Imaging-Neuroanatomy Flashcards
How do you tell the difference between a brain CT and MRI?
On CT scans the bone comes out white, MR it comes out black. MR can be tricky because the scalp fat comes out white. Check this by looking for fat around the orbits, it there is fat, then you know it’s MR.
How do you tell if you are looking at a T1-weighted MR?
The white mater is white.
What type of image is this?
Black skull = MR. White mater is dark = Not T1-weighted. CSF & eye-balls are white = T2-weighted.
What type of image is this?
Black skull = MR. White mater is white = T1-weighted.
What type of image is this?
Black skull = MR. White mater is not white = Not T-1 weighted. CSF dark = Not T-2 weighted. The only options left are FLAIR, DWI or GRE. This is a FLAIR image.
What type of image is this?
Skull black = MR. White mater not white = not T-1. CSF black = not T-2. Fuzzy = DWI (diffusion-weighted image)
What type of image is this?
Skull black = MR. White mater not white = not T-1. CSF white = T-2. Fuzzy = ADC (apparent diffusion coefficient)
What images are people likely to show you if someone has had a stroke?
T-2 ADC or a DWI
What type of images are seen below in a patient with hydrocephalus and the normal patient?
Note that the white mater is white as well as the eye sockets, indicating a T-1 weighted MRI.
What is the difference between an intraaxial and an extra axial lesion?
An extraaxial lexion will be on the external surface of the gray mater.
Why are meningiomas considered grade I tumors?
They do not have a BBB and are on the outside of the gray mater. They are easily cured with surgical resection because they have a nice cleavage plane.
What are the sagittal landmarks you see in this T1-weighted MRI?
Clivus, Corpus Callosum, Cerebral Aqueduct and Straight sinus
What type of thrombosis does the patient have in the image seen below?
Superior sagittal sinus
Why might this patient have trouble seeing?
The pituitary adenoma compresses the optic chiasm.
What is causing the image seen below?
Note that in the gross picture, there is a region of unmyelinated brain tissue (possible Tuberous Sclerosis patient). This will have a stronger water signal on MRI that will show up whiter in the T2 image seen (darker in T1).
What structures are indicated in the images below?
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What gray mater structures are located around the image seen below?
Caudate nucleus, Lenticulate nucleus and Thalamus
An 8 year old girl comes to see you because she can’t see the blackboard. Her T1 MRI and CT scan are shown below. What is making it so she can’t see the blackboard?
A mass in the supra cellar cistern, note that the supra cellar cistern is missing in the axial view.
What landmarks has this epidural hematoma stopped progressing at?
The coronal suture and the lambdoidal suture.
How do you tell the difference between a subdural and an epidural hematoma?
Epidural: cannot cross suture lines, convex towards the brain, almost always come with a fracture, rapidly developing. Subdural: can cross suture lines, concave towards the brain, slower developing.
Where is blood accumulating in this patient?
This is a subdural hematoma. Notice that the CSF is squeezed out of the sulci
