Decimation is the reduction of data at the digitized signal. Fewer samples are used to represent the detected signal. The opposite process is called interpolation, more samples are added.

See also Digital Radiography, and Digital Subtraction Angiography.

Decontamination is a process to reduce or remove unwanted material, such as radioactive, toxic chemical or biological substances. Decontamination from the surface of an object or from an area applies to removal by washing, biological agents, chemical action, mechanical cleaning, or other techniques.

The deep dose equivalent is related to the dose in tissue at a depth of one centimeter due to external radiation. Also called personnel dose equivalent at a depth of 1 cm. The unit for deep dose equivalent is J/kg or sievert (Sv).

A defibrillator is a medical device used to re-establish the normal heartbeat with a jolt of electricity. Implantable cardioverter defibrillators (ICDs) are small devices that are placed below the collarbone and via wires, or leads continuously monitor the heart's rhythm.

(DGNAA), see Neutron Activation Analysis.