SPINAL CORD Dr. Sajjad Hussain Faculty in Neuroradiology Department of Radiology and Medical Imaging King Saud University / King Khalid University Hospital

Imaging Methods to Evaluate Spine Plain X-Ray Films - bones Myelogram – injection of contrast medium in CSF followed by x-ray images. Rarely performed now-a-days Computed Tomography (CT Scan) Magnetic Resonance Imaging (MRI) Spinal angiography – to evaluate arteries and veins Ultrasound – more in children Radionuclide Bone Scan – intravenous injection of radioactive material bound to phosphonates which deposit in bones, followed by images by gamma camera. DEXA – radionuclide scan for bone density (osteoporosis)

X-RAYS (RADIOGRAPHS) Often the first diagnostic imaging test, quick and cheap Small dose of radiation to visualize the bony parts of the spine Can detect Spinal alignment and curvature Spinal instability – with flexion and extension views Congenital (birth) defects of spinal column Fractures caused by trauma Moderate osteoporosis (loss of calcium from the bone) Infections Tumors May be taken in different positions (ie; bending forward and backward) to assess for instability

COMPUTERIZED TOMOGRAPHY (CT SCAN) Uses radiation Obtain 2-D images  can be processed to 3-D images Patients lies on a table that moves through a scanner Much detailed information regarding bony structures Limited information about spinal cord & soft tissues Entire spine can be imaged within a few minutes

CT SCAN

Magnetic Resonance Imaging (MRI) Gold standard of imaging for spinal cord disorders No radiation Can identify abnormalities of bone, soft tissues and spinal cord Patient lies still on a table that moves through a tunnel like structure Takes about 15 - 25 minutes Claustrophobic patients, uncooperative / semiconscious patients, and children may need sedation or general anesthesia Contraindications include implanted devices e.g. cardiac pacemakers, electromagnetic devices, certain metal clips and stimulators Artificial joints and other fixed metals  no problem

MRI SCANNER

MR images are multi-planar

MR images are very high resolution

MR images are very high resolution

Abnormalities of spinal cord Congenital Trauma Demyelination Tumors Ischemia

Congenital

MR#1868533 Lipomyelomeningocele with tethered cord, mistaken for myelomenigocele at birth and partially resected without untethering cord. Now 11 y/o with progressive cavovarus deformity, LE weakness and incontinence.

Antenatal US Antenatal MRI

Trauma

24 years old with paraplegia after road traffic accident since 3 years

Hyperflexion fx with ligamentous disruption and cord contusion

Vertebral Artery Dissection/Occlusion Secondary to C6 Fracture

Tumors

AJNR

Astrocytoma

Astrocytoma

Ependymoma Figure 3a.  Ependymoma in a 32-year-old woman with upper- and lower-extremity weakness and numbness and bowel and bladder dysfunction. (a) Contrast-enhanced sagittal T1-weighted MR image demonstrates a heterogeneously enhancing mass expanding the cervical spinal cord. A cyst with faint peripheral enhancement (arrowhead) is seen at the superior pole of the mass. (b) Sagittal T2-weighted MR image reveals that the mass is predominantly isointense relative to the spinal cord, with scattered areas of high signal intensity. There is a curvilinear area of low signal intensity (arrowheads) at the C2-3 level, which is suggestive of hemorrhage. (c) Intraoperative photograph demonstrates the lobulated, irregular mass with areas of hemorrhage (arrows).

venous hypertension (e.g. AV fistula) Cord Edema As in the brain, may be secondary to ischemia (e.g. embolus to spinal artery) or venous hypertension (e.g. AV fistula) Dural AVF MR#1316826

Transverse Myelitis Inflamed cord of uncertain cause Viral infections Immune reactions Idiopathic Myelopathy progressing over hours to weeks DDX: MS, glioma, infarction

Multiple Sclerosis Inflammatory demyelination eventually leading to gliosis and axonal loss T2-hyperintense lesion(s) in cord parenchyma Typically no cord expansion (vs. tumor); chronic lesion may show atrophy

Key Points for MS, Transverse myelitis, and ADEM MS lesions in spinal cord are more likely multiple, focal and peripherally located don’t cover the entire section on axial images often < 2 vertebral body heights on sagittal images are disseminated in time and space may enhance in acute phase Transverse myelitis lesions extend over >3 vertebral body heights on axial images often > 4 vertebral body heights on sagittal images no brain lesions ADEM and NMO lesions in spinal cord – similar but presence of Brain lesions  ADEM Optic nerve lesions  NMO

SYRINGOHYDROMYELIA Seen with: congenital lesions Chiari I & II tethered cord acquired lesions trauma tumors arachnoiditis idiopathic

SYRINX On imaging, a syrinx is a longitudinally oriented CSF-filled cavity with surrounding myelomalacia / gliosis may have a beaded or cystic expansile configuration