Revision Flashcards
What element in the body is targeted during an MRI scan?
Hydrogen
What is it about oxygen that makes it the one that is targeted?
There is so much of it in the Body
Why do nuclei with and uneven number of protons and neutrons interact with a magnetic field?
They act like mini magnets
How is a very large magnetic field created in an MRI?
Superconducting magnet
The magnetic nuclei align their nuclear skins in a direction parallel to the magnetic field. A piece of equipment is used to excite the Low energy nuclei to a higher state that the others. What is the piece of equipment called?
Radio frequency coils
What is the name given to the frequency at which nuclei can absorb energy?
Larmor frequency
What follows the period of excitement?
Relaxation time
What is the form of energy released during the period after excitement?
Radio waves
How is the origin of the signal found?
Gradient coils
State the necessary precautions that must’ve taken before entering an MRI room?
No metallic objects No pacemaker No coins No jewellery No credit cards No tattoos
Why might a patient be uncomfortable or experience discomfort when in an MRI scan?
Very loud
Claustrophobic
Takes long
What are the features on an MRI scan that make the technique useful in medical diagnostics?
Very clear images (more detail)
Non ionising
Two types of thermometers?
Digital thermometer (thermistor) Digital infrared sensor (tympanic thermometer)
How do you use a digital thermometer?
Used in mouth, armpit or rectum
How do you use a digital infrared sensor?
Detects infrared waves when placed in ear