Radiologic evaluation of patients with renal infections.

Although renal imaging is not indicated routinely in cases of uncomplicated renal infection, CT is a highly sensitive modality to diagnose and guide the management of patients with acute renal infection. CT is particularly useful in identifying complications of renal infection. Intravenous urography and US are limited to screening for urinary obstruction, renal calculi, and underlying anomalies. CT is also of value in establishing the diagnosis in equivocal cases, in evaluating high-risk patients, and in determining the nature and extent of disease. CT urography is increasingly performed as a comprehensive urinary tract imaging study. MRI may be performed when patients have contraindications to iodinated contrast material. Cortical scintigraphy is the preferred imaging study for the evaluation of children with acute pyelonephritis, although power Doppler US can be considered as a possible alternative. Recent limited studies using gadolinium-enhanced MRI have been shown to be valuable in the depiction of changes of acute pyelonephritis.