13. Radiology of trauma Flashcards
When is skull radiography useful (SXR)
calvarial fractures
penetrating injuries
radiopaque foreign bodies
what is CT sensitive to in brain
mass effect
ventricular size
bone injuries
acute haemorrhage
what are limitations of CT
small and non-haemorrhagic lesions (contusion)
DAI
Detecting increased ICP or cerebral oedema
Early demonstration of HIE
ionising radiation
What is mri sensitive to
subacute and chronic brain injuries
what does mri show superior contrast resolution for
non-haemorrhagic primary lesions or secondary effects(oedema, HIE, DAI)
what mri imaging sequence is i
haemosiderin-sensitive T2W GRE
SWE
FLAIR for subarachnoid haemorrhage and lesions bordered by CSF
what is MRI limited by
not available in acute trauma setting long imaging times- patient motion insensitive to subarachnoid haemorrhage medical devices incompatability risk of in-dwelling devices
types of vascular injuries
penetrating trauma
basal skull fracture
trauma to the next
best way to show dissection
angiography
when to investigate for -
- glasgow coma scale(gcs)
- vomiting&headache
- amnesia
- drug intox
- age
- anticoagulation
- <13 <15
- not predictive in children
- longer - more chance haemorrhage
- up to 8% alchohol intoxicated
- > 60 and infants
- not clear
types of primary neuronal injury
cortical contusions
diffuse axonal injury
primary brain stem injury
types of primary haemorrhage
subarachnoid haemorrhage
subdural haematomas
extra dural haematomas
intracerebral haematomas
how can cortical contusion happen
consequence of direct trauma usually against skull,
skull impacts on brain forms ‘brain bruise’
how can DAI happen
e.g. hit by car on side
momentum of brain tissue
gm and wm move in different way causes vascular injury and shearing force
diffuse happens throughout the brain in diff. densities of tissue
with ct can’t distingshh dai early on
mri can pick hameorrghes deep in
how can subarachnoid haemorrhage happen
in case of intercranial arterial rupture e.g. aneurysm or trauma
marked arterial blood within system
how can subdural haemorrhage happen
any form of injury causes mass effect, subdural can accumulate and there can be multiple sites
how can parenchymal haemorrhage happen
more frontal impact. vessels that supply brain focus deep in more discrete
what do vascular injuries take form in
dissections, lacerations, occlusions, pseduoaneurysms, arteriovenous fistulas
how do vascular injuries occur
basal skull fractures
what imaging to use for vascular injuries
CTA MRA DSA
why do surgery for fractures
- depressed skull is more than full thickness of the skull
- open fractures that give rise to pneumocephalus
- relieve or prevent CSF leakage, infection, hameorrhage, or vascular compromise
imaging for fractures
SXR, CT
CT, contrast CT or radionuclide cisternography used for detecting sites of CSF leaks
what damage do foreign bodies cause
direct laceration
shock-wave transmission
cavitation
types of secondary injury
territorial arterial infarction (prolonged transtentorial and subfalcine herniations, direct vascular laceration, thrombosis and embolism)
- global anoxia and ishemia
- pressure necrosis
- brain herniation syndromes
- delayed haemorrhages
- secondary brain stem injuries
pathologic features of head injury
parenchymal atrophy residual haemoglobin degradation products wallerian-type axonal degeneration demyelination cavitation microglial scarring
injury guidance for spine
-anterior 2/3 vertebral body, disc and ant. long. ligament (ALL)
- posterior 1/3 vertebral body, disc and PLL
-pedicles, transverse processes, laminae, articular facets and spinous processes
- 2 columns = unstable injury
NG41 guidelines(canadian c-spinerule)
what imaging to do in spine for children and adults?
children - MRI or x-ray (if no neurology)
adults - CT if canadian rule, neurology, T/L injury
otherwise x-ray
otherwise MRI
what are the mechanisms of cervical injury
hyperflexion
hyperextension
axial compression
upper cervical spine features
complex flexion/extension atlanto-occipital dislocation odontoid peg fractures extension (hangman's fracture) vertical compression (Jefferson's fracture)
types of fractures in lower cervical spine
flexion –> flexion teardrop fracture, wedge compression fracture, clay shoveler’s fracture, bilateral facet joint dislocation
flexion-rotation –> (unilateral facet joint dislocation)
vertical compression –> burst fracture
what are soft tissue spinal injuries
anterior subluxation ligamentous injuries cord contusion brachial plexus vertebral arteries
what are thoracolumbar spine fractures
due to weight bearing type forces, disrupt alignment
- wedge compression fractures
- burst fractures
- chance fractures
- spondylolisthesis
- spondylolysis
