(W) The SI unit of power.
Definition: 1 watt is equal to a power rate of one joule of work per second of time or in electrical terms it is the power produced by a current of one ampere flowing