Imaging of traumatic brain injury Flashcards
Types of brain injury
Closed
Open
Closed TBI
Dura intact
More common
Violent acceleration
Open TBI
Dura disrupted
Less common
Fracture or FB penetrating dura
Coup is an injury at the ………… side
Countercoup is an injury at the …………. side
Same | opposite
Types of brain lesions
Primary
Secondary
Primary brain lesion
Caused by trauma
Skull fracture
Extra axial hemorrhage
Intra axial lesions (DAI, Contusions IVH)
Secondary brain lesions
Arise from :
Brain’s response to trauma
Compression on the structures
(Brain, CN, BV, skull, dura)
Herniations, diffused edema, infarction
In TBI, which type of imaging do you use
Non-contrast axial scan
3mm slice thickness
Bone algorithm
Coronal and Sagittal reformation
CT imaging protocol
Maxillary hemosinus > Facial CT
Basilar skull fracture > CT angio and skull base reformation
Suspect C-spine fracture > C-spine CT
Layers of the skull
Outer table
Dipole
Inner table
Part of the skull without ………….. are more ………….
Diploe | weak
Part of the skull without diploe
Squamous temporal Squamous partial Foramen magnum Skull base Cribiform plates Orbital roofs
Types of skull fractures
Linear fracture (EDH, SDH)
Depressed fracture (Focal parenchymal lesions)
Skull base fracture
Open head injury (Laceration of dura)
…………… skull x-ray does not mean …………
Negative | No CT
Causes of diffuse axonal injury (DAI)
Traumatic acceleration/deceleration
Violent rotation
Cerebral contusions result from
Impact of gyri to the inner table of skull
Intraparenchymal hematoma result from
Parenchymal vessel rupture from blunt or penetrating forces
Intraventricular hemorrhage :
Uncommon
Result from severe trauma
a/w DAI and trauma of deep grey and brainstem
Poor prognosis
Extra dural hemorrhage
Acute presentation Associated with skull fracture Unilateral Biconvex Does not cross sutures More in pts <40 years old
Subdural hematoma
Acute to subacute to chronic presentation All ages May be bilateral No association with fracture Usually due to trauma
Traumatic subarchnoid hemorrhage (TSAH)
Usually associated with other injuries
Common with contusions
Herniation is a ………… lesion
Secondary
Herniation types
Uncal Central Cingulate (subfalcine) Transcalvarial Upward Tonsillar
Most common type of brain herniations is
Subfalcine (cingulate)
Characters of posttraumatic traumatic cerebral edema
Generalized obliteration of cortical sulci and SA spaces
Thin ventricles
Diffused hypodensity
Loss of grey-white matter interface
Posttraumatic ischemia/infarct m/c cause
Herniation
m/c location of posttraumatic ischemia/infarct
Occipital (PCA)
2nd m/c location of posttraumatic ischemia/infarct
Frontal (ACA)
Rare location of posttraumatic ischemia/infarct
Basal ganglia
Posttraumatic secondary hemorrhage
Small hemorrhage
Classic in midline of pontomesencephalic junction
May be multiple
May extend to cerebellar peduncles
Acute hydrocephalus can occur secondary to
Brain herniation
IVH
Delayed hydrocephalus usually secondary to
Adherence of meninges to Cerebral convexity Basal cisterna Aqueduct Resulting in obstruction at level of ventricles and arachnoid granulations
Pros of MRI in TBI
Sensitive to small injuries
Better differentiation of hemorrhagic and non hemorrhagic lesion
