Neuroimaging Flashcards
How is a bright signal referred to in a CT scan?
“dense”
How is a bright signal referred to in an MR scan?
“intense”
X-rays are also known as what?
Plain films, or radiographs.
Name some uses of CT scans.
Bone/calcium: fractures
Blood: especially recent trauma; acute subdural/subarachnoid hemorrhage
Memingiomas
Fat and orbital muscles
How does CSF appear in a typical CT scan?
black
What type of cut is not possible for a CT scan?
sagittal
What kind of base is used to contrast in a CT scan?
Iodine
What can you visualize when you use contrast in a CT scan?
blood vessels
What type of scan is preferred to evaluate intracranial pathology, and why?
MR: less radiation exposure than CT; greater soft-tissue contrast than CT
How are high water content areas shown in T1 weighted MRI images?
Dark (hypointense)
What would you use to contrast a T1 weighted MR?
Gadolinium
How are high water content areas shown in T2 weighted MRI images?
Bright (hyperintense)
What are T2 weighted images useful for?
pathology and edema
Which is the preferred imaging technique (CT or MRI) for head trauma?
CT
Which is the preferred imaging technique (CT or MRI) for lower cost?
CT
Which is the preferred imaging technique (CT or MRI) for subtle area of injury?
MRI
Which is the preferred imaging technique (CT or MRI) for brainstem or cerebellar lesion?
MRI
Which is the preferred imaging technique (CT or MRI) for fresh hemorrhage?
CT
Which is the preferred imaging technique (CT or MRI) for old hemorrhage?
MRI
Which is the preferred imaging technique (CT or MRI) when speed is needed?
CT
Which is the preferred imaging technique (CT or MRI) for skull fracture?
CT
Which is the preferred imaging technique (CT or MRI) for calcified lesions?
CT
Which is the preferred imaging technique (CT or MRI) for claustrophobic or obese patients?
CT
Which is the preferred imaging technique (CT or MRI) when there are metallic fragments in the heart or eye?
CT
Which is the preferred imaging technique (CT or MRI) when anatomical detail is needed?
MRI
Does MRI FLAIR more closely resemble T1 or T2? How is it different?
It more closely resembles T2, but water is dark.
What is MRI Flair useful for?
pathology, especially near CSF; MS plaques
What is MRI DWI useful for?
acute infarcts
What is Diffusion Tensor Imaging useful for?
Making maps of fiber directions to examine connectivity.
What are T1 weighted images useful for?
viewing anatomy
How can you remember T1/T2 bright vs dark?
T1 is for dark and T2 is for light, the “a” in dark being first alphabetically compared to “i” in bright.
