 Original Contribution COMPARISON OF SHEAR WAVE ELASTOGRAPHY AND CONVENTIONAL ULTRASOUND IN ASSESSING KIDNEY FUNCTION AS MEASURED USING 51 CR- ETHYLENEDIAMINETETRAACETIC ACID AND 99 TC-DIMERCAPTOSUCCINIC ACID TAGGEDPSOOK SAM LEONG,* ,y JEANNIE HSIU DING WONG,* ,z MOHAMMAD NAZRI MD SHAH,* ,z ANUSHYA VIJAYANANTHAN,* ,z MAISARAH JALALONMUHALI, x and KWAN HOONG NG* ,z TAGGEDEND * Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia; y Department of Biomedical Imaging, University of Malaya Medical Centre, Kuala Lumpur, Malaysia; z University of Malaya Research Imaging Centre, University of Malaya, Kuala Lumpur, Malaysia; and x Department of Medicine, University of Malaya, Kuala Lumpur, Malaysia (Received 10 August 2018; revised 25 January 2019; in final from 28 January 2019) Abstract—The purpose of this study was to assess the potential of shear wave elastography (SWE) as an indicator of abnormal kidney function defined by radiolabeled glomerular filtration rate (GFR). Fifty-seven patients referred for 51 Cr-ethylenediaminetetraacetic acid GFR and 99m Tc-dimercaptosuccinic acid renal scintigraphy were included. Young’s modulus (YM) measured with SWE and kidney length, volume, cortical thickness and parenchymal echogenicity measured with conventional ultrasound were correlated with patients’ GFR and renal scintigraphy results. Spearman correlation coefficients between SWE and GFR were negative for the right (r = 0.635, p < 0.0001) and left (r = 0.817, p < 0.0001) kidneys. 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 cor- rectly predicted the dominant functioning kidney in 94.7% of cases. The area under the receiver operating char- acteristic curve for SWE (0.800) was superior to that for conventional ultrasound (0.2520.415). The cutoff value of 5.52 kPa suggested a kidney function 60 mL/min/1.73 m 2 (82.4% sensitivity and 76.2% specificity). SWE has advantages over conventional ultrasound in assessing kidney function and distinguishing the dominant functioning kidney. (E-mail: mnazri@ummc.edu.my) © 2019 World Federation for Ultrasound in Medicine & Biology. All rights reserved. Key Words: Conventional ultrasound, 51 Cr-ethylenediaminetetraacetic acid glomerular filtration rate, Glomeru- lar filtration rate, Shear wave elastography, Stiffness, 99m Tc-dimercaptosuccinic acid renal scintigraphy. INTRODUCTION The kidneys are important for regulating ions and fil- tering metabolite waste from blood. Delayed detection of renal impairment may lead to chronic kidney dis- ease (CKD), which may eventually result in renal fail- ure. Approximately 9% of adults in the United States are estimated to have CKD (Levey et al. 2007), and several studies have also reported a high prevalence in Australia and Asia (Chen et al. 2005; White et al. 2010). As such, accurate measurements of kidney function are useful to diagnose the disease and arrest its progression. Currently, glomerular filtration rate (GFR) obtained using radioactive markers, such as chromium-51-labeled ethylenediaminetetraacetic acid ( 51 Cr-EDTA), are the standard reference to determine kidney function (Fleming et al. 1991). Besides radiola- beled GFR, individual relative kidney function can also be determined using static renal scintigraphy, with technetium-99m-labeled Dimercaptosuccinic acid ( 99m Tc-DMSA) as the marker. Practical usage of these markers is limited because these markers are radioactive and could be hazardous and because they are difficult and time consuming to administer, as well as unavailable in most hospitals. Therefore, estimated GFR (eGFR) formulas have been developed based on serum creatinine concentration, race, age and gender (Levey et al. 2009). The eGFR is less accurate for patients at the extremes in body mass and can be influenced by dietary protein intake, muscle mass and muscle injury (Baxmann et al. 2008). As such, eGFR measurements are hampered by substantial error Address correspondence to: Mohammad Nazri Md Shah, Depart- ment of Biomedical Imaging, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. E-mail: mnazri@ummc.edu.my 1417 Ultrasound in Med. & Biol., Vol. 45, No. 6, pp. 14171426, 2019 Copyright © 2019 World Federation for Ultrasound in Medicine & Biology. All rights reserved. Printed in the USA. All rights reserved. 0301-5629/$ - see front matter https://doi.org/10.1016/j.ultrasmedbio.2019.01.024