title: Utility of repeat head computed tomography after blunt head trauma: a systematic review.
abstract: BACKGROUND
  Repeat head computed tomography (CT) is standard practice for head-injured patients at many trauma centers. Utilization of CT has increased over time, yet effects on outcome and associated risks are unknown. We systematically reviewed the literature to determine the incidence of progression of injury on repeat CT and resulting treatment changes.
  
  
  METHODS
  Studies were included from Medline, Embase, and a hand search of citations in reviewed articles. Main outcome measures were progression of injury on repeat CT and resulting intervention. Data were abstracted from 30 eligible studies and discrepancies were settled by consensus.
  
  
  RESULTS
  Progression of injury on repeat CT was evident in 8 to 67% of patients in the included studies. Neurosurgical intervention resulting subsequent to a repeat CT occurred in 0 to 54% of patients. More severe traumatic brain injury, defined by Glasgow Coma Scale, was associated with a higher proportion of patients with progression of injury on CT and subsequent neurosurgical interventions. Risk factors associated with progression of injury on CT or resulting intervention were inconsistently reported, but coagulopathy and injury severity were most commonly reported. Few studies reported changes in nonsurgical management, in-hospital disposition, or adverse events associated with obtaining repeat CTs.
  
  
  CONCLUSIONS
  Indications for repeat head CT after traumatic brain injury are unclear. The wide range of reported injury progression on CT and resulting surgical and medical treatment changes suggest there may be a subset of patients who benefit from repeat CT. Further research should stratify by severity of traumatic brain injury, clearly define inclusion and exclusion criteria, address selection bias, quantify progression of injury on CT, determine factors predictive of injury progression and intervention, and assess risks associated with repeat CT.
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA. mcwang@u.washington.edu
authors.forename: Marjorie C
authors.initials: MC
authors.lastname: Wang
authors.forename: Ken F
authors.initials: KF
authors.lastname: Linnau
authors.forename: David L
authors.initials: DL
authors.lastname: Tirschwell
authors.forename: William
authors.initials: W
authors.lastname: Hollingworth
mesh_terms: D018450:Disease Progression; D019317:Evidence-Based Medicine; D016489:Head Injuries, Closed / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D019635:Neurosurgical Procedures / Q000706:statistics & numerical data; D018579:Patient Selection; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000009:adverse effects; D015599:Trauma Severity Indices