Acute focal bacterial nephritis: a systematic approach to diagnosis and treatment.

Acute focal bacterial nephritis, synonymous with acute lobar nephronia or focal nonliquefactive pyelonephritis, represents a localized area of renal inflammation. Clinically, acute focal bacterial nephritis presents as acute pyelonephritis but is distinguishable by the presence of a focal mass on excretory urography. The further distinction between acute focal bacterial nephritis and other renal masses is aided by the appropriate use of renal sonography and computerized tomography. The clinical and imaging manifestations in 9 patients with acute focal bacterial nephritis are described. Our experience coupled with a review of the literature suggests that a systematic approach to the diagnosis and management of acute focal bacterial nephritis allows for the most efficacious use of the noninvasive imaging modalities.