What type of renal scan is used to evaluate for cortical scarring related to pyelonephritis or vesicoureteral reflux? How does it work?
Pyelonephritis can result in renal scarring, hypertension, proteinuria, and renal failure. Renal scarring from vesicoureteral reflux accounts for 10% to 20% of patients with end-stage renal disease. A renal scan with 99m Tc dimercaptosuccinic acid (DMSA) is more sensitive than US or intravenous urography (IVU) for the detection of parenchymal involvement. This radiotracer binds to the renal cortex and is essentially not excreted into the urine, allowing for imaging of the renal cortex to evaluate for areas of abnormally decreased radiotracer uptake. Imaging typically is performed approximately 20 minutes after injection, and single photon emission computed tomography (SPECT) is used to provide tomographic images for evaluation.