title: Acute hemoperitoneum in children: prevalence of low-attenuation fluid.
abstract: BACKGROUND
  Recent evidence indicates that acute hemoperitoneum may have lower than expected attenuation values at CT.
  
  
  OBJECTIVE
  To characterize the attenuation of acute hemoperitoneum at CT in children following blunt abdominal trauma and to assess the prevalence of low-attenuation fluid.
  
  
  METHODS
  The CT scans of 19 consecutive children with isolated hepatic or splenic injury and associated peritoneal fluid were retrospectively analyzed. The attenuation value of peritoneal fluid was assessed in all peritoneal spaces.
  
  
  RESULTS
  Fluid was noted in 53 peritoneal spaces (27 abdominal, 26 pelvic). Fluid attenuation ranged from 20 to 64 HU. The mean fluid attenuation in pelvic spaces (37.5 +/- 9.4 HU) was significantly lower than in abdominal spaces (444.9 +/- 10.2 HU) (P = 0.008). Fluid in 8/26 (31 %) pelvic spaces and 2/27 (7 %) abdominal spaces had attenuation values < or = 30 HU. Fluid surrounding the site of injury (perihepatic or perisplenic space) was significantly higher in attenuation than fluid at other sites (P < 0.001). There was no correlation between the mean attenuation value of peritoneal fluid in each patient and the admission hematocrit (r = -0.14, P = 0.55).
  
  
  CONCLUSIONS
  There is great variability in the attenuation of acute hemoperitoneum. Blood in pelvic spaces has significantly lower attenuation than blood in abdominal spaces. Hemoperitoneum in the pelvis has values of < or = 30 HU in approximately one-third of spaces. The attenuation of acute hemoperitoneum does not correlate with hematocrit.
authors.affiliation: Department of Radiology, Rainbow Babies and Children's Hospital of the University Hospitals of Cleveland and Case Western Reserve School of Medicine, OH 44106-5056, USA.
authors.forename: K E
authors.initials: KE
authors.lastname: Basile
authors.forename: C J
authors.initials: CJ
authors.lastname: Sivit
authors.forename: M A
authors.initials: MA
authors.lastname: O'Riordan
authors.forename: E
authors.initials: E
authors.lastname: Marsh
authors.forename: E R
authors.initials: ER
authors.lastname: Grisoni
mesh_terms: D000007:Abdominal Injuries / Q000150:complications / Q000000981:diagnostic imaging*; D000208:Acute Disease; D000293:Adolescent; D001202:Ascitic Fluid / Q000000981:diagnostic imaging / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006465:Hemoperitoneum / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014949:Wounds, Nonpenetrating / Q000150:complications / Q000000981:diagnostic imaging*