Neuroradiology 1 Flashcards
What is a blooming artifact?
susceptibility artifact encountered on some MRI sequences in the presence of paramagnetic, the lesion appears larger than it actually is
What MR sequences maximize blooming artifact effects?
One of the most powerful and widely available sequences which maximizes blooming artifact to great effect is susceptibility-weighted imaging (SWI). Gradient echo and low B-value diffusion weighted imaging may also be useful in the absence of a dedicated susceptibility weighted sequence.
What types of compounds exhibit blooming artifact?
hemosiderin from prior hemorrhage, calcification, metal and gas
Describe von Hippel-Lindau Syndrome
Inherited disorder consisting of retinal angiomas and cerebellar and spinal hemangioblastomas. Cerebellar hemangioblastomas: well-circumscribed cystic lesions with enhancing mural nodule. Prone to sudden spontaneous hemorrhage. Other associations: renal cell carinoma, liver and kidney angiomas
Describe Sturge-Weber Syndrome
STURGE CAPS
S: seizures, sporadic
T: tram track gyriform calcification; trigeminal territory port-wine stain
U: unilateral weakness (hemiparesis - contralateral to facial nevus)
R: retardation
G: glaucoma, GNAQ gene
E: epilepsy
C: calvarial thickening, choroid plexus enlargement A: atrophy of ipsilateral cerebral hemisphere P: pial angiomatosis S: sinus (paranasal) enlargement
Describe tuberous sclerosis
HAMARTOMAS
H: hamartomas (CNS, retinal and skin) A: angiofibroma (facial) or adenoma sebaceum M: mitral regurgitation A: ash-leaf spots R: rhabdomyoma (cardiac) T: tubers (cortical, subcortical) O: autOsomal dominant (autosomal sounds like starting with letter "O" ) M: mental retardation A: angiomyolipoma (renal) S: seizures; Shagreen patche
What are neurofibromatosis type 1 findings?
CAFE SPOT
C: café-au-lait spots (greater than six seen during one year)
A: axillary or inguinal freckling
F: fibromas (neurofibroma (two or more) or plexiform neurofibroma (one)
E: eye hamartomas (Lisch nodules)
S: skeletal abnormalities, e.g. sphenoid wing dysplasia, leg bowing
P: positive family history
OT: optic tumor (optic nerve glioma)
What are neurofibromatosis type 2 findings (chromosome 22)?
Rule of 2s
neurofibromatosis type 2
chromosome 22 (22q12) gene location
bilateral vestibular schwannomas
presents in 2nd-4th decades (around 20 years)
initial prevalence estimated to be 1:200,000, now thought ~1:25,000
MISME
M: multiple
I: inherited
S: schwannomas
M: meningiomas and
E: ependymomas
Describe Dandy-Walker malformation
Large posterior fossa with high tentorial insertion. Dilated cysts 4th ventricle fills posterior fossa. Cerebellar vermis and hemispheres may be hypoplastic or absent.
Describe Chiari I malformations
Cerebellar tonsillar ectopia (tonsils extend > 5 mm below foramen magnum). Patients may be asymptomatic. May give rise to cervical spinal cord syrinx.
Describe Chiari II malformations
Chiari II malformations are relatively common congenital malformation of the spine and posterior fossa characterized by myelomeningocele (lumbosacral spina bifida aperta) and a small posterior fossa with descent of the brainstem and cerebellar tonsils and vermis. Numerous associated abnormalities are also frequently encountered.
In adults, at what level does the tip of the conus medullaris typically terminate?
The spinal cord is rostrally continuous with In adults, the tip of the conus typically terminates at the level of L1-L2, however it may terminate as high as mid-T12 or as low as L2-L3.
Where are the two enlargements of the cord?
The cord has two enlargements, cervical (C4-T1) and lumbosacral (T11-L1). The cervical enlargement provides innervation to the upper limbs via the brachial plexus, while the lumbosacral enlargement innervates the lower limbs via the lumbosacral plexus.
What are the two most common primary intramedullary tumors?
Astrocytoma and Ependymoma
What is most common neoplasm of the spine?
Metastases
