title: Utility of emergency cranial computed tomography in patients without trauma.
abstract: OBJECTIVE
  The objectives of this study were to determine, in patients admitted to the hospital from the emergency department (ED) without evidence of trauma, 1) the prevalence of clinically important abnormalities on cranial computed tomography (CCT) and 2) the frequency of emergent therapeutic interventions required because of these abnormalities.
  
  
  METHODS
  The authors retrospectively reviewed the records of all patients from 2007 between the ages of 18 and 89 years who had CCT as part of their ED evaluations prior to hospitalization. Patients with any indication of trauma were excluded, as were those who had a lumbar puncture (LP). Chief complaint, results of the ED neurologic examination, tomogram findings, and whether patients had emergent interventions were recorded. Patients presenting with altered mental status (AMS) were analyzed separately.
  
  
  RESULTS
  Of the 766 patients meeting inclusion criteria, 83 (11%) had focal neurologic findings, and 61 (8%) had clinically important abnormalities on computed tomography. Emergent interventions occurred in only 12 (1.6%), 11 (92%) of whom had focal neurologic findings. In the subgroup of 287 patients with AMS as their presenting problem, 14 (4.9%) had focal findings, six (2%) had clinically important abnormalities on tomography, and only two (0.7%) required emergent interventions, both of whom had focal findings. Patients presenting with AMS were less likely to have positive findings on tomography (odds ratio [OR] = 0.16, 95% confidence interval [CI] = 0.07 to 0.39). Patients presenting with motor weakness or speech abnormalities, or who were unresponsive, were more likely to have positive findings on tomography (OR = 4.7, 95% CI = 2.6 to 8.6; OR = 4.4, 95% CI = 1.5 to 2.7; and OR = 3.3, 95% CI = 1.6 to 7.1, respectively).
  
  
  CONCLUSIONS
  Of patients without evidence of trauma who receive CCT in the ED, the prevalence of focal neurologic findings and clinically important abnormalities on tomography is low, the need for emergent intervention is very low, and the large majority of patients requiring emergent intervention have focal findings. The yield of CCT was lower for patients presenting with AMS, and higher for patients presenting with motor weakness or speech abnormalities, and for those who were unresponsive.
authors.affiliation: Department of Medicine, Denver Health, and University of Colorado School of Medicine, Denver, CO, USA. vignesh.narayanan@dhha.org
authors.forename: Vignesh
authors.initials: V
authors.lastname: Narayanan
authors.forename: Angela
authors.initials: A
authors.lastname: Keniston
authors.forename: Richard K
authors.initials: RK
authors.lastname: Albert
mesh_terms: D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D016001:Confidence Intervals; D004635:Emergency Medicine / Q000379:methods; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D009485:Neuroradiography / Q000706:statistics & numerical data; D016017:Odds Ratio; D015995:Prevalence; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D019564:Unnecessary Procedures / Q000706:statistics & numerical data*; D014947:Wounds and Injuries / Q000000981:diagnostic imaging / Q000628:therapy; D055815:Young Adult