Neuroimaging Essentials Flashcards
What are the advantages of MRI?
– Best imaging of brain and spinal cord
– Multiple views (axial, sagittal, coronal) available
– No radiation exposure
What are the disadvantages of MRI?
– Longer scanning time, images degraded by patient movement
– Prohibited in presence of pacemakers or certain implanted metal
– Tight, enclosed scanner is difficult for claustrophobic patients
What are the advantages of CT?
– Shorter scanning time (advantages for unstable or agitated
patients)
What are the disadvantages of CT?
– Radiation exposure
– Axial views, needs image reformatting to obtain other views
What is the contrast agent in MRI?
Gadolinium
What is the contrast agent in CT?
Iodine
T1W MRI
Highlights anatomy with CSF being dark
T2W MRI
Highlights pathology with CSF being bright
FLAIR MRI
Fluid Attenuation Recovery - similar to T2W but high signal bright CSF is removed
What type of MRI will lesions be bright on?
- T2W
- FLAIR
How does acute hemorrhage change on a CT scan over time?
Starts hyper dense and eventually becomes isodense and then hypodense (black)
What is the best imaging for acute infarction?
Diffusion Weighted MRI
DWI
What will be enlarged in cerebral aqueduct stenosis?
- 3rd Ventricle
- Lateral Ventricles
NOT the 4th ventricle
