title: Ultrasound findings in EHEC-associated hemolytic-uremic syndrome and their clinical relevance.
abstract: OBJECTIVE
  Hemolytic-uremic syndrome (HUS) and acute kidney injury (AKI) after infection with Shiga toxin-producing E. coli (EHEC) are clinically important complications. We present a retrospective analysis of abdominal ultrasound findings in patients with HUS caused by EHEC O104:H4 (n = 41).
  
  
  METHODS
  We assessed intrarenal resistance indices and quantitated kidney parenchymal density by the kidney/liver intensity ratio using computer-based image analysis. Findings in EHEC-HUS were compared to those in AKI due to other reasons (n = 60) and 19 healthy volunteers.
  
  
  RESULTS
  Kidneys in EHEC-HUS patients showed severe morphologic changes with striking parenchymal echogenicity. Renal resistance index was increased in HUS (0.80 ± 0.08) compared to patients with AKI due to glomerulopathy (0.69 ± 0.08, p < 0.001) or patients with other causes of AKI (0.74 ± 0.10, p < 0.01). Parenchymal density was increased in EHEC-HUS (1.39 ± 0.35) compared to AKI due to glomerulopathy (1.18 ± 0.20, p < 0.05), other causes of AKI (1.12 ± 0.21, p < 0.001) and healthy controls (0.86 ± 0.16, p < 0.001). Patients with atypical HUS showed increased parenchymal density (1.43 ± 0.37), similar to those with EHEC-HUS. EHEC-HUS patients who required dialysis treatment had higher parenchymal density (1.58 ± 0.08) compared to those without dialysis (1.14 ± 0.05, p = 0.0004). Extrarenal findings in EHEC-HUS included hepatomegaly (45%), splenomegaly (39%), ascites (84%) and pleural effusions (84%).
  
  
  CONCLUSIONS
  Patients with EHEC-HUS had a characteristic constellation of morphologic abnormalities on ultrasound examination, indicating that the effects of HUS are not limited to the kidney but include multiple organs, possibly mediated through systemic capillary leakage. Assessment of parenchymal echogenicity contributes to the differential diagnosis of AKI. Parameters reflecting renal perfusion correlated with severity of disease and thus may have prognostic value in future patient evaluation.
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany. reising.ansgar@mh-hannover.de.
authors.forename: Ansgar
authors.initials: A
authors.lastname: Reising
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.|Department of Nephrology, Helios Hospital Erfurt, Erfurt, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Hafer
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Hiss
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.|Medical Clinic V, Teaching Hospital Braunschweig, Braunschweig, Germany.
authors.forename: Jan T
authors.initials: JT
authors.lastname: Kielstein
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Menne
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Faikah
authors.initials: F
authors.lastname: Gueler
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Beneke
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Silvia
authors.initials: S
authors.lastname: Linnenweber-Held
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Haller
authors.affiliation: Department of Nephrology and Hypertension, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
authors.forename: Gunilla
authors.initials: G
authors.lastname: Einecke
mesh_terms: D000328:Adult; D054324:Enterohemorrhagic Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000150:complications / Q000175:diagnosis* / Q000382:microbiology; D005260:Female; D006463:Hemolytic-Uremic Syndrome / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012189:Retrospective Studies; D018608:Ultrasonography, Doppler / Q000379:methods*
keywords: Acute kidney injury; EHEC; Hemolytic-uremic syndrome; Image analysis; Resistance index; Ultrasound