Magnetic Resonance Imaging (MRI)

Flashcards about Magnetic Resonance Imaging (MRI)

Magnetic Resonance Imaging (MRI)

Noninvasive and safe imaging technique that provides full 3D images with excellent soft tissue contrast. It's very versatile, offering different contrasts, and measures the magnetic moment of positively charged nuclei of the hydrogen atom in a water molecule.

Magnetic Moment

The magnetic dipole created by the 'intrinsic angular momentum' or spin of subatomic particles.

Tesla (T)

The unit of measurement for the magnetic field (B0) in MRI.

Bulk Magnetization (M)

The small net magnetization created when the magnetic moments of hydrogen nuclei align with or against the B0 field, with slightly more aligning 'up'.

Precession

The rotation of an object around the direction of an applied force when it is spinning (has angular momentum).

Gyromagnetic Ratio (𝛾)

The ratio of the magnetic moment to the angular momentum of a particle. Higher 𝛾 means faster precession.

Faraday's Law of Induction

Changing magnetic field induces an electromotive force (a current) in a conducting wire.

Larmor equation

𝜔 = 𝛾.B0, used to calculate precession frequency it states that precession frequency will be equal to bulk magnetisation strength times the gyromagnetic ratio