/Diagnostic Renal Pathology and Lab Medicine

Authors

  • Liu, Yan, Chinese Academy of Medical Science, Peking Union Medical College Hospital, Beijing, China
  • Zhang, Gu-Mu-Yang, Chinese Academy of Medical Science, Peking Union Medical College Hospital, Beijing, China
  • Peng, Xiaoyan, Chinese Academy of Medical Science, Peking Union Medical College Hospital, Beijing, China
  • Sun, Hao, Chinese Academy of Medical Science, Peking Union Medical College Hospital, Beijing, China
  • Chen, Limeng, Chinese Academy of Medical Science, Peking Union Medical College Hospital, Beijing, China
Background

Renal fibrosis is the strongest predictor of ESRD in IgA nephropathy, but noninvasive and repeatable imaging markers are missing. Magnetic resonance imaging (MRI) has higher range of applications in renal parenchyma diseases, and diffusion kurtosis imaging (DKI) is a new promising noninvasive method of MRI which can potentially provide more information about non-Gaussian diffusion using a polynomial model, but still not used to assess renal fibrosis. This study first applied this novel technique to evaluate renal fibrosis, compared with pathological findings of kidney in patients with IgAN.

Methods

Twenty patients with biopsy-proven IgAN were enrolled and divided into two groups (eGFR≥45ml/min and eGFR<45ml/min). The clinical data were documented, and DKI was performed on a clinical 3T MR scanner. Region-of-interest (ROI) measurements were performed to determine apparent diffusion coefficient (ADC), mean kurtosis (MK) and mean diffusivity (MD) of the cortex of the kidneys. Renal biopsy specimens were scored based on the severity of renal fibrosis. The values of DKI metrics were compared between two groups and the association between DKI data and clinicopathologic data were investigated.

Results

Twenty patients consisted of 9 males and 11 females with mean age of 34.6±13.0 years. The pathologic indicators showed significant correlation with eGFR. In DKI model, both renal ADC and MK values not only correlated well with eGFR (ADC: r=0.713,p=0.000; MK: r=-0.622, p=0.003), but also significantly associated with glomerular sclerosis index (GSI) (ADC: r=-0.577, p=0.008; MK: r=0.634, p=0.003) and the percentage of tubular atrophy/interstitial fibrosis (TAIF) (ADC: r=-0.699, p=0.001; MK: r=0.611, p=0.004). The ADC and MK values between two groups were also significantly different (p=0.002 and p=0.007, respectively). But the MD values showed no correlation with all clinicopathologic features and no significant differences were found in MD values between two groups. Further multiple linear regression analysis showed that only eGFR and ADC values was related and only glomerular sclerosis index (GSI) and MK values was related.

Conclusion

Renal ADC and MK values obtained from DKI showed significant correlation with pathologic sclerosis scores of IgAN, could be a promising noninvasive technique in patients follow-up.