Spinal Imaging脊髓成像.doc

Spinal Imaging21/5/11Diagnostic Imaging in Critical Care- CT is the best way to image the spine for bony injuries (will miss 6% of discoligamentous injuries)- if suspected soft tissue or spinal cord injury - patient requires an MRICHECK LISTSagittal images- space between anterior arch of C1 and peg ( 3mm in adults, 5mm in children)- posterior cortex of C1- anterior cortex of peg- spinolaminar line of C1-C3- anterior and posterior spinolaminar lines- bodies height and alignment- facets aligned- no subluxation or widening- no prevertebral swelling- discs intact- no soft tissue swellingAxial images- space between arch and peg 3mm- no significant rotation ( 50%, angulation- surgical emergency: requires urgent traction or immediate open reduction if patient is neurological normal or has a incomplete spinal injury.Unilateral facet joint dislocation- AP: spinous processes below the dislocation do not align with those above it, interspinous processes widened.- lateral: facet joint dislocation, 25% forward shift- oblique: facet join dislocation better seen- traction can be used but if unsuccessful - emergency surgery seldom required.Odontoid fractures- I: tip of odontoid- II: junction of dens and body- III: extending into body of C2Atlanto-occipital subluxation- can be potentially fatal - injury of craniocervical junction or brain stem- I: anterior subluxation- II: vertical distraction of atlanto-occipital joint 2mm- III: posterior dislocationCompressive flexion injury- I: blunting of the anterior-superior vertebral margin- II: beak-like appearance to the anterior vertebral body with loss of anterior vertebral height and an oblique contour.- III: fracture extending from the anterior surface of the vertebral body into the disc space.- IV: posterior displacement of the inferoposterior aspect of the vertebral body 3mmDistraction extension injury- I: abnormal widening of the disc space (disruption of the anterior longitudinal ligament and disc)- II: posterior ligaments are disrupted and the cephalad vertebrae are displaced into the spinal canal.Compressive extension injury- damage to vertebral arch but the body of the affected vertebra remains intact.- can be unilateral or bilateral- can involve the pedicle, articular or lamina (or a combination of these)Vertebral compression injury- body fracture (loss of height)- retropulsion into the vertebral canal- I: central fracture of either the superior of inferior endplate with a cupping deformity- II: both endplates are involved- III: vertebral body fragmented with fragments displaced in multiple directions.Diffuse idiopathic skeletal hyperostosis (DISH)- anterior extensive ossification along vertebral bodies.- if come with neck pain - require an MRI as cord is very susceptible given small canal.Chance fracture- flexion-distraction injury- widening of the interspinous interval- fracture line through the body- high incidence of a intra-abdominal injuryTRICKS AND TRAPSCongenital anomalies- look for fractures lines - if lines smooth think congenital problem- deficiency in pos