Reviewed Radiopharmaceuticals Tc99m DTPA or Tc99m MAG3. Both agents assess renal function. MAG3 primarily taken up and secreted by tubular cells of kidney. Captopril Captopril given orally at the time of administration of these agents to identify hemodynamically significant renal artery stenosis.
Mechanism relates to dilitation of efferent glomerular arterioles.
More importantly, captopril renal imaging appears to predict response to intervention.