[Usefulness of ultrasonography in the assessment of acute pyelonephritis]

The diagnosis of acute pyelonephritis (APN) is based fundamentally on the clinical and bacteriological findings. Radiology is useful in ruling out obstructive causes that often require surgical management. The present study analyzed the role of renal ultrasonography (US) in patients with clinical symptoms, signs and history compatible with APN that have normal plain abdominal x-rays.

87 patients who consulted our emergency services with symptoms and signs compatible with APN were reviewed. Patients who referred renal colic and those with a previous history of urological disease other than uncomplicated recurrent urinary tract infection were excluded. Patients with a plain abdominal x-ray compatible with lithiasis were excluded. Renal US evaluation was performed by the urologist to rule out hydronephrosis.

37 (42.5%) of the 87 patients had an abnormal US scan. These patients were evaluated again by US or IVP, or both (one case). Obstructive uropathy was demonstrated in only 5 cases (5.8%). These foregoing 5 patients were treated by surgery.

In our series, renal US evaluation indicated surgical treatment in 5.8% of patients with clinical features of APN and a plain abdominal x-ray with no evidence of lithiasis. This incidence is likely to be lower in the outpatient setting. It is difficult to propose a standard approach in the management of these patients. It may therefore be more reasonable to utilize US and IVP in those patients who do not respond to antibiotic therapy.