title: The role of unenhanced CT alone for the management of headache in an emergency department. A feasibility study.
abstract: OBJECTIVE
  To determine whether unenhanced CT alone could be sufficient for the screening of patients admitted with a suspicion of secondary headache in an emergency center.
  
  
  METHODS
  A feasibility study including consecutive patients admitted to our emergency department for acute non-traumatic headache, in whom a brain CT was required by the emergency physician, was conducted over a 3-month period of time. Patients with a suspicion of intracranial pathology, which can only be depicted by i.v. images (arterial dissection, venous thrombosis, or postoperative complication) were recorded but excluded from analysis. All patients underwent both unenhanced and i.v. enhanced cerebral CT, including CT angiography. Unenhanced CTs were reviewed by two radiologists, blinded to the clinical data, to the radiological reports and to the i.v. enhanced images. Unenhanced CT were sorted by the radiologists into three groups: (1) normal CT, (2) benign finding that could explain headache without need of injection of contrast media, (3) evidence of an intracranial pathology, requiring further imaging. Results were compared to i.v. enhanced CT images.
  
  
  RESULTS
  A brain CT was required in 105 patients (34 males, 71 females) during the study period, 74 (70%) of them met our inclusion criteria. Fifty-nine (80%) were sorted in group 1 (normal), four (5%) in group 2, 11 (15%) in group 3. No further finding that could explain acute headache was found on i.v. CT images in patients of group 1 or 2. A significant pathology was confirmed by i.v. CT in all patients of group 3.
  
  
  CONCLUSIONS
  This feasibility study suggests that a normal unenhanced CT might be sufficient to exclude the cause of headache in the initial screening of a selected group of patients admitted with cephalalgia. It compels researchers to perform further prospective studies to confirm the current data on a larger amount of patients.
authors.affiliation: Department of Radiology, CHU Poitiers, Poitiers, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Rizk
authors.forename: Alexandra
authors.initials: A
authors.lastname: Platon
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Tasu
authors.forename: Christoph D
authors.initials: CD
authors.lastname: Becker
authors.forename: Vitor
authors.initials: V
authors.lastname: Mendes Pereira
authors.forename: Thomas
authors.initials: T
authors.lastname: Perneger
authors.forename: Kathirkamanathan
authors.initials: K
authors.lastname: Shanmuganathan
authors.forename: Karl Olof
authors.initials: KO
authors.lastname: Lövblad
authors.forename: Pierre-Alexandre
authors.initials: PA
authors.lastname: Poletti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001927:Brain Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015984:Causality; D002533:Cerebral Angiography / Q000706:statistics & numerical data*; D015897:Comorbidity; D003287:Contrast Media; D003937:Diagnosis, Differential; D004632:Emergency Medical Services / Q000379:methods / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005240:Feasibility Studies; D005602:France / Q000453:epidemiology; D006261:Headache / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D006801:Humans; D007089:Image Enhancement; D008875:Middle Aged; D015995:Prevalence; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: Cephalalgia; Cerebral computed tomography angiography; Computed tomography scan; Contrast-enhanced computed tomography; Emergency department; Headache; Neuroimaging