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 have 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 magnetisation

  • 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 magnetisation

  • dependence of magnetisation on proton density (PD), field strength and temperature

  • magnetic susceptibility

RF excitation

• nuclear magnetic resonance

  • radiofrequency (RF) radiation

  • flip angle

  • longitudinal and transverse magnetisation

• 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

• magnetisation transfer contrast

  • magnetisation 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