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Abstract: TH-PO1127

Diffusion Weighted Imaging for Quantification of Cyst Volume in ADPKD

Session Information

Category: CKD (Non-Dialysis)

  • 1902 CKD (Non-Dialysis): Clinical, Outcomes, and Trials

Authors

  • Caroli, Anna, Mario Negri Institute, Bergamo, Italy
  • Brambilla, Paolo, ASST Papa Giovanni XXIII, Bergamo, Italy
  • Sironi, Sandro, University Milano-Bicocca, Milano, Italy
  • Remuzzi, Giuseppe, IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Bergamo, Italy
  • Remuzzi, Andrea, University of Bergamo, Dalmine, Italy
Background

In autosomal dominant polycystic kidney disease (ADPKD), kidney enlargement is mainly due to cyst growth and associates with renal function decline. Whilst total kidney volume is quite easy to be quantified, total cyst volume (TCV) is difficult and time consuming. In the last decades a number of different magnetic resonance imaging (MRI) modalities have been proposed to investigate renal structure, microstructure, and function. This study proposes a novel method to automatically quantify TCV in ADPKD patients using diffusion weighted MRI (DWI).

Methods

T2-weighted MRI and DWI (Figure 1A) were performed in 15 patients with ADPKD enrolled in the EuroCYST Initiative in Bergamo Hospital (Italy). TCV was quantified on each T2-weighted MRI using an accurate semi-automated method assumed as reference [Caroli et al. Lancet 2013]. Each DWI was processed using a bi-exponential model. The histogram of the pure diffusion component (D) was thresholded using the Otsu method, to separate cyst from non-cystic renal parenchyma, and TCV was automatically computed based on this threshold. DWI-computed TCVs were finally compared with the reference values.

Results

Fluid-filled kidney cysts were denoted by higher D values than non-cystic volume (Figure 1B). DWI-computed TCV highly and significantly correlated with TCV quantified on T2-weighted MRI (rho = 0.99, p <0.001)(Figure 1C), despite the former consistently underestimating TCV (DWI-computed TCV = 1144±1068 mL; reference T2-weighted TCV = 1356±1256 mL).

Conclusion

Current findings suggest that our method can be used to automatically quantify TCV on DWI to accurately estimate the extension of renal structural changes in ADPKD. The proposed method may be useful to monitor disease progression as well as to evaluate the effect of pharmacological intervention.

Acknowledgements. This study was funded in part by ERA – EDTA (EuroCYST Initiative).

Funding

  • Private Foundation Support