Comparison of glomerular filtration rate by Gates method with Cockroft Gault equation in unilateral small kidney

ObjectiveTo compare the glomerular filtration rate (GFR) by 99mTc DTPA scan and the Cockroft Gault method in unilateral small kidney.Materials and methodsThe present study was conducted in the Department of Nuclear Medicine at the Sher-i-Kashmir Institute of Medical Sciences (SKIMS), India from July 2007 to April 2011. The present study included 47 patients with a diagnosis of unilateral small kidney on ultrasound. Out of 47 patients, 21 (44.7%) were males and 26 (55.3%) were females. Image processing was done using camera based methods. The GFR was automatically calculated by a software in a commercially available computer according to the Gates algorithm. The predicted creatinine clearance was calculated according to the Cockroft and Gault equation.ResultsMean total GFR by DTPA Gates method was 73.6 ± 18.6 ml/min and by the Cockroft Gault (CG) method was 79.8 ± 32.2 ml/min. The difference was statistically insignificant indicating an agreement between both the methods in measuring GFR.ConclusionsTo discuss the advantages of isotopic renography, CG cannot give individual kidney GFR and so is not of much use in the unilateral small kidney wherein the main aim is to know the function of the individual kidneys. Furthermore because of low cost and less radiation burden, this test might be preferred for routine practice in nuclear medicine.