imaging of head trauma
Download
Skip this Video
Download Presentation
IMAGING OF HEAD TRAUMA

Loading in 2 Seconds...

play fullscreen
1 / 82

IMAGING OF HEAD TRAUMA - PowerPoint PPT Presentation


  • 328 Views
  • Uploaded on

IMAGING OF HEAD TRAUMA. Dr. Thanh Binh Nguyen University of Ottawa, Canada July 2009. OUTLINE. Clinical indications for imaging Imaging technique Extraaxial hemorrhage Intraaxial injury Brain herniations Skull fractures. INTRODUCTION.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'IMAGING OF HEAD TRAUMA' - sahkyo


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
imaging of head trauma

IMAGING OF HEAD TRAUMA

Dr. Thanh Binh Nguyen

University of Ottawa, Canada

July 2009

outline
OUTLINE
  • Clinical indications for imaging
  • Imaging technique
  • Extraaxial hemorrhage
  • Intraaxial injury
  • Brain herniations
  • Skull fractures
introduction
INTRODUCTION
  • Head trauma is the leading cause of death in people under the age of 30.
  • Males have 2-3 x frequency of brain injury than females
  • Due mainly to motor vehicle accidents and assaults
classification of tbi
Classification of TBI
  • Primary
    • Injury to scalp, skull fracture
    • Surface contusion/laceration
    • Intracranial hematoma
    • Diffuse axonal injury, diffuse vascular injury
  • Secondary
    • Hypoxia-ischemia, swelling/edema, raised intracranial pressure
    • Meningitis/abscess
imaging technique
IMAGING TECHNIQUE
  • The presence of a skull fracture increases the risk of having a posttraumatic intracranial lesion.
  • However, the absence of a skull fracture does not exclude a brain injury, which is particularly true in pediatric patients due to the capacity of the skull to bend.
  • NO ROLE FOR PLAIN FILMS IN ACUTE HEAD TRAUMA
imaging technique7
IMAGING TECHNIQUE
  • CT without contrast is the modality of choice in acute trauma (fast, available, sensitive to acute subarachnoid hemorrhage and skull fractures)
  • MRI is useful in non-acute head trauma (higher sensitivity than CT for cortical contusions, diffuse axonal injury, posterior fossa abnormalities)
our ct protocols
OUR CT PROTOCOLS
  • “ROUTINE”: posterior fossa and supratentorial region (slice thickness = 5mm)
  • “TRAUMA”: posterior fossa (2.5mm), supratentorial region (5mm)
  • “TEMPORAL BONE”: <1mm in axial or coronal plane
  • “ORBITS/FACIAL BONES”: 1.25 mm axial/coronal orbits
approach to ct brain
APPROACH TO CT BRAIN
  • Look at the scout film: ? Fracture of upper cervical spine or skull
  • Look for brain asymmetry
  • Look at sulci, Sylvian fissure and cisterns to exclude subarachnoid hemorrhage
  • Change windows to look for subdural collection
  • Look at bone windows to see fractures
  • Determine if mass is intraaxial (in the brain) or extraaxial (outside)
scalp injury18
SCALP INJURY
  • Cephalohematoma: blood between the bone and periosteum. Cannot cross the suture lines.
  • Subgaleal hematoma: blood between the periosteum and aponeurosis. Can cross the suture lines.
  • Caput Succ: swelling across the midline with scalp moulding. Resolves spontaneously.
extraaxial fluid collections
Extraaxial fluid collections
  • Subarachnoid hemorrhage(SAH)
  • Subdural hematoma(SDH)
  • Epidural hematoma
  • Subdural hygroma
  • Intraventricular hemorrhage
subarachnoid hemorrage
Subarachnoid hemorrage
  • Can originate from direct vessel injury, contused cortex or intraventricular hemorrhage.
  • Look in the interpeduncular cistern and Sylvian fissure
  • Usually focal (but diffuse from aneurysm)
  • Can lead to communicating hydrocephalus
subdural hematoma
SUBDURAL HEMATOMA
  • Occurs between the dura and arachnoid
  • Can cross the sutures but not the dural reflections
  • Due to disruption of the bridging cortical veins
  • Hypodense(hyperacute, chronic), isodense(subacute), hyperdense(acute)
management of asdh
MANAGEMENT OF aSDH
  • Acute SDH with thickness > 10 mm or midline shift > 5mm should be evacuated
  • Patient in coma with a decrease in GCS by >2 points with a SDH should undergo surgical evacuation.
epidural hematoma
EPIDURAL HEMATOMA
  • Located between the skull and periosteum
  • Due to laceration of the middle meningeal artery or dural veins
  • Can cross dural reflections but is limited by suture lines
  • Lentiform shape (but concave shape in SDH)
management of aedh
MANAGEMENT OF aEDH
  • EDH > 30 cm3 should be evacuated.
  • EDH < 30 cm3 and <15 mm thickness and < 5 mm midline shift and GCS >8 may be managed nonoperatively with serial CT
