Neuroimaging Flashcards
For patients with operable pathology, what information can imaging provide?
- Where the abnormality is located.
- The extent of the pathology (“how bad”)
- What structures are associated/at risk.
Distinguish between SPGR and FLAIR.
Both are imaging modalities that reflect different tissue parameters.
FLAIR highlights bound water in tumors as well as associated edema.
Since SPGR gives finer detail to the normal brain structures, they may be combined in threshold SPGR+FLAIR imaging.
What is a voxel?
A 3-dimensional functional unit of resolution, effectively analogous to the 2-dimensional pixels on a computer display.
How does fMRI/BOLD highlight “active” regions of the brain?
Active brain is metabolically active and requires greater blood flow. This is detected by MRI which looks for signal from H2O.
Furthermore, deoxygenated hemoglobin disrupts this signal–resting tissues remain dark.
What is the significance of diffusion tensor imaging (DTI)?
What useful information is provided in presurgical mapping?
DTI is an imaging modality that reveals brain architecture by tracking the diffusion of water in the brain. It is useful in presurgical mapping to reveal white matter tracts.
Presurgical mapping is important to identify nearby structures. This reveals what could be at risk in surgery, whether or not the tumor is operable, etc, as well as facilitates planning route of access.
Describe the role of neuroimaging in thereapeutic stimulation therapy.
fMRI can guide the placement of electrodes–where the site of interest is, where is a safe entry point.
What are the applications of imaging during surgical procedures?
They can provide tracking of surgical instrument, provide multiple angles of imaging, etc. They can also guide the precise targeting of radiation treatment.
