Spine Flashcards
Describe modic type end plate changes?
Type 1 - Oedem - T1 dark, T2 bright
Type 2 - Fat - T1 bright, T2 bright
Type 3 - Scar - T1 dark, T2 dark
Difference between residual disc and scar ?
Both T1 low
post contrast scar will enhance
What is Jefferson fracture
Burst fracture of C1
Axial loading - jumped into a pool
What is hangmans fracture?
Bilateral pedicles or pars fracture of C2
Anterior subluxation of the C2 body, canal widening so cord damage uncommon
associated avulsion fracture of the Anterio inferior corner of C2 (ALL)
What is teardrop fracture?
Anterior inferior corner
Flexion type (more common)
Strongly associated with anterior cord syndrome = Immediate paralysis
hyperextension injury, stable.
Rarely Posterior cord syndrome = Proprioception gone
DDX limbus
Clay-shovelers fracture?
Avulsion of the spinous process at C7 or T1
Chance fracture?
Horizontal fracture through the thoracolumbar spine (Seatbelt)
Types of odontoid fracture?
Type 1 - upper part (rare but usually stable)
Type 2 - base (unstable and most common)
Type 3 - through the dens and into the body of C2(unstable, but best prognosis for healing)
which type of os odontoideum fuses to the clivus?
Dystopic
Orthotopic is os right on top of the dens
Parone to subluxation and instabilty.
Associated with Morquios syndrome
Key differences between malignant vs benign compression fractures?
Malignant
-Convex posterior vertebral body cortex
-Involves posterior elements
-Epidural/paraspinal mass
-Multiple lesions
Benign
-Retropulsed fragments
- Transverse T1 and T2 dark band
What are open spinal dysraphism’s and the types?
Spina bifida Aperta
=Neural tissue is exposed through a defect in bone and skin.
Cord is going to be tethered
Myeloceles = neural placode is flush with skin
Myelomeningoceles = More common (98%) = neural placode protrudes above the skin.
What are closed spinal dysraphism with subcutaneous defects ?
Spina bifida occulta
= The defect is covered by skin
Meningocele = herniated CSF sac through defect in posterior elements. can be anterior sacrum
Lipomyelocele/lipomyelomenigocele = Lipomas with dural defect. Cord is tethered
Terminal myelocytsocele = herniation if terminal syrinx into a posterior meningocele.
What is cord regression ?
spectrum of partial or complete agenesis of the lumbosacral or coccyx
*Maternal diabetes
‘Blunted sharp’ high terminating cord is classic
‘shield sign’ - unopposed iliac bones
Associations with VACERTL and currarino triad
Elderly with progressive radiculomyelopathy. MRI - Abnormally enlarged, T2-hyperintense distal cord covered with dilated pial vein flow voids?
Type 1 Dural AVF
Most common type
Between the radiculomedullary arteries and veins
SAH and MRI shows intramedullary nidus. what type of spinal AVMs?
Type 2
INTRAMEDULLARY NIDUS. Present with SAH
From anterior or posterior spinal arteries
Associated with cutaneous angiomas - HHT and KTS
Which type of Spinal AVM can occur in child with Nidus with extramedullary and extraspinal extensions?
Type 3
Rare and terrible prognosis
intramedullary and extramedullary
Ventral fistula and intradural site of AVF?
Type 4 (Perimedullary Fistula)
Intradural extramedullary site of AVF.
Near the conus
Features of TB spine/Potts disease
Tends to Spares the disc spaces
Mutli-level thoracic skip involvement
‘Calcified psoas abscess’
Gibbus vertebrae with relatively intact intervertebral discs, large paraspinal abscesses
Mutliple short segment (<2cm) spinal lesions, affecting part of the cord. Predominantly in the cervical cord?
MS
Lesions can enhance when acute
Cord atrophy is large burden
Central cord lesion > 2 vertebral segments in length with eccentric enhancement in thoracic region.
Transverse myelitis
At least 2/3 of cross section of the cord affected (WM and GM).
‘Expansion of central cord’
Acute partial = lesions < 2 segments
Acute complete = lesions > 2 segments
** Acute partials are higher risk for developing MS**
DDx MS
- smaller usually confined to 1-2 vertebral levels
- affecting less than half of the cross-sectional area of the cord
DDx ADEM
-usually demyelination in WM of the brain
- if in spine, spares grey matter
Differences between MS and ADEM?
ADEM
-Favours the spinal dorsal WM
- Cranial nerve enhancement
- Basal ganglia and Pons lesions - unusual for MS
-anti-MOG igG +ve (50%)
Long segments (3 levels) lesions that involve the full transverse diameter of the cord?
NMO
Enhancement of the optic nerves
limited brain parenchymal involvement
Difficult to distinguish from ADEMs on first presentation
Bilateral symmetrically increased T2 signal in the dorsal columns without enhancement.
Subacute combined degeneration
Vit b12 def
‘inverted V sign’
Looks the same as
= AID patients = HIV Vacuolar myelopathy
T2 hyperintensity long segment that involves anterior horn cells and central cord.
Spinal cord infarct
‘Owl eye’ appearance (grey matter most vulnerable)
anterior spinal artery is commonest
Look for vertebral body infarcts 7
Will have diffusion restriction
Enhancement of the nerve roots of the cauda equina ?
GBS
Chronic > 8 weeks = Chronic inflammatory demyelinating polyneuropathy (CIDP)
Buzzoword - thickened diffused enhacing cauda nerve roots ‘ onion bulb’
Nerve roots are adherent peripherally given ‘empty thecal sac’ sign ?
Arachnoiditis
Common intramedullary lesion?
Astrocytoma
Ependymoma
Hemangioblastoma
Key differences between Astrocytoma and ependymoma?
Astrocytoma
- More common cervical cord
- Most common type in children
-Eccentric
-Longer segments
- Low T1, High T2 and enhance
- Oblong, fusiform expansion of cord
-40% have tumor cysts or syringohydromyelia
Ependymoma
- Cervical too and lower cord/conus etc
- Most common type in adults
- Central
- Shorted segment
- More often peripheral haemorrhage = Dark cap on T2
- Cysts
Intramedullary mass with serpentine vascular flow voids. Wide cord with prominent oedema?
Hemangioblastoma
1/3 VHL
syringohydromyelia is very common
may have the classic appearance of a cystic mass with an enhancing
mural nodule characteristic of cerebellar haemangioblastomas
intensely homogeneous enhancing tumour nodule
Common causes for Extramedullary intradural spinal tumours?
Schwannoma
Neurofibroma
Ganglioneuroma
Neuroblastoma
Meningioma
all can have a ‘dumbell’ apperance
solitary spial lesion with intradural and extradural components enlarging the neural foramen giving a ‘dumbell shape’. Do not envelop the adjacent nerves?
Schwannoma
Most common intradural and extramedullary tumour
Multiple think NF-2 or carney complex
Central necrosis or haemorrhaged favours
Two types of spinal neurofibromas?
Plexiform
- Long, bulky, multinodular nerve enlargement.
- Pathognomonic for NF-1
Solitary
-difficult to distinguish from schwannoma
-sporadic
TARGET SIGN = T2 bright rim, T2 dark centre
Lateral Menigocele
- also in NF-1 = DILATED neural foramen
Thoracic Intradural extramedullary mass that enhances homogeneously and avidly with contrast.
Mengionoma
Can have Ca”+ and dural tail
Interestingly no bony remodelling or hyperostosis
2nd most common intradural extramedullary tumour
10 year old boy with extradural mass which is expansile involving the posterior elements. T2 fluid-fluid levels?
ABC
Can look big and aggressive
15 year old boy with well circumscribed expansile lucent mass with sclerotic rim, in the posterior elements measure aporx 3cm. Extensive enhancement of the surrounding soft tissues?
Osteoblastoma
<1.5cm = Osteoid osteoma
-Often will see a nidus and surrounding sclerosis. Nidus is T2 bright
-Hx night pain better with aspirin
Lytic expansile lesion with no rim of sclerosis in the sacrum of an adult ?
GCT
Intramedullay, intradural and extradural spinal lesions
see picture
Parameters of Atlanto-occipital dislocation
Basion dens interval >12mm
Sot tissue swelling at >10 mm soft-tissue swelling anterior to C2
Odd ratio >1
