Neuroradiology 2 Flashcards
Common causes of Central Canal Stenosis
Facet joint degenerative change (most common). Lligamentum flavum hypertrophy.
Most common cause of neuroforaminal stenosis
Facet joint degenerative change with bony encroachment.
Distinguishes postop scar from disk material
Scar tissue enhances. Disk material has only minimal peripheral enhancement.
Myelopathy neurologic signs
Ataxia. Bowel and bladder incontinence. Babinski sign.
Radiculopathy neurologic signs
Muscle weakness. Decreased reflexes. Dermatomal sensory deficits.
Intradural intramedullary lesions
Ependymoma. Astrocytoma. Hemangioblastoma. Lipoma/(Epi)dermoid. Syringohydromyelia. Intramedullary AVM.
Intradural extramedullary lesions (includes subarachnoid space)
Meningioma. Schwannoma/neurinoma. Neurofibroma. Hemangiopericytoma. Lipoma/(Epi)dermoid. Arachnoid cyst/adhesion. Drop/leptomeningeal metastasis. Veins (extramedullary AVM).
Extradural extramedullary lesions
Degenerative: Herniated disc. Synovial cyst. Osteophyte. Rheumatoid pannus. Nondegenerative: Metastasis. Abscess.
Urgency for imaging acute myelopathy
Poor prognosis if left untreated for greater than 24 hours.
Common causes of myelopathy
Extramedullary: Epidural mass cord compression. Cervical spine stenosis. Intramedullary: Tumor. Inflammation,
Atlantoaxial instability and rheumatoid arthritis
Inflammatory changes (pannus) destroy transverse ligament of C1. Dens may slide posteriorly and intermittently compress cord causing myelomalacia. 5% of RA patients frank atlantoaxial instability.
Vertebral body and disc infection findings
Adjacent vertebral bodies and disc usually involved. Destruction greatest at endplates. Posterior elements usually spared. Low T1 and high T2 marrow signal with normal diffusion. If pyogenic disk enhances, granulation tissue extends above and below affected vertebrae.
Vertebral body neoplasm findings
Isolated or noncontiguous involvement. Pedicles typically affected. Low T1 and high T2 signal with restricted diffusion. Disk typically spared (except prostate cancer). Enhancement may obscure metastases within fatty marrow.
Vertebral body osteoporosis findings
Several vertebral bodies with height loss. Anterior weding with posterior elements spared. Normal T1 and T2 unless fracture. Disk spared.
TB of the spine, or Pott disease
Causes slow collapse of one or more vertebral bodies. Gibbus deformity, acute kyphosis. Infection spreads underneath longitudinal ligaments. Can lead to cord compression. May spare disks.
Most common neoplasm of the spine
Metastases
Two most common primary intramedullary tumors
Astrocytoma. Ependymoma.
Spinal cord astrocytoma and ependymoma shared features
Expansile. Low T1 and high T2 signal with variable enhancement. Increased incidence in neurofibromatosis.
Spinal cord Ependymoma features
Most common spinal cord tumor in adults. Divided into cellular (intramedullary) and myxopapillary (filum terminale) types. Peak incidence inf ourth decade. Male predominance. These slow-growing neoplasms arise from ependymal cells lining the central canal of the cord or cell rests along the filum. Expansile. Low T1 and high T2 signal with variable enhancement. Increased incidence in neurofibromatosis.
Spinal cord Astrocytoma features
Most (75%) occur in cervical and upper to midthoracic cord. Fusiform cord widening. High T2 signal. Contrast enhancement over several vertebral body segments.
Hemangioblastoma features
Occur in spinal cord and posterior fossa. High association with Von Hippel-Lindau syndrome. Densely enhancing nidus with related cyst and or cord expansion. May be extramedullary and multiple. May be mistaken for arteriovenous malformation (AVM).
Syrinx
Shorter term for syringohydromyelia. Hydromyelia, dilation of central canal and lined by ependyma. Syringomyelia, cavity outside central canal lined by glial cells. Suspect tumor as a cause of unexplained syrinx.
Most common intradural tumor in thoracic region
Meningioma
Spinal meningioma features
Most (80%) occur in women. Average age of 45. Multiple meningiomas suspicious for neurofibromatosis. Usually extramedullary/intradural. Can have extradural component. Dense calcification can occur. Dense homogenous enhancement. Broad dural tails.
Most common intraspinal mass
Schwannoma
