Ultraschall Med 2016; 37 - SL4_4
DOI: 10.1055/s-0036-1587732

Is 2D shear wave elastography (2D-SWE) usefull in the assessment of chronic kidney disease? – A 2 center pilot study

F Bob 1, M Crnogorac 2, I Sporea 1, G Ivanac 3, A Popescu 1, B Brkljačić 3, R Sirli 1, M Crnogorac 3, I Grosu 1, A Schiller 1
  • 1University of Medicine and Pharmacy "Victor Babes" TImisoara, Internal Medicine 2, Timisoara, Romania
  • 2Dubrava University Hospital, Nephrology, Zagreb, Croatia
  • 3Dubrava University Hospital, Clinical Department of Diagnostic and Interventional Radiology, Zagreb, Croatia

Purpose: The results published so far regarding elastography of the kidney (mainly point shear wave speed measurements) are not always consistent. The present study aims to evaluate another elastographic method (2D-SWE, Aixplorer, Supersonic Imagine), performed independently in two centers.

Material and methods: The study was performed in two Nephrology Clinics from Croatia and Romania on a total of 58 subjects (33 female, 25 male; mean age 45.5 ± 17.4) – 46 with chronic kidney disease (CKD) and 12 healthy volunteers. In all patients kidney shear wave speed (KSWS) values were determined using the 2D-SWE method. We tried to obtain 5 valid measurements in each kidney, with the patient in lateral decubitus, median values were calculated and expressed in meters/second (m/s).

Results: Valid KSWS values were obtained in 96.5% of the subjects for the left kidney, but in only 77.5% of the subjects for the right kidney, therefore we chose to use the results obtained in the left kidney. We found significantly higher KSWS values in male vs. female subjects (5.3 vs. 3 m/s, p = 0.01), and in patients compared to normal controls (4.6 vs. 1.7 m/s, p = 0.005). We found a significant indirect correlation between KSWS and glomerular filtration rate (eGFR) (r =-0.31, p = 0.03), but no correlation was found with measurement depth, age, proteinuria or with histological parameters obtained from renal biopsy (tubulo-interstitial fibrosis, arteriolar hyalinosis). We found a statistically significant difference between the results obtained in the two centers (p < 0.001).

Conclusion: KSWS measured using 2D-SWE is difficult to perform due to the inhomogeneity of the renal parenchyma, fact that probably leads to significant differences between results obtained on subjects assessed in two independent centers. KSWS is increasing with the progression of renal disease (decrease in eGFR), but there is no correlation with renal fibrosis, so probably other factors influence kidney stiffness.