Intra and interobserver variability of renal allograft ultrasound volume and resistite index meausurements

Purpose. Aim of the present study was to evaluate the repeatability and reproducibility of the Doppler Resistive Index (R.I.) and the Ultrasound renal volume measurement in renal transplants. Materials and methods.Twenty-six consecutive patients (18 men, 8 women) mean age of 42,8±12,4 years (M±SD) (range 22-65 years) were studied twice by each of two trained sonographers using a color Doppler ultrasound scanner. Twelve of them had a normal allograft function (defined as stable serum creatinine levels <=123,76 ?mol/L), whilst the remaining 14 had decreased allograft function (serum creatinine 132.6-265.2 ?mol/L). Results were given as mean of 6 measurements performed at upper, middle and lower pole of the kidney. Intra- and interobserver variability was assessed by the repeatability coefficient and coefficient of variation (CV). Results. Regarding Resistive Index measurement, repeatability coefficient was between 0.04 and 0.06 and the coefficient of variation was <5%. The analysis of the Student's t test did not show any significant difference between the measurements (t=0.15; p=0.87 n.s.). A good reproducibility was also detected in US measurements of renal length and volume. Conclusions. These results suggest that Color Doppler Resistive Index measurements of renal allograft and Ultrasound renal volume measurements are repeatable and reproducible.