(LET) Linear energy transfer is the ratio of energy transferred by an ionizing radiation traveling through a material per unit path length. LET depends on the kind of radiation, the density of the material, etc.
The higher the LET, the higher the biological damage through energy deposition along the particle track.

A linear grid consists of parallel lead stripes in one direction. The stripes are aligned with the long axis of the grid or the patient table.

(LI)A linear interpolator is a method to estimate the spiral CT scan data at a particular position along the patient's length by use of measured data points on either side.

Linearity is a property of a system, characterized by output that is directly proportional to the input.
In computed tomography (CT), linearity describes the amount to which the CT number of a material is exactly proportional to the density of this material (in Hounsfield units). This accuracy between the linear attenuation coefficient and the CT number is also utilized to describe the performance of a CT scanner.
The linearity of a gamma camera is a measure of the geometrical correctness of the images.

A logarithm is the exponent to which the base must be raised to produce a given number.
Logarithms are used to express dynamic processes, also in diagnostic imaging processes.



See also Algorithm, Integral, and Differential.