Physics curriculum

The physics curriculum is one of our curriculum articles and aims to be a collection of articles that represent core physics and imaging technology knowledge:

• physics and imaging technology: x-ray
• physics and imaging technology: ultrasound
• physics and imaging technology: CT
• physics and imaging technology: MRI
• physics and imaging technology: nuclear medicine

We've just started working on this, so only MRI is present at the moment.

MRI

Basic nuclear magnetic resonance (NMR)

• magnetism
  • magnetic dipole
  • magnetic dipole moment
  • diamagnetism
  • paramagnetism
  • ferromagnetism
  • superparamagnetism
  • magnetic field
    • magnetic field strength
• nuclear magnetization
  • precession
  • Larmor frequency
  • relationship between Larmor frequency and magnetic field strength
  • gyromagnetic ratio
  • parallel and antiparallel orientation
  • quantum mechanical description of NMR
  • energy difference between spin up and spin down states
• tissue magnetization
  • dependence of magnetization on proton density (PD), field strength and temperature
  • magnetic susceptibility

RF excitation

• nuclear magnetic resonance
  • radiofrequency (RF) radiation
  • flip angle
  • longitudinal and transverse magnetization
• free induction decay (FID)
  • electromagnetic induction
  • RF coils

Relaxation processes

• longitudinal (T1) relaxation
  • typical T1 values
  • factors affecting T1
• transverse (T2) relaxation
  • typical T2 values
  • factors affecting T2
• T2* relaxation
  • magnetic field inhomogeneity
• molecular tumbling rate effects on T1 and T2
• paramagnetic contrast agents
• the chemical shift

Simple pulse sequences ​

• spin-echo (SE)
  • time to echo (TE)
  • repetition time (TR)
  • T1, T2 and PD-weighted SE images
  • fast spin echo (FSE)
• inversion recovery (IR)
  • inversion time (TI)
  • short-tau inversion recovery (STIR)
  • fluid attenuated inversion recovery (FLAIR)
• gradient-recalled echoes (GRE)
• echo planar imaging (EPI)

Production of the Image

• magnetic field gradient
  • Fourier analysis
  • slice selection gradient
  • effect of gradient strength and bandwidth on slice thickness
  • frequency encoding gradient
  • phase encoding gradient
• Fourier transformation
  • inverse Fourier transformation
  • K-space

​Instrumentation

• magnet types
• superconducting MR magnet
  • cryogenics
  • magnetic quench
  • magnetic field homogeneity
  • magnetic shimming
• gradient coils
  • Helmholtz coils
  • saddle coils
  • slew rate
  • eddy currents
• RF coils
  • RF transmitter
  • RF receiver
  • volume coils
  • surface coils
  • quadrature volume coils
  • phased array coils
• RF shielding
  • Faraday cage
  • RF leakage
• magnetic shielding
  • fringe field

Advanced MRI

• diffusion weighted imaging (DWI)
  • apparent diffusion coefficient (ADC)
• MR angiography (MRA)
  • time of flight (TOF)/flow-related enhancement (FRE)
  • phase contrast imaging
• functional MR imaging (fMRI)
  • BOLD (blood oxygenation level dependent) imaging
• magnetization transfer contrast
  • magnetization transfer ratio
• magnetic resonance spectroscopy (MRS)
• PET-MRI

Image quality and safety

• tissue contrast
• voxel size
• signal-to-noise ratio (SNR)
  • image averaging
• artifacts
  • chemical shift artifact
  • truncation artifact
  • wrap-around artifact
  • ghost images
  • magic angle artifact
• MRI safety
  • induced current
  • screening of patients and staff
  • external equipment and implanted devices
  • RF heating
    • specific absorption rate (SAR)
  • MRI safety zones
    • missile effect
  • MRI acoustic noise
    • hearing protection
  • quench response plan
  • contrast media safety