EVALUATION OF OBSTRUCTED KIDNEYS BY DISCRIMINANT-ANALYSIS OF TC-99M-MAG(3) RENOGRAMS

This study sought to develop a method of improving the differential di agnostic between healthy and obstructed kidneys using only parameters derived from the (TC)-T-99m-MAG(3) renogram. The analysis included dat a from 46 healthy and 36 obstructed kidney units. The parameters calcu lated were: mean transit time (MTT), time at 20% of the initial height of the renal retention function (T20) and time to peak of the renogra m (TP). A discriminant analysis was carried out to obtain a discrimina nt function in order to differentiate between the two groups. The best results were obtained using the function: (2.5629 lnT20) +(2.1280 ln TP) -27.1224 which correctly classified 97.56% of the cases, giving a sensitivity of 94.44% and a specificity of 99.99%.