Fog in radiology refers to darkening of images by sources other than the radiation of the primary beam to which the film was exposed. This can be due to chemicals in the processing solutions, light, or non primary beam radiation.

(FDA) An agency of the US federal government established by Congress in 1912 and presently part of the US Department of Health and Human Services. The FDA gives classifications of medical devices according to potential risks and controls the safety of marketed drugs.
For more details please visit the FDA's 'Our Mission and Mandate'.

See also Class I II III Devices and Phase 1 2 3 4 Drug Trials.

(FORmula TRANslating) Programming language developed in the 1950s by IBM, used today mainly for scientific programming.

(FT) The Fourier transformation is a mathematical procedure to separate out the frequency components of a signal from its amplitudes as a function of time, or the inverse Fourier transformation (IFT) calculates the time domain from the frequency domain. Fourier transformation analysis allows spatial information to be reconstructed from the raw data.

Fractionation is the delivery of a given total radiation dose as several smaller doses, separated by intervals of time to minimize side effects.