Neuroradiology 3 Flashcards
Spinal schwannoma features
Neuroforaminal extension and expansion are common in cervical and thoracic spine with intra and extraspinal components, dumbbell shape. In lumbar spine, tend to remain within dural sac.
Common intrathecal drop metastases
Subarachnoid seeding of primary CNS tumors: Posterior fossa medulloblastomas. Ependymomas. Pineal region neoplasms.
Most common spine extradural neoplasm
Metastatses: Breast, Lung, Prostate carcinoma.
Very low T1 and T2 marrow signal
Myelofibrosis
Spinal AVM features
May be intramedullary or extramedullary. Intramedullary AVMs have a nidus of abnormal vessels that may cause hemorrhage or ischemia. Extramedullary AVMs generally are arteriovenous fistulas. Spinal dural arteriovenous fistulas (SDAVFs) cause symptoms through venous hypertension and congestion of the cord with edema.
Tethered Cord features
Low-lying conus medullaris. In a newborn conus normally at L2. Typically ascends one to two vertebral segments as child grows. May form a taut mass in posterior lumbar canal, obscuring conus/cauda junction.
Caudal Regression Syndrome
Hypoplastic or absent distal spine and sacrum. Blunted conus.
Spinal Arachnoid cysts and epidermoids
Similar to brain arachnoid cysts and epidermoids. Arachnoid cysts follow CSFsignal. Epidermoids restrict diffusion, bright on DWIs.
Spinal Epidural Hematoma
Ventral epidural space contains plexus of veins. These can tear in trauma, resulting in epidural hematoma.
Nerve Root Avulsion
Most commonly occur in cervical spine. Typically involve roots of brachial plexus and upper extremities. Birth trauma from shoulder traction is common example.
Acute versus chronic sinusitis findings
Acute sinusitis: Air-fluid levels and foamy secretions. Typically caused by viral URI. Chronic sinusitis: Mucoperiosteal thickening. Thickening of bony sinus walls.
Sphenoid sinusitis is of great clinical concern as it may
Extend intracranially due to presence of valveless veins.
Sinus mucous retention cyst versus mucocele
Mucous retention cyst: Obstructed mucous glands within mucosal lining. Usually round. 1 to several cm in diameter. Mucocele: Entire sinus is obstructed. Expansion of sinus. Sinus wall bony thinning and remodeling. Mass may be present obstrucing draining ostium.
Inverting Papilloma
Neoplastic epithelium inverts and grows into underlying mucosa of lateral nasal wall. Surgically resected due to association with squamous cell carcinoma.
Juvenile nasopharyngeal angiofibromas
Male adolescents with epistaxis. Benign tumor but can be locally aggressive. Fills nasopharynx and bows posterior wall of maxillary sinus forward. Retromaxillary pterygopalatine fossa location is a hallmark feature. Avidly enhance.
