~ 86 ~ International Journal of Radiology and Diagnostic Imaging 2021; 4(2): 86-91 E-ISSN: 2664-4444 P-ISSN: 2664-4436 www.radiologypaper.com IJRDI 2021; 4(2): 86-91 Received: 04-02-2021 Accepted: 06-03-2021 Dr. Sonal Agrawal MBBS, MD Radiodiagnosis, Post Graduate, Department of Radiodiagnosis, JSS Medical College and Hospital, Mysore, Karnataka, India Dr. Nagaraj Murthy MBBS, MD Radiodiagnosis, JSS Medical College and Hospital, Mysore, Karnataka, India Dr. Manjunath Shetty MBBS, MD, DM Nephrology; Professor & Head, Department of Nephrology, JSS Medical College and Hospital, Mysore, Karnataka, India Dr. Rudresh Hiremath MBBS, MD, DNB, EDIR, Professor & Head, Department of Radiodiagnosis, JSS Medical College and Hospital, Mysore, Karnataka, India Corresponding Author: Dr. Sonal Agrawal MBBS, MD Radiodiagnosis, Post Graduate, Department of Radiodiagnosis, JSS Medical College and Hospital, Mysore, Karnataka, India Shear wave elastography in transplant kidney and its correlation with renal doppler parameters and eGFR Dr. Sonal Agrawal, Dr. Nagaraj Murthy, Dr. Manjunath Shetty and Dr. Rudresh Hiremath DOI: http://dx.doi.org/10.33545/26644436.2021.v4.i2b.202 Abstract Chronic allograft nephropathy is the most common cause of graft failure and is characterized by interstitial fibrosis and tubular atrophy, this study evaluated the role of shear-wave sonoelastography in the differentiation of stable renal allograft from allograft dysfunction & establish the correlation of parenchymal stiffness values with resistive index (RI), serum creatinine level, estimated glomerular filtration rate (eGFR). A prospective study of 40 patients who had undergone renal transplantation was conducted between October 2018 and July 2020. Patients were classified as having stable allograft and allograft dysfunction on the basis of clinical parameters practised in our institution. Receiver operating characteristic curve were drawn to obtain a cut off value with maximum sensitivity and specificity. Pearson’s correlation was used to evaluate different renal parameters and their correlation with the shear wave elastography (SWE) value. In this study 27 patients had graft dysfunction and 13 had stable graft. Use of the threshold value of 8.23kPa for SWE resulted in a sensitivity of 70% and specificity of 100% for the differentiation of stable allograft from allograft dysfunction. Parenchymal stiffness showed inverse correlation with eGFR (r = -.756, P<0.001) and a direct correlation with RI (r- 0.42, P = 0.003) and serum creatinine level (r = 0.76, P<0.001). SWE helps to differentiate stable allograft from allograft dysfunction. The direct correlation with RI & serum creatinine level and inverse correlation of parenchymal stiffness with eGFR show that SWE reflects functional status of the renal allograft. Keywords: chronic allograft rejection, interstitial fibrosis, shear wave elastography (SWE), resistive index (RI), estimated glomerular filtration rate (eGFR) Introduction With increase in number of end stage renal disease, rate of renal transplant is increasing as it is more cost effective in long term and less traumatic with improved life quality as compared to haemodialysis. However, renal allograft loss due to chronic rejection is a major problem which often presents as progressive and insidious allograph dysfunction characterized by slow loss of renal function. Currently, biopsy remains the gold standard for assessing renal allograft dysfunction, including estimating fibrosis. Being an invasive process, it is not routinely done until patient starts to show features of failure like rise in serum creatinine or proteinuria. However, biopsy remains an imperfect standard, with limitations and inherent risks, including sampling errors, allograft trauma sustained with multiple needle pass attempts, and large interobserver variation in interpreting biopsy samples among pathologists. Furthermore, biopsy is neither reasonable nor feasible for every fluctuation in the renal allograph status. Complications of biopsy include bleeding (ranging from gross haematuria to perirenal hematomas), arteriovenous fistula formation, infection, and pseudoaneurysms [1] . Chronic rejection term has been replaced with more histologically descriptive term “interstitial fibrosis and tubular atrophy” and often presents as progressive and insidious allograph dysfunction characterized by a slow loss of renal function. It may manifest as new or worsening hypertension, an increasing serum creatinine level, a down trending estimated glomerular filtration rate, or proteinuria [2-4] . Unfortunately, serum indicators of declining renal function often lag behind actual graft damage, at which point the injury may be irreversible [1] .