In a normal kidney, when should the maximum concentration of tracer occur after administering Tc-99m mertiatide?

The maximum concentration of tracer in a normal kidney after administering Tc-99m mertiatide typically occurs between 3 to 5 minutes post-injection. This timeframe aligns with the rapid uptake characteristics of the tracer which is used to assess renal function. Tc-99m mertiatide, a radiopharmaceutical, is specifically designed for renal imaging and is taken up by renal tubular cells, allowing for a quick visualization of kidney perfusion and function.

In this period, the tracer is efficiently secreted from the renal circulation into the renal tubules where it concentrates, reflecting the kidneys' ability to process the radiopharmaceutical. Monitoring within this critical timeframe is essential for accurate imaging and assessment, ensuring that clinicians obtain the most relevant data regarding kidney function.

Other timeframes, such as 1-2 minutes or 8-10 minutes, do not align with the expected kinetics of Tc-99m mertiatide, as the tracer will not have reached its peak concentration in the renal tissue at those earlier or later times. Peak concentration after 30-35 minutes would generally indicate a prolonged or abnormal response, which is not typical for a normal kidney. Thus, the choice of 3-5 minutes reflects the optimal timing for visualizing renal function