Imaging Techniques I Flashcards
What does fMRI stand for?
functional Magnetic Resonance Imaging
What does PET stand for?
Positron Emission Tomography
What does MRT stand for?
Magnetic Resonance Tomography
What does EEG stand for?
ElectroEncephaloGraphy
What does MRI stand for?
Magnetic Resonance Imaging
What does NMRI stand for?
Nuclear Magentic Resonance Imaging
Name two disadvantages of PET?
expensive
complex mathematics
What does SPECT stand for?
Single-Photon Emission Computed Tomography
What does NMR stand for?
Nuclear Magnetic Resonance
This is a physical phenomenon used in NMR-Imaging techniques.
What does BOLD stand for?
blood-oxygen-level-dependent
What does fMRI primarily measure?
the BOLD contrast
What is the BOLD contrast based on?
the change in magnetization between oxygen-rich and oxygen-poor blood
Can fMRI theoretically use other biomarkers than the BOLD signal?
Yes, and there is research going on in this field (aim: improve spatial and time resolution).
Arterial blood is oxygen-rich or oxygen-poor?
Oxygen-rich
Venous blood is oxygen-rich or oxygen-poor?
Oxygen-poor
What is measured in EEG?
Voltage fluctuations resulting from ionic current flows within the neurons of the brain.
What does CT stand for?
Computed Tomography
What does CAT stand for?
Computed Axial Tomography
On what is CT and CAT based?
x-rays
What does MRI use to take measures?
magnetic fields and radio waves
What do MRI techniques not use (which is good!)?
X-rays and radioactive tracers
What does MEG stand for?
Magnetoencephalography
How does MEG work?
it measures the magnetic fields produced by electrical activity in the brain via extremely sensitive devices
MEG: what about spatial and temporal resolution?
High temporal resoltution
Low spatial resolution
How does PET work?
PET measures emissions from radioactively labeled metabolically active chemicals that have been injected into the bloodstream.
What has to be done prior to a PET session?
The positron emitting radioisotopes used are produced by a cyclotron, and chemicals are labeld with these radioactive atoms. This labeled compound, called a radiotracer, is injected into the bloodstream and eventually reaches the brain.
Advantages of PET?
- High resolution
- Speed of Completion
Biggest drawback of PET?
It is limited to monitoring short tasks.
How does SPECT work?
Like PET, but using gamma ray emitting radioisotopes and a gamma camera.
Why is it cool that PET works with different compounds as a radiotracer?
Because of that PET has the advantage of being able to identify specific brain receptors associated with particular neurotransmitters.
