====== Traumatic brain injury diagnosis ====== The goals of [[traumatic brain injury]] imaging include: (1) detecting injuries that may require immediate surgical or procedural intervention (2) detecting injuries that may benefit from early medical therapy or vigilant neurologic supervision (3) determining the prognosis of patients to tailor rehabilitative therapy or help with family counseling and discharge planning ((Wintermark M, Sanelli PC, Anzai Y, Tsiouris AJ, Whitlow CT; ACR Head Injury Institute. Imaging Evidence and Recommendations for Traumatic Brain Injury: Conventional Neuroimaging Techniques. J Am Coll Radiol. 2014 Nov 25. pii: S1546-1440(14)00676-0. doi: 10.1016/j.jacr.2014.10.014. [Epub ahead of print] PubMed PMID: 25456317. )). Missed or delayed detection of progressive neuronal damage and secondary brain damage after intracranial injuries may have a negative impact on the outcome of patients with traumatic brain injury (TBI) ((Becker DP, Miller JD, Ward JD. The outcome from severe head injury with early diagnosis and intensive management. Journal of Neurosurgery. 1977;47(4):491–502.)). Although CT, MRI, and TCD were determined to be the most useful modalities in the clinical setting, no single imaging modality proved sufficient for all patients due to the heterogeneity of TBI. All imaging modalities demonstrated the potential to emerge as part of future clinical care ((Pacifico A, Amyot F, Arciniegas D, Brazaitis MP, Curley K, Diaz-Arrastia R, Gandjbakhche A, Herscovitch P, Hinds SR, Manley GT M D Ph D, Razumovsky A, Riley J, Salzer W, Shih R, Smirniotopoulos JG, Stocker D. A Review of the Effectiveness of Neuroimaging Modalities for the Detection of Traumatic Brain Injury. J Neurotrauma. 2015 Jul 15. [Epub ahead of print] PubMed PMID: 26176603. )). Despite the obvious advantages of MRI in terms of delineating the extent and severity of brain injury, the MRI suite is not immediately accessible, and CT remains the modality of choice in the acute phase. Due to its sensitivity to venous blood [[SWI]] is commonly used in [[traumatic brain injury]] (TBI) ===== Spine films ===== 1. [[cervical spine radiography]]: must be cleared radiographically from the cranio-cervical junction down through and including the C7-T1 junction. Spinal injury precautions (cervical collar...) are continued until the C-spine is cleared. 2. [[thoracic spine radiography]] and [[lumbosacral spine radiography]] should be obtained based on physical findings and on mechanism of injury. ===== Skull radiography ===== see [[Skull radiography for head trauma]]. ===== CT ===== see [[Head computed tomography for traumatic brain injury]]. ===== MRI ===== Usually not appropriate for acute head injuries. This is due to longer acquisition time, less access to patient during study, increased difficulty in supporting patient (requires special non-magnetic ventilators, cannot use most IV pumps...) and MRI is less sensitive than CT for detecting acute blood ((Snow RB, Zimmerman RD, Gandy SE, Deck MDF. Comparison of Magnetic Resonance Imaging and Computed Tomography in the Evaluation of Head Injury. Neurosurgery. 1986; 18:45–52)). There were no surgical lesions demonstrated on MRI that were not evident on CT in one study ((Wilberger JE, Deeb Z, Rothfus W. Magnetic Reso- nance Imaging After Closed Head Injury. Neurosur- gery. 1987; 20:571–576)). There may be some additional benefit in combining CT with an MRI performed directly in the emergency department ((Kesterson L, Benzel EC, Marchand EP, et al. Magnetic Resonance Imaging in Acute Cranial and Cervical Spine Trauma. Neurosurgery. 1990; 26)). MRI may be helpful later after the patient is stabilized, e.g. to evaluate brainstem injuries, small white matter changes, ((Levin HS, Amparo EG, Eisenberg HM, et al. Magnetic Resonance Imaging After Closed Head Injury in Children. Neurosurgery. 1989; 24:223–227)) e.g. punctate hemorrhages in the corpus callosum seen in di use axonal injury Spinal MRI is indicated in patients with spinal cord injuries. Rapid sequence MRI may be useful for follow-up in pediatrics to minimize radiation exposure. ---- CT imaging is limited by beam hardening effects, which can partially obscure the posterior fossa, temporal and frontal regions, and partial volume errors. The latter occur when a region of injured tissue has one or more dimensions that are smaller than the resolution of the acquired data ((Lee B, Newberg A. Neuroimaging in traumatic brain imaging. NeuroRx 2005;2:372-83.)). This can mean that haemorrhage or other evidence of intracranial pathology may remain undetected. Such issues are of particular concern within the brain stem and spinal cord, where a small area of pathology can result in devastating injury, and in many patients who exhibit evidence of diffuse axonal injury (DAI) after trauma. DAI is a frequent finding after TBI, accounting for up to 50% of trauma patients ((Hammoud DA, Wasserman BA. Diffuse axonal injuries: pathophysiology and imaging. Neuroimaging Clin N Am 2002;12:205-16.)). The regions of the brain that are commonly injured include the grey–white matter interface, corpus callosum and deep white matter, periventricular and hippocampal areas, and brainstem ((Hammoud DA, Wasserman BA. Diffuse axonal injuries: pathophysiology and imaging. Neuroimaging Clin N Am 2002;12:205-16.)). Such regions are best visualized using MRI ((Pierallini A, Pantano P, Fantozzi LM, et al. Correlation between MRI findings and long-term outcome in patients with severe brain trauma. Neuroradiology 2000;42:860-7.)). ==Gradient echo MRI== Gradient echo MRI is sensitive to changes in magnetic susceptibility which results in lesions of low intensity after haemorrhage within the brain due to local magnetic field inhomogeneities caused by the paramagnetic properties of haemosiderin. By employing a variety of different MR sequences, the extent of brain injury can be demonstrated with high resolution across the brain. Micro-hemorrhages are a common result of traumatic brain injury (TBI), which can be quantified with [[susceptibility weighted imaging]] and mapping ([[SWIM]]), a quantitative susceptibility mapping approach. ===== Arteriogram in trauma ===== Cerebral arteriogram: useful with non missile penetrating trauma. ===== References =====