Tc-99m-DMSA circulates in blood bound to alpha-1-microglobulin. Because of its molecular size, the complex undergoes glomerular filtration at a slower rate than Tc-99m-DTPA with a renal extraction efficiency of about 5%. Filtered complex is reabsorbed intact into the proximal tubule where the DMSA component forms stable disulphide bridges with cortical proteins. Static imaging is performed 3 h following injection and records the functional morphology of the kidney. Reduced tracer accumualtion is seen in a range of destructive renal pathologies, especially scarring from urinary tract infection. By comparing the uptake between the two kidneys, Tc-99m-DMSA gives the relative function - not absolute function - of the two kidneys (split function), which is especially important in surgical management.