The Renal function is best assessed by:

Ans. C. Tc 99m MAG3* The Renal function is best assessed by Tc-99m MAG3 (mercaptoacetyltriglycine). It is eliminated through kidney as via both glomeruli filtration and tubular excretion.* Tc-99m DMSA (dimercaptosuccinic acid) is used to evaluate renal structure and morphology, particularly in pediatric imaging for detection of scarring and pyelonephritis.* DMSA is an ideal agent for the assessment of renal cortex as it binds to the sulfhydryl groups in proximal tubules at the renal cortex with longer retention than other agents. Also, it allows better assessment of differential renal function* Tc-99m DTPA (diethylene-triamine-Penta acetate) is cleared only via glomeruli with no tubular excretion. Hence used for direct measurement of GFR.* The screening investigation used in reno-vascular hypertension is Captopril DTPA and the gold standard investigation is renal angiography.