General MRI Terms

Signal intensity
In MRI the terms low,  intermediate and high signal intensity are used. Depending on the scan protocol, tissue is imaged as white  (= high signal intensity), as a gray tone (= intermediate signal intensity) or as dark gray/black (= low signal intensity).

Gradient
An additional  magnetic field that  may be added  manually to the MRI device’s  magnetic field. This creates an additional subdivision in the ‘total’ magnetic field. Gradient coils are used among other things to determine the location of the protons in the X, Y and Z axis.

Sequence
Combination of radiofrequent pulses and gradients (= ‘added magnetic fields’),  which together constitute the building blocks for an MRI series. For instance, the terms ‘T1 weighted sequence’ and ‘T2 weighted sequence’ are used.