Imaging SBAs Unit 6 Flashcards
Child, Cerebellar mass, extending into cerebellopontine angle. Intense enhancement and diffusion restriction with surrounding oedema
Atypical teratoid/rhabdoid
Primary CNS Lymphoma vs Toxoplasmosis
CNS:
Usually single lesion,
Subependymal spread,
Solid enhancement pattern
Toxoplasmosis:
Multiple lesions
Usually basal ganglia
Ring enhancement
Most posterosuperior ethmoid air cell, separated from optic nerve and ICA by very thin bone
Onodi cell
Most anterior ethmoidal air cell
Agger Nasi cell
Enhancing mass at base of tongue in midline
Lingual thyroid
Definitive Ix for herpes encephalitis
Lumbar puncture
Carotid body tumour MRI
Iso T1, High T2, multiple flow voids
Causes of high T1 in basal ganlgia
Calcification,
Haemorrhage, Wilsons, Long term TPN,
Chronic liver disease,
NF1 hamartomas
MIR signs of malignant transformation of pleomorphic adenoma
Heterogenous signal,
Irregular margins,
Lymphadenopathy,
adjacent soft tissue or bone spread,
Facial perineural spread
Pleomorphic adenoma MRI
Low T1, High T2.
Causes of visual field defects
Temporal lobe = contralateral superior quadrantinopia
Visual cortex = contralateral homonymous hemianopia
Occipital lobe = homonomous hemianopia with macula sparing
Optic chiasm = bitemporal hemianopia
Optic nerve = ipsilateral anopsia
Renal impairment, hypertension, intracranial aneurysm
ADPKD
Acute carbon monoxide poisoning MRI
High T2 signal in basal ganglia and globus pallidus with diffusion restriction
Multiple rounded cystic intracranial lesions, surrounding oedema, immunosuppressed.
Toxoplasmosis
Von-Hippel-Lindau associations
Cerebellar haemangioblastoma,
Spinal cord haemangioblastoma,
Retinal Haemangioblastoma,
Pancreatic cysts,
Renal cysts,
RCC,
Causes of basal ganglia calcification
Toxic (CO, Pb, radiation, chemo),
Infection (Torch),
Metabolic (hypothyroid, hypoparathyroid, pseudohypooparathyroid, hyperparathyroid)
Laryngoceles are associated with
Laryngeal Cancer
Intermittent cyanosis on crying in neonate (Dx and Ix)
Bilateral choanal atresia,
CT nasal passage
Swelling and high signal in hippocampi and amygdala.
Poor memory, hyponatraemia, seizures
Limbic encephalitis, often paraneoplastic
Sturge Weber caused by
Cortical venous angioma with gradual calcification
Heterogenous cystic mass with solid enhancing components and calcification - Suprasellar
craniopharyngioma
NF1 diagnostic criteria
2 or more of the following:
6 cafe-au-lait spots during 1 year.
2 or more neurofibromas or one plexiform neurofibroma
optic nerve glioma
distinctive osseous lesion
sphenoid wing dysplasia
2 or more Lisch nodules
Axillary or inguinal freckling
Primary relative wit NF1
Risk factors for future haemorrage in brain AVM
Intranidal aneurysms,
Venous ectasia,
Posterior fossa location,
Previous haemorrhage
Epidermoid cyst vs arachnoid cyst
Epidermoid demonstrate diffusion restriction
Base of infundibulum lesion, isointense to brain on all images
Hypothalamic hamartoma/Tuber cinereum hamartoma
Cortical lesion, central high intensity on T1/T2 with low T2 rim
Cavernoma
Normal cranial suture width for 2YO
<1mm
Metabolic storage disease associated with
Macrocephaly
J shaped sella
Flattened tuberculum sellae, caused by:
Normal variant,
Optic chiasm glioma,
NF,
Achondroplasia,
Mucopolysaccharidoses,
Chronic hydrocephalus
Orbital pseudotumour
Low T1 and T2 signal in occular muscle, sparing tendons
Floating teeth causes
No obvious supporting bone for teeth.
Seen in:
Severe peridontal disease,
LCH,
Hyperparathyroidism,
Mets & myeloma
Frontal sinuses mucosal disease caused by obstruction at
Anterior hiatus semilunaris
Contents of jugular foramen
Pars nervosa:
Inferior petrosal sinus,
Glossopharyngeal nerve (CN 9)
Pars Vascularis:
Jugular bulb,
Vagus nerve (CN 10)
Spinal accessory nerve (CN 11)
