Renal infarction versus pyelonephritis in a woman presenting with fever and flank pain.
Patients with fever, flank pain, and dysuria frequently are encountered in the emergency department. Acute pyelonephritis is the most likely diagnosis; however, its clinical and radiologic presentation consistently overlap with that of acute renal infarction. Ultrasound is unable to distinguish early infarction from nonabscessed acute pyelonephritis. Hence, computed tomography or magnetic resonance imaging are needed. We report the case of a 68-year-old woman who presented with fever, flank pain, and dysuria, along with respiratory distress and tachycardia. Elevated values for inflammatory indexes suggested a diagnosis of acute pyelonephritis, and subsequent contrast-enhanced computed tomography showed hypodense wedge-shaped areas in both kidneys. However, the presence of a thin rim of capsular enhancement (cortical rim sign), the absence of perirenal inflammatory changes, and the location of the lesions apart from defined calyces suggested the alternative diagnosis of renal infarction. The underlying cause was not identified until an episode of acute dyspnea revealed paroxysmal arrhythmia. Our case demonstrates that a thorough knowledge of the imaging findings of renal infarction and acute pyelonephritis is essential to correctly making the diagnosis.
SS Nefrologia, Department of Medical and Biological Sciences, ASOU san Luigi Gonzaga, University of Turin, Turin, Italy. Electronic address: gbpiccoli@yahoo.it.
Giorgina B
GB
Piccoli
SCDU Radiologia, Department of Oncology, ASOU san Luigi Gonzaga, University of Turin, Turin, Italy.
Adriano M
AM
Priola
SS Nefrologia, Department of Medical and Biological Sciences, ASOU san Luigi Gonzaga, University of Turin, Turin, Italy.
Federica N
FN
Vigotti
SS Nefrologia, Department of Medical and Biological Sciences, ASOU san Luigi Gonzaga, University of Turin, Turin, Italy.
Gabriella
G
Guzzo
SCDU Radiologia, Department of Oncology, ASOU san Luigi Gonzaga, University of Turin, Turin, Italy.
Andrea
A
Veltri
D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D005334:Fever / Q000175:diagnosis* / Q000209:etiology; D021501:Flank Pain / Q000175:diagnosis* / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D007238:Infarction / Q000150:complications / Q000175:diagnosis*; D007668:Kidney / Q000098:blood supply* / Q000473:pathology*; D011704:Pyelonephritis / Q000150:complications / Q000175:diagnosis*
Multifocal kidney infarction; acute pyelonephritis; acute renal infarction; cardiac-embolic disease, transient arrhythmia; computed tomography; renal atheroembolic disease; renal imaging; upper urinary tract infection