Neuroradiology Flashcards
Sagital image: what is fourth ventricle?
Triangle shaped structure between spinal cord and cerebellum
What is the vermis?
Midline part of cerebellum that is covering the fourth ventricle
What is best for rapid imaging of patients with hemorrhage or mass effect?
CT
What is more sensitive for subtle findings, but requires longer imaging times?
MRI
Describe the neuroradiology of MS?
- MRI is preferred imaging modality
- White matter lesion known as plaques show
- Contrast used to assess activity : Areas called active lesions
Describe the pathology of MS:
- Immune mediated disease where body starts to attack myelin
- Damaged myelin leads to scar formation (sclerosis) which impairs nerve impulses
- Thought to be related to environmental factors in genetically susceptible patients
Encephalitis?
Infection of brain itself
Abscess in brain?
More focal walled off collection - infection walled off
What happens in a Subarachnoid Hemorrhage?
- Most commonly related to ruptured aneurysm
- Leads to sudden, severe headache, with loss or impairment of consciousness
- If CT negative with strong suspicion may need LP
Where is the thalamus on the axial section?
Lateral to the 3rd ventricle
When detecting stroke or heart attack, what imaging modality is used first?
CT
***What are risk factors for infarction?
- Atherosclerosis (fat and other substances build up in the walls of the arteries)
- High BP
- Diabetes mellitus
- Tobacco use
- Obesity
- Elevated lipids
What is intraparenchymal?
Occurring in the body of an organ
What is an infarction?
- Caused by blockage in the blood supply
- It can be caused by thrombosis (blockage of vessel due to formation of a clot) or embolism (blockage travels from elsewhere)
How can you tell if you’re look at a CT or MRI?
- MRI has more detail, can tell white from gray matter - well differentiated
- CT - bones look white
What is MRI good for?
- Best way to assess for acute ischemic changes or infarction
- Special sequences that identify infarcts with in hours
- Best way to assess for demyelinating disease, tumors, or seizure foci
Why should you always get CTs without contrast for acute traumas?
-Contrast material appears white/dense and acute hemorrhage on a CT is dense (looks white)
When should you use contrast?
- Infection, inflammation and tumor which can all disrupt the BBB
- You can better see the process and its effect on the BBB if you use contrast
What happens in a Neonatal US?
- One at 20 weeks used as a screening exam
- Visualization of normal lateral ventricles, normal cavum septum pellucid (below/between lateral ventricles) and a normal appearing posterior fossa can exclude a vast majority of congenital CNS abnormalities
What does the corpus callous do?
- Connects the two hemispheres
- Parts: Rostrum, genu, body and splenium parts
What is suli?
Depressions in brain, fluid filled
What images are used to make diagnoses most often?
Axial/transverse
Where is the cerebellar vermis?
-Bottom, back/posterior of the cerebellum
What uses ionizing radiation?
CT
