EVALUATION OF INTRARENAL RESISTIVE INDEX BY DUPLEX COLOR DOPPLER ULTRASONOGRAPHY IN PATIENTS WITH DIABETIC NEPHROPATHY – COMPARISON BETWEEN HEALTHY ADULT CONTROL SUBJECTS
Background: Renal Doppler Ultrasonography (USG) has become a useful adjunct to gray scale sonography in the evaluation of renal function in various pathophysiological conditions like diabetic nephropathy. We can diagnose diabetic nephropathy by serum creatinine level and creatinine clearance rate. But early stage diagnosis of diabetic nephropathy is not always possible. In this study we have focused on resistive index of interlobar arteries of kidney to see changes of renal parenchyma for early stage diagnosis of diabetic nephropathy. Objectives: To observe the difference between values of intrarenal resistive index measured by duplex color Doppler USG in type 2 diabetic patients having diabetic nephropathy and in healthy adult control subjects. Materials and methods: This cross sectional observational study was conducted in the Department of Radiology and Imaging, Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh. 65 diabetic nephropathy patients were taken as study group and 65 healthy subjects were included as healthy control subjects. Duplex Color Doppler Ultrasonography of interlobar artery was carried out in both groups to measure the peak systolic velocity, the end diastolic velocity and arterial Resistive Index. Results: The Resistive Index of interlobar artery of left kidney in control group was 0.58±0.08 and the mean RI of interlobar artery of left kidney in diabetic nephropathy patients was 0.74±0.53. The difference of Resistive index of interlobar artery of left kidney in the two groups were statistically significant and the RI of right kidney of control & that of case groups were 0.60±0.09 and 0.76±0.03 respectively. In between control and case groups the RI of right kidney were statistically significant. So, resistive index of interlobar artery was increased in type 2 diabetic nrphropathy patients compared to control group. Conclusion: It can be concluded in present study that resistive index remains significantly higher in patients with diabetic nephropathy than in controls. Thus Duplex Doppler ultrasonography allows the rapid, noninvasive evaluation of the intrarenal vasculature and can be used as an easily available parameter of the evolution and a predictor in patients with clinical diabetic nephropathy. Keywords: Doppler Ultrasonography, Intrarenal Resistive Index, Diabetic Nephropathy