Failure of sonography to visualize a kidney affected by emphysematous pyelonephritis

Abstract

We describe a diabetic patient who presented with acute renal failure as a result of acute bilateral emphysematous pyelonephritis. Initially, both an abdominal X-ray examination and a renal sonogram were unremarkable. Two days later, however, the previously visualized right kidney could not be demonstrated again by a repeat renal sonogram. A computed tomogram and a repeat abdominal X-ray study confirmed the diagnosis of emphysematous pyelonephritis. To our knowledge this is one of the few described cases of emphysematous pyelonephritis distinguished by a sonogram's inability to visualize a kidney because of interference with imaging by the gas produced by the bacteria that are responsible for the pyelonephritic infection.

Diabetes, Fever and Flank Pain: Is it Emphysematous Pyelonephritis?

“…[348] CT is the most reliable diagnostic tool with an accuracy of 100%. Based on CT scan findings, EPN is classified by Wan et al .…”

“…[ 2 ] X-ray and ultrasound abdomen are preliminary investigations but lack sensitivity and precision; hence, they cannot be always relied upon to visualize the kidney. [ 3 ] Computed tomography (CT) scan of the abdomen is the investigation of choice. [ 4 ] CT classifications are useful in the decision making regarding treatment and prognostication.…”

Emphysematous Pyelonephritis with Abscesses Masquerading as an Ordinary Urinary Tract Infection

“…Ultrasound is operator dependent and not sensitive when imaging gas (Rauf et al, 2007). Gas may appear as nonspecific echogenic foci and may be mistaken for nephrolithiasis.…”

Emphysematous Pyelonephritis

“…E. coli is the commonest organism (found in about 70% of patients). 1 EPN is a radiological diagnosis, as symptoms and signs are little or no different from other causes of urinary tract infection. 2 Diagnostic sensitivities of plain X-ray abdomen, IVP and USG of abdomen for diagnosis of EPN are 33-47%, 50% and 80-85% respectively.…”

“…2 Diagnostic sensitivities of plain X-ray abdomen, IVP and USG of abdomen for diagnosis of EPN are 33-47%, 50% and 80-85% respectively. [1][2][3] Presence of gas in urinary tract and renal parenchyma is often difficult to recognize on plain X-ray as it can be easily obscured by overlying bowel gas patterns. 2 Ultrasound examination is noninvasive and more readily available, however it is imprecise for the identification of gas in renal parenchyma 2 and the technique cannot always be relied upon to visualize a kidney as exemplified by the circumstances experienced by our patient.…”