title: The role of emergency ultrasound for evaluating acute pyelonephritis in the ED.
abstract: BACKGROUND
  Controversy remains over the imaging method of choice for evaluating acute pyelonephritis (APN) in the emergency department (ED).
  
  
  OBJECTIVE
  The aim of the study was to determine the efficacy of ultrasound in the diagnosis and management of patients presented to the ED with APN.
  
  
  METHODS
  This was a retrospective study of prospectively collected data. A cohort of ED patients diagnosed as APN were prospectively registered, and their medical records were then retrospectively reviewed for the presence of complications (admitted >14 days, admission to intensive care unit, or received invasive procedures), significant abnormalities (hydronephrosis, polycystic kidney diseases, renal abscess, emphysematous pyelonephritis), and mild abnormalities (cysts, stones, swelling).
  
  
  RESULTS
  The study included 243 patients. Most of the patients received one or more renal imaging studies (n = 206) and 39.5% of which were considered abnormal. The rates of significant abnormalities on different imaging methods were Kidney-ureter-bladder (KUB), 16.3%; emergency ultrasound (EUS), 39.6%; combination of KUB and EUS, 56.6%; and computed tomography, 58.8%. Factors contributed to complicated APN were elderly, male, a history of preexisting renal diseases, current use of catheters, previous renal calculi, and diabetes mellitus. Significant abnormalities can be identified by EUS in 61% of patients with complicated APN. In fact, the presence of significant sonographic abnormalities effectively diverted 34.3% of patients to receive surgical interventions (percutaneous nephrostomy, abscess aspiration, ureteroscopic stone manipulation, lithotripsy, or nephrectomy).
  
  
  CONCLUSIONS
  Structural abnormalities are not uncommon in ED patients with APN. Early assessment of these patients with EUS is likely to have a great impact on their diagnosis and management.
authors.affiliation: Emergency Department, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 11101, Taiwan.
authors.forename: Kuo-Chih
authors.initials: KC
authors.lastname: Chen
authors.forename: Shih-Wen
authors.initials: SW
authors.lastname: Hung
authors.forename: Vei-Ken
authors.initials: VK
authors.lastname: Seow
authors.forename: Chee-Fah
authors.initials: CF
authors.lastname: Chong
authors.forename: Tzong-Luen
authors.initials: TL
authors.lastname: Wang
authors.forename: Yu-Chuan
authors.initials: YC
authors.lastname: Li
authors.forename: Hang
authors.initials: H
authors.lastname: Chang
mesh_terms: D000208:Acute Disease; D000328:Adult; D016009:Chi-Square Distribution; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D007674:Kidney Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011704:Pyelonephritis / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000628:therapy; D012189:Retrospective Studies; D014463:Ultrasonography