Perinephric abscess aspiration using ultrasound guidance.

A perinephric is difficult to diagnose by clinical examination and traditional radiographic imaging techniques. Five cases are described in which the sonograms revealed a sonolucent perinephric collection suggestive of perinephric abscess. Diagnostic percutaneous aspiration performed under ultrasound guidance is a rapid, reliable, and safe means of distinguishing an abscess from a noninflammatory collection.