Neuroradiology Flashcards
What are common indications to perform a CT scan?
Head trauma Acute stroke Headache : red flags for suspected tumour or subarachnoid haemorrhage Cancer Post surgical
Reasons not to perform a CT scan?
Ð If the patient is GCS 15,
- no suspected open or depressed skull fracture,
- no haemotympanum,
- no ‘panda’ eyes,
- no CSF leakage from ears or nose,
- no post-traumatic seizure,
- no focal neurological deficit,
- <2 episodes of vomiting,
- no amnesia, age < 65 years,
- no coagulopathy,
- not struck by a motor vehicle,
- not ejected from a motor vehicle,
What is the imaging technique of choice for seizures?
MRI
Is complete recovery after a seizure epilepsy?
No
Need to have recurrent
What are indications to perform an MRI?
Demyelination for example MS diagnosis CNS tumours Spine for intervertebral disc prolapse TIA Epilepsy Paediatric neurology Headache
When do you not do an MRI?
Implanted electronics (most cardiac pacemakers, implantable defibrillators, cochlear implants) Aneurysm clips Heart valves Claustrophobia Pregnancy Tattoos
What is angiography used for in neurological pathology?
Aneurysm
Arteriovenous malformation
Carotidocavernous fistula
Unstoppable epistaxis
What is perfusion?
Defined as the volume of blood passing through a defined volume of tissue per unit time
What are neurological disorders of abnormal perfusion?
Stroke
Tumour
What is a PET scan usually used for?
To map out glucose usage
To see where there is increased metabolism in cells
Useful for cancer staging
What colour are bones in plain radiographs?
White
What are the advantages of a plain radiograph?
Almost universally available
Fast
Sequential images in subtraction angiography
What are the disadvantages of plain radiograph?
Lacks soft tissue detail
What are the advantages of CT?
Rapid
Metal and pacemaker tolerance
Good for demonstrating acute haemorrhage
What are the disadvantages of CT?
Radiation exposure
more expensive cumbersome equipment
What are the two types of MRI?
T1
T2
What are the advantages of MRI?
No radiation
Soft tissue differentiation
Physiological information
What are the disadvantages of MRI?
- Poor tolerance of metalwork
- Magnetic sensitive electronics may fail or are contraindicated
Pacemakers
Cochlear implants absolutely contraindicated - Least movement tolerance
- Slow, must limit sequences
- Most expensive equipment
- Danger of metallic object becoming projectiles
What are the advantages of US?
No radiation
Less expensive equipment
Can be performed in the neonatal unit
Movement intolerant
What are the disadvantages of US?
Requires a wide enough open fontanelle
Image quality and interpretation based on operator skill
What are the advantages of radionuclide radiology?
Physiological information
Glucose metabolism
Perfusion
Dopamine reuptake receptors
What are the disadvantages of radionuclide radiology?
Unclear anatomical information
Medium cost equipment
Radiotracers can be expensive
What are important neurological emergencies?
Trauma
Acute stroke
Cauda equina syndrome
Subarachnoid haemorrhage