intraventricular hemorrhage
Intraventricular hemorrhage
  • Most commonly due to rupture of subependymal vessels
  • Can occur from reflux of SAH or contiguous extension of an intracerebral hemorrhage
  • Look for blood-cerebrospinal fluid level in occipital horns
intra axial injury
INTRA-AXIAL INJURY
  • Surface contusion/laceration
  • Intraparenchymal hematoma
  • White matter shearing injury/diffuse axonal injury
  • Post-traumatic infarction
  • Brainstem injury
contusion lacerations
CONTUSION/LACERATIONS
  • Most common source of traumatic SAH
  • Contusion: must involve the superficial gray matter
  • Laceration: contusion + tear of pia-arachnoid
  • Affects the crests of gyri
  • Hemorrhage present ½ cases and occur at right angles to the cortical surface
  • Located near the irregular bony contours: poles of frontal lobes, temporal lobes, inferior cerebellar hemispheres
intraparenchymal hematoma
Intraparenchymal hematoma
  • Focal collections of blood that most commonly arise from shear-strain injury to intraparenchymal vessels.
  • Usually located in the frontotemporal white matter or basal ganglia
  • Hematoma within normal brain
  • DDx: DAI, hemorrhagic contusion
diffuse axonal injury
DIFFUSE AXONAL INJURY
  • Rarely detected on CT ( 20% of DAI lesions are hemorrhagic)
  • MRI: T1, T2, T2 GRE, SWI
slide46
DAI
  • Due to acceleration/deceleration to whtie matter + hypoxia
  • Patients have severe LOC at impact
  • Grade 1: axonal damage in WM only -67%
  • Grade 2: WM + corpus callosum (posterior > anterior) – 21%
  • Grade 3: WM + CC + brainstem
slide47
DAI
  • Hours:
    • hemorrhages and tissue tears
    • Axonal swellings
    • Axonal bulbs
  • Days/weeks: clusters of microglia and macrophages, astrocytosis
  • Months/years: Wallerian degeneration
brainstem injury
BRAINSTEM INJURY
  • By direct or indirect forces
  • Most commonly associated with DAI
  • Involves the dorsolateral midbrain and upper pons and is usually hemorrhagic
  • Duret hemorrhage is an example of indirect damage: tearing of the pontine perforators leading to hemorrhage in the setting transtentorial herniation
  • <20% of brainstem lesions are seen on CT
subfalcial herniation
SUBFALCIAL HERNIATION
  • Subfalcial: displacement of the cingulate gyrus under the free edge of the falx along with the pericallosal arteries.
  • Can lead to anterior cerebral artery infarction
uncal herniation
UNCAL HERNIATION
  • Displacement of the medial temporal lobe through the tentorial notch
  • Displacement of the midbrain
  • Effacement of the suprasellar cistern
  • Displacement of the contralateral cerebral peduncle against the tentorium
  • Widening of the ipsilateral cerebello pontine angle
  • Compression of the posterior cerebral artery
downward herniation
DOWNWARD HERNIATION
  • Caudal displacement of the thalamus and midbrain
  • Effacement of the perimensencephalic cistern and 4th ventricle.
  • Can cause a 3rd nerve palsy and disrupt pontine vessels leading to brainstem hemorrhage
upward herniation
UPWARD HERNIATION
  • Due to posterior fossa mass causing superior displacement of the vermis through the tentorial incisura
  • Compression of the 4th ventricle and effacement of the quadrigeminal plate cistern.
  • Compression of the superior cerebellar artery
tonsillar herniation
TONSILLAR HERNIATION
  • Inferior displacement of the cerebellar tonsils through the foramen magnum
  • Can lead to posterior cerebellar artery infarction
external herniation
EXTERNAL HERNIATION
  • Due to a defect in the skull in combination with elevated ICP
  • Venous obstruction can occur at the margins of the defect.
significant skull fractures
SIGNIFICANT SKULL FRACTURES
  • “Depressed”: inner table is depressed by the thickness of the skull.
  • Overlie major venous sinus, motor cortex, middle meningeal artery
  • Pass through sinuses
  • Look for sutural diastasis (lambdoid)
temporal bone fractures
TEMPORAL BONE FRACTURES
  • Look for opacification of the mastoid
  • Longitudinal: 70%, parallel to long axis of petrous bone, conductive hearing loss (from ossicular dislocation), facial nerve paralysis (20%)
  • Transverse: 20%, sensorineural hearing loss, facial nerve paralysis (50%)
  • Complex
  • Complications: meningitis, abscess
post traumatic sequelae
POST TRAUMATIC SEQUELAE
  • Carotid-cavernous fistula(CCF)
  • Dissection/pseudoaneurysm
  • Infarction
  • Atrophy/encephalomalacia
  • Infection
  • Leptomeningeal cyst
ad