CNS Flashcards
Pilocystic astrocytoma
Modality
We must take biopsy
- pre & post contrast CT
- MRI T1 brain axial with IV contrast
RT infratentorial intraaxial cystic lesion with mural enhancement
No need for biopsy !!!
CT brain axial with contrast
Ring enhanced lesion in left frontal lobe with contralateral vasogenic edema
Dx :
Can also be described as :
Typical for Glioblastoma
Lt glioblastoma
Heterogenous enhanced mass in corpus callosum
Ring enhanced lesion with vasogenic edema
“ check for subfalcine herniation “
Next step is biopsy
Brain tumour
With bilateral ring enhanced lesion in corpus callosum surrounded by vasogenic edema
Dx :
Sign :
Glioblastoma
Butterfly sign
-
Malignant cells invade the BBB
Or abscess
Meningioma
Most common site :
Type of enhancement:
Parasagital “ at cerebral convexities
Homogenous enhanced mass
“ may contain calcium “
-
Rat tail sign
Claw sign
+ broad base
-
Meningitis
Meningioma
Meningioma
Extra or Intra axial ?
Extra axial
If meningioma surrounded by vasogeniv edema =
Malignant meningioma
Calcium way of appearance on
CT
MRI
CT : white as skull
MRI : mass appear heterogenous
Differences between ring enhanced lesions in the brain :
Abscess
Thin regular wall , multiple : adjacent to each other
Glioblastoma : single thick irregular wall
Metastasis : single in cerebellum , multiple : away from each other
Suspect brain metastasis
Next step is :
CXR ; the commonest tumour is lung cancer
CT brain axial with IV contrast
Multiple enhanced lesions , one of them shows ring enhancement located in the cerebellum & basal ganglia
Dx is :
Metastasis
Acoustic shwannona
Arise from …..
Myelin sheath of the 8th Cranial nerve
Left CPA enhanced extra axial mass
History of sensorineural deafness
Dx :
Acoustic neuroma
Pre & post contrast CT brain axial
Show heterogenous enhanced extra axial mass
Ddx :
Acoustic shwannoma
Meningioma
Ependymoma
Neuroepithelial cyst
Heterogenous enhanced mass at CPA
Can be
- acoustic shwannoma
- meningioma “ with Calcium “
The most common intracranial malignancy in adults is ………
Brain metastasis
Pituitary adenoma
Can be
Micro …
- non enhanced
- dx by ….
Most common disturbance …..
Macro ….
-enhanced
-dx by ….
- complain of ………
Micro <1cm
MRI only
Secondary amenorrhea
Macro >1cm
CT or MRI
-no hormonal alteration
Pressure symptoms = high ICP compressing carotid arteries & optic chiasma “ bitemporal hemianopia
Large homogenous enhanced mass occupying sella turcica
Ddx :
Dx :
Pituitary macroadenoma , meningioma
Dx : pituitary macroadenoma
Large mass occupying sella turcica with mass effecy on optic mass
MRI T1 brain axial with IV contrast
Describe acute bacterial meningitis
Leptomeningeal enhancement , hydrocephalus
Leptomeningeal enhancement with pus
Dx : bacterial meningitis complicated by empyema
Modalities used :
MRI T1 axial with IV contrast
MRI diffusion weighted image
MRI T1 axial brain with IV contrast
Basal enhancement witg microabscesses.
Dx :
Tubercuolous meningitis
Describe viral meningitis :
CT axial brain with IV contrast
Hypodense edema , sulci effacement
Describe
Brain abscess :
Management :
CT brain axial with IV contrast ring enhanced lesion in RT frontoparietal lobe surrounded by vasogenic edema
Antibiotic & drainage
Ring enhanced lesion in brain
Abscess
Or
Tumour “ metastasis”
Absecess close to each other
Metastasis away from each other
CT = no hge > exclude ……
Ischemic stroke =
Early “ before 6 hours :……..
6-12 hrs : ……
Hemorrhagic stroke
CT normal
Dense artery sign : cytotoxic edema lead to
Sulci effacement ; poor differentiation between grey & white
Dense artery
Sulci effacement indicate :
Hyperacute ischemic stroke
Hyperacute I S :
Describe
CT brain axial without Iv contrast
Dense artery sign , sulci effacement
Finding follow right middle cerebral artery territory
Acute ischemic stroke
describe
Wedge shaped edema follow Lt middle cerebral artery territory
Encephalomalacia follow MCA terrirory
Lt chronic ischemic stroke
No need for Treatement
Diagnosis of ischemic stroke within 30 min from onset of symptoms can be done by :
Diffusion weighted imaging
-
-
-
Intraventricular hemorrhage
Subarachnoid hemorrhage
Acute parenchymal hemorrhage
Acute pontine hemorrhage
Most common cause of hemorrhagic stroke :
Other causes :
HTN
At basal ganglia
Arteriovenous malformation rupture
Cancer
Berry’s aneurysm
Bleeding disorder
H/O of chronic headache
Carotid angiogram
Digital subtraction angiogram
Dx of ….
Complications:……
Arteriovenous malformation
Rupture & hemorrhagic stroke
Berry aneurysm can be diagnosed with ……..
Complication ……
Digital subtraction angiogram DSA
Rupture & hemorrhagic stroke
CT brain axial without IV contrast
Hyperdense parenchymal hemorrhage occupying left basal ganglia
Dx :
Most like cause :
Left acute parenchymal hemorrhage
Hypertension
Hyperdense hge occupying the sulci
Dx :
Subarachnoid hge
Parenchymal hemorrhage with vasogenic edema
Most like the cause is :……
Cancer
Hyperdense hge occupying the pons
Acute pontine hemorrhage
Most common sites of diffuse axonal injury :
Junction between white & grey matter
Corpus callosum
Basal ganglia
Brian stem
Brain contusion appear as
Can be
Hemorrhagic foci always acute
Coup , counter coup or both
Diffuse axonal injury diagnosed by :
Hypointense dots
MRI T2 star
Appear as hypointense dots
Signs of acute ischemic stroke
Dense artery sign
Poor differentiation between grey & white matter
Sulci effacement
