Comparison of resistive index and shear-wave elastography in the evaluation of chronic kidney allograft dysfunction

Ameet Kumar Jesrani; Syed M Faiq; Rahma Rashid; Tariq Ali Kalwar; Rehan Mohsin; Tahir Aziz; Nida Amin Khan; Muhammed Mubarak

doi:10.5500/wjt.v14.i1.89255

Comparison of resistive index and shear-wave elastography in the evaluation of chronic kidney allograft dysfunction

World J Transplant. 2024 Mar 18;14(1):89255. doi: 10.5500/wjt.v14.i1.89255.

Authors

Ameet Kumar Jesrani¹, Syed M Faiq¹, Rahma Rashid², Tariq Ali Kalwar³, Rehan Mohsin⁴, Tahir Aziz³, Nida Amin Khan¹, Muhammed Mubarak⁵

Affiliations

¹ Department of Radiology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan.
² Department of Pathology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan.
³ Department of Transplantation, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan.
⁴ Department of Urology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan.
⁵ Department of Pathology, Sindh Institute of Urology and Transplantation, Karachi 74200, Sindh, Pakistan. drmubaraksiut@yahoo.com.

Abstract

Background: Detection of early chronic changes in the kidney allograft is important for timely intervention and long-term survival. Conventional and novel ultrasound-based investigations are being increasingly used for this purpose with variable results.

Aim: To compare the diagnostic performance of resistive index (RI) and shear wave elastography (SWE) in the diagnosis of chronic fibrosing changes of kidney allograft with histopathological results.

Methods: This is a cross-sectional and comparative study. A total of 154 kidney transplant recipients were included in this study, which was conducted at the Departments of Transplantation and Radiology, Sindh Institute of Urology and Transplan tation, Karachi, Pakistan, from August 2022 to February 2023. All consecutive patients with increased serum creatinine levels and reduced glomerular filtration rate (GFR) after three months of transplantation were enrolled in this study. SWE and RI were performed and the findings of these were evaluated against the kidney allograft biopsy results to determine their diagnostic utility.

Results: The mean age of all patients was 35.32 ± 11.08 years. Among these, 126 (81.8%) were males and 28 (18.2%) were females. The mean serum creatinine in all patients was 2.86 ± 1.68 mg/dL and the mean estimated GFR was 35.38 ± 17.27 mL/min/1.73 m². Kidney allograft biopsy results showed chronic changes in 55 (37.66%) biopsies. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SWE for the detection of chronic allograft damage were 93.10%, 96.87%%, 94.73%, and 95.87%, respectively, and the diagnostic accuracy was 95.45%. For RI, the sensitivity, specificity, PPV, and NPV were 76.92%, 83.33%, 70.17%, and 87.62%, respectively, and the diagnostic accuracy was 81.16%.

Conclusion: The results from this study show that SWE is more sensitive and specific as compared to RI in the evaluation of chronic allograft damage. It can be of great help during the routine follow-up of kidney transplant recipients for screening and early detection of chronic changes and selecting patients for allograft biopsy.

Keywords: Biopsy; Chronic allograft changes; Histopathology; Resistive index; Shear wave; Sonoelastography.