Evaluation of the glomerular filtration rate by using the modified gates method (in vivo study) and the modification of diet in renal disease method (in vitro study) for patients with renal diseasesAuthor(s): Osiris W.Guirguis, Rania M.Abdel Halim, Adel M.K.Meselhy
The purpose of the study was to compare the estimation of glomerular filtration rate (GFR) from99mTc-DTPArenographywith that estimated from Modification of Diet in Renal Disease (MDRD) equation and studying the effect of different parameters on the evaluation of the glomerular filtration rate of patients with renal diseases such as radioactive 99mTc-DTPA for patients, time of counting of radioactive syringe and distance between syringe and detector of gamma camera. 99mTc-DTPArenography was performed on 158 patients with a wide range of renal function. The GFR was determined by twomethods: gamma camera uptakemethodmodified Gates (in vivo method); and Modification of Diet in Renal Disease method (MDRD) (in vitromethod).Different radioactivities of 3, 6, 9, 12, 15 and 18 mCi of 99mTc-DTPA are being counted within 60 seconds and at distance 30 cm from gamma camera detector. The radioactivity of 12 mCi is being counted in different times in the range from10 to 30 seconds and at different distances from 10 to 40 cm. The obtained results show that maximum count per pixelwas approximately the same in all images except for 3 mCi sample image, suggesting saturation of the pixels in high activities. In conclusion the Gates correlates withMDRD equation, and also, the 99mTc- DTPArenography will become more accurate in measurement of GFR, if the parameters are corrected.