magnetism
Magnetism is a property of matter that is a result of the orbiting electrons in atoms. The orbiting electrons cause the atoms to have a magnetic moment associated with an intrinsic angular momentum called spin.
Magnetic field strengths are measured in tesla (T), a derived SI unit. The equivalent, and superseded, cgs unit is the gauss (G); one tesla equals 10,000 gauss. The earth's magnetic field is about 31 microtesla. The strength of electromagnets used to pick up cars in junk yards is about the static field strength of most MRI machines (1.5-2.0 T).
You will run across four terms describing the magnetic properties of materials, such as contrast agents, used in MRI. These terms are:
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Imaging physics
- imaging physics
- imaging in practice
- imaging technology
- x-ray physics
- ionizing radiation
- interaction with matter
- x-ray spectrum
- radiation units
- effective dose
- exposure
- legacy units
- radiation safety
- radiation damage (biomolecular)
- radiation damage (skin injury)
- stochastic effect
- CT physics
- MRI physics
- B0
- chemical shift
- dependence of magnetization (proton density, field strength and temperature)
- echo time
- eddy currents
- electromagnetic induction
- Ernst angle
- flip angle
- Larmor frequency
- magnetic dipole magnetic field gradient
- magnetic susceptibility
- magnetism
- molecular tumbling rate effects on T1 and T2
- net magnetization vector (NMV)
- relaxation
- repetition time
- resonance and radiofrequency (RF)
- units of magnetism
- ultrasound physics
- absorption
- acoustic impedance
- attenuation
- beam focusing
- beam steering
- decibel
- Doppler effect
- dynamic range
- focal zone
- frame rate
- gain
- line density
- piezoelectric effect
- power output
- reflection
- refraction
- scattering
- time gain compensation
- ultrasound frequencies
- nuclear medicine physics
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