Sook Sam Leong
University of Malaya Medical Centre, Malaysia
Title: Comparison of shear-wave elastography and conventional ultrasound in assessing kidney function as measured using 51-chromium-EDTA and 99-technetium DMSA
Biography
Biography: Sook Sam Leong
Abstract
Glomerular Filtration Rate (GFR) obtained using radioactive markers are the standard reference to determine kidney function. However the practical usage of these markers is limited due to radiation hazard. One potential marker that has gained interest is tissue elasticity, evaluated using Shear-Wave Elastography (SWE). The purpose of this study was to assess the potential of using SWE as an indicator to detect abnormal kidney function defined by radiolabelled GFR. 57 patients referred for 51Cr-ethylenediaminetetraacetic acid GFR and 99mTc-dimercaptosuccinic acid renal scintigraphy were included. Young’s Modulus (YM) measurement from SWE and kidney length, volume, cortical thickness and parenchymal echogenicity from conventional ultrasound data were correlated with patients' GFR and renal scintigraphy results. Spearman correlation coefficients showed negative correlation between SWE and GFR for the right (r= -0.635, p<0.0001) and left kidneys (r= -0.817, p<0.0001). Positive correlations between left renal cortical thickness (r=0.381, p=0.04) and left kidney volume (r=0.356, p=0.019) with GFR were reported. SWE correctly predicts the dominant functioning kidney in 94.7% of cases. The area under the ROC curve for SWE (0.800) was superior to conventional ultrasound (0.252-0.415). The cut-off value ³5.52 kPa suggested a kidney function £60 ml/min/1.73 m2 (82.4% sensitivity and 76.2% specificity). SWE imaging has advantages over conventional ultrasound in assessing kidney function as well as identifying which kidney of the two has the lower function based on renal parenchymal stiffness.