title: The usefulness of brain magnetic resonance imaging with mild head injury and the negative findings of brain computed tomography.
abstract: OBJECTIVE
  To investigate the cases of intracranial abnormal brain MRI findings even in the negative brain CT scan after mild head injury.
  
  
  METHODS
  During a 2-year period (January 2009-December 2010), we prospectively evaluated both brain CT and brain MRI of 180 patients with mild head injury. Patients were classified into two groups according to presence or absence of abnormal brain MRI finding even in the negative brain CT scan after mild head injury. Two neurosurgeons and one neuroradiologist validated the images from both brain CT scan and brain MRI double blindly.
  
  
  RESULTS
  Intracranial injury with negative brain CT scan after mild head injury occurred in 18 patients (10.0%). Headache (51.7%) without neurologic signs was the most common symptom. Locations of intracranial lesions showing abnormal brain MRI were as follows; temporal base (n=8), frontal pole (n=5), falx cerebri (n=2), basal ganglia (n=1), tentorium (n=1), and sylvian fissure (n=1). Intracranial injury was common in patients with a loss of consciousness, symptom duration >2 weeks, or in cases of patients with linear skull fracture (p=0.00013), and also more frequent in multiple associated injury than simple one (35.7%>8.6%) (p=0.105).
  
  
  CONCLUSIONS
  Our investigation showed that patients with mild head injury even in the negative brain CT scan had a few cases of intracranial injury. These findings indicate that even though the brain CT does not show abnormal findings, they should be thoroughly watched in further study including brain MRI in cases of multiple injuries and when their complaints are sustained.
authors.affiliation: Department of Neurosurgery, Seoul Medical Center, Seoul, Korea.
authors.forename: Du Su
authors.initials: du S
authors.lastname: Kim
authors.forename: Min Ho
authors.initials: MH
authors.lastname: Kong
authors.forename: Se Youn
authors.initials: SY
authors.lastname: Jang
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Kang
authors.forename: Kwan Young
authors.initials: KY
authors.lastname: Song
keywords: Computed tomography; Magnetic resonance imaging; Mild head injury