Task 4 - Techniques of scanning Flashcards
Invasive
Procedure that enters body
- > usually by cutting or puncturing skin
- > interrupts normal bodily function
Non-Invasive
No break in the skin is created
Density reflects..
Reflects the structure of the brain
Blood flow reflects..
reflects metabolism of brain
Electromagnetic activity reflects..
the electrical activity of brain
Computerized Axial Tomography (CAT)
- noninvasive
- examine brain structure through analysis of X-ray absorption
- several positions around the head
advantages of CAT
3
-quick
-accommondates large patiens
-high spatial resolution
(LOWER THAN MRI)
-option 3D
disadvantages of CAT
2
- can damage DNA (bcs radiation)
- Medicore temporal Resolution
Positron Emission Tomography (PET)
- examine brain function
- info about blood flow and how our body’s using oxygen and sugar
- patients get radioactive bla injected into carotid artery
Advantage of PET
3
-High spatial reso
-helps doc to test for disease, how well treatment are working
(Cancer, heart, brain)
-Alzheimer, Parkinsons, seizure, stroke tumors
Image explanation of PET
– Each scan is a horizontal section
- during different cognitive or perceptual task
- Areas of high activity are reds and yellows.
Disadvantage of PET
3
-low temporal resolution
(Lower than MRI but better than CT)
-Does not provide images of brain structure Resolved by combining PET with MRI
-body stays radioactive for a short time
Transcranial Magnetic Stimulation (TMS)
- noninvasive
- stimulation of cortex through application of strong magnetic fields
- best scanning tech to treat depression
Magnetic stimulation
created to induce small electric current (compared to EEG) in specific parts of the brain
-> without causing seizure or loss of consciousness
pro TMS
-used to map behavior
-help with stroke rehabilitation
-parkinsoms
migraine, pain mamagement
cons TMS
-Low spatial resolution
-middle temporal resolution
- discomfort during the procedure
might faint or have a seizure undergoing stimulation.
-confusion related to disruptions in cognition, hearing or vision
Magnetoencephalography (MEG)
- passive and noninvasive
- Patiens wears helmet
- measures the tiny magnetic fields produced by active neurons
- identify regions that are active during a given task.
- localizes seizures in surgical treatments of epilepsy
- maps functional areas of brain (sensory motor, language, memo)
Pro MEG
-exellent temporal reso (advantage over fMRI)
-3D
-MEG fields pass through the head without any distortion.
(Advantage over EEG).
-Direct measure of brain function.
(Advantage over fMRI (indirect))
-most advamced method
Con MEG
lacks spatial resolutions
only magnetic signals near surface of brain can be recorded
Magnetic Resonance Imaging (MRI)
noninvasive
- uses magnetic energy to generate high-resolution images that reveal structural brain details
- used to detect anomalies in brain and spinal cord
pro MRI
-doesnt use radiation
-More detailed than CT scan->3D
High spatial resolution
con MRI
- difficult for ppl with metal in body
- size limits
- no temporal reso
