A matrix is an array of numbers in rows and columns. The horizontal lines in matrices are called rows and the vertical lines are called columns. A matrix with m rows and n columns is called an m-by-n matrix (or m * n matrix) and m and n are called its dimensions.
The matrix used in MRI determines the scan resolution. See Acquisition Matrix.

An uncharged neutral particle located in the nucleus of most atoms, which serves as a stabilizer.

Plural of spectrum. Spectra are components of the MR signal according to frequencies. Spectroscopy uses NMR spectral components to identify the metabolites, e.g. of the brain.

Generation of an electrical pulse, upon detection of a physiological signal, which can be used to initiate a synchronized data-acquisition pulse sequence.

(Å* or A*) A unit used to measure the wavelength of X-rays.
Definition: 0.1 nanometer or 10-10 meter.