Brain scans Flashcards
PET SCANS - what are patients injected with?
Radioactive tracer
PET SCANS - what happens when the radioactive tracer is injected?
- uptake of oxygen in the water or glucose happens
- tracer decays it emits positions
what are PET scans used for?
To identify damage or tumors and show malfunction via levels of activity
PET SCANS - what happens when positions are emitted?
- they collide with electrons
- giving gamma rays
- this produces an image
PET SCANS - what do the ppts do when injected with the tracer?
They are given a task to stimulate the parts of the brain they wish to look at
PET SCANS - why might the researcher want to detect damage or abnormal activity?
- to show where problems exist
- predict what kind of issues patients might face in relation to the brain activity shown
what does PET scans stand for?
Posistron emission Tomography
what does fMRI scans stand for?
Magnetic resonance imaging
what do fMRI scans do?
They enable images of brain activity to be gathered without the use of radiation
fMRI scans - what is the idea behind this technqiue?
- associated with blood flow in the brain
- used to produce still images of the brain
How do fMRI scans actually work?
- patient is placed in a large scanner
- strong magnetic field through the head
- nuceli of some atoms in certain molecules spin a certain way placed against a magnet which gives the still images
- nuceli emits hydrogen concentrations in diff areas which produce the detail of a scan
- as neutral activity increases in the brain, blood flow increases in the active areas to keep up with the demand for oxygen. The oxygen repels a magnetic field but when it has been deoxygenated it will follow the direction of the magnetic field and it is these changes that the scanner will detect to create an image.
Why are fMRI scans used?
- They allow us to see the structure of the brain and whether the damage of the tumours need treatment. The scanner sends the information to a computer that is able to create a map of activation to show the changing levels of activation to show the changing levels of neutral activity in different brain areas as tasks are being completed.
What are CAT scans used for?
- They can be used to take images of any part of the body including the brain. CAT scans are very quick to conduct and can give accurate details of the brain structure which can help guide clinicians in decision making regarding treatment or surgery.
How do CAT scans work?
- CAT scans of the brains involve passing x-rays into the head, multiple beams are passed around the head from different angles to gather more information as when scanning something as complex as the brain more information is needed.
- The information from the multiple x-rays beams is interpreted by a computer and a detailed image of the structure of the brain can be seen. This is useful for detecting areas of the brain damage following an accident or positioning of tumors in the brain.
What does the use of CAT scans involve?
- Involve exposure to radiation and it is advised that they are only use when the possible benefits in relation to diagnosis outweigh the potential risks.
