CNS Imaging Flashcards
At which vertebra does the trachea bifurcates?
T4
Skull x ray indications
Bony abnormality - skeletal survey - radiopaque foreign bodies
Modality of choice in blunt polytrauma
CT scan
Better soft tissue characterization
MRI
Fast scan
CT
Used to detect areas of abnormal blood flow
Color doppler
It has a disadvantage that it is non reducible
Ultra sound
Head injuries are classified as
Closed - Penetrating
Lentiform, lens shaped biconvex, lemon shaped
Extradural hematoma
Crescent, moon shaped, concave, banana shaped
Subdural hematoma
90% is arterial (middle meningeal artery)
Extradural hematoma
Tear of the cortical veins
Subdural hematoma
Which of the following commonly associated with skull fractures?
- Extradural hematoma.
- Subdural hematoma.
Extradural hematoma
Common in infants and elderly (acceleration deceleration injuries)
Subdural hematoma
Traumatic spondylolisthesis of the axis (as a result of hyperextension and distraction)
Hangman fracture
Burst fracture of C1
Jefferson fracture
Stroke of an onset time of 0-6 h to 24h is considered ?
- Hyper-acute.
- Acute.
- Sub-acute.
- Chronic.
A
Stroke of an onset time of 24 h to 1 week is considered ?
Acute
Stroke of an onset time of 1 to 3 weeks is considered ?
Subacute
Stroke of an onset time of > 3 weeks is considered ?
Chronic
The goal of CT of the brain in the acute clinical setting is to
Exclude intracranial hemorrhage
Phases of ischemic stroke in CT
1- maybe normal within first 3-6 hs. 2- loss of insular ribbon sign. 3- Effacement of the lentiform nucleus. 4- Hyper dense MCA. 5- Sulcal effacement. 6- Cytotoxic edema (develops by 6 hs).
The most sensitive sequence for stroke imaging
Diffusion weighted imaging (DWI)
Sensitive to restriction of brownian motion of extracellular water
DWI
Which imaging modality has less risk and toxic effects to the kidneys?
- Brain MRI.
- Brain CT.
MRI (gadolinium contrast is better than the iodinated contrast)
According to the ACR criteria, what should be done in case of new focal neurological defect of less than 6 hours and is suspected for stroke.
CT head without contrast to asses for hemorrhage or large infarct
According to the ACR criteria, what should be done in case of new focal neurological defect of more than 6 hours and is suspected for stroke.
MRI head with and without contrast
According to the ACR criteria, what is the gold standard test for a clinically suspected hematoma?
CT head without IV contrast
Small infarcts of the distal distribution of the deep penetrating vessels is called
Lacunar infarcts (most are clinically silent)
Hypo dense area + peripheral rim enhancement is most likely
Brain abscess
The best imaging modality for multiple sclerosis
MRI
Most common type of brain tumors
Glioblastoma multiforme
The most common non glial cell tumor
Meningioma
The most common cancer to metastasize to the brain
Bronchogenic carcinoma
Lateral ventricles enlargement of the temporal horns is the best indicator for
Obstructive hydrocephalus
