Measurement of Intra-Renal Resistive Index by Spectral Doppler Ultrasound for Early Detection of Diabetic Nephropathy

Author(s): Anika Mahfuz, Saieef Zaman, Kazi Shantono Saiham, Md. Immam Hossin, S M Yunus Ali, Kamrun Nahar, Md. Rasel Ahmad

Background: Diabetic nephropathy (DN) is a major cause of end-stage renal disease and is closely associated with long-term poor control of diabetes. Early detection is essential to halt the progression of diabetic nephropathy. Aim: The aim of the present study is to assess the ability of renal resistive index in differentiating patients with diabetes mellitus with long duration of diabetes, who have diabetic nephropathy. Results: Fiftyseven patients (mean age 56.39 ± 8.54 years) were included in the study. Diabetic nephropathy was observed in 82.5%, the proportion being slightly higher among men 88.9% than women 76.7%. In addition, intrarenal resistive index (RI) bilaterally was elevated in the majority of patients RI > 0.7 reflecting increased intrarenal vascular resistance. High RI had a close agreement 89.4% with biochemical evidence of nephropathy. The intrarenal RI proved its strong validity 90% sensitivity, 70% specify, 87% accuracy and a positive predictive value of 93% as a noninvasive method in the pre-clinical assessment of overt diabetic nephropathy. Materials and Methods: This cross-sectional observational study was performed in the Department of Radiology and Imaging, Sir Salimullah Medical College Hospital, Dhaka from January 2023 to December 2024. A group of 57 men and women selected according to strict inclusion/exclusion criteria. The study was approved by the institutional review board and adhered to ethical guidelines outlined in the Declaration of Helsinki. All patients underwent an evaluation of the intrarenal resistive index (RI) by spectral Doppler ultrasound. Statistical analyses were done with the aid of SPSS software (version 26), and all values are expressed as mean ± SD where applicable statistical tests were used. Conclusion: Spectral Doppler ultrasonography has a good sensitivity and specificity in estimating the RI. RI is a reliable and non-invasive detector for diabetic nephropathy. It is simple, safe, reliable and cost-effective and may be convenient for general screening of early diabetic nephropathy.