In a child, non-functioning kidney is Best dignosed by

DTPA RENOGRAM : Inulin clearance remains the gold standard to measure GFR, but it is expensive, time consuming, an requires a steady-state plasma concentration and accurate and timed urine collection . 99&;Tc-DTPA is recommended agent is for GFR measurement. 5- 10% plasma protein binding, so it tends to underestimate the GFR(insignificant) Peak renal activity after 3 -- 4 min. 90 % filtered within 4 hours. The extraction fraction of 99Tc-DTPA is approximately 20 per cent; for this reason, not useful for imaging , in patients with impaired renal function. In such cases, agents with higher extraction efficiencies such as 99Tc-MAG3 more appropriate. Reference: GHAI Essential pediatrics, 8th edition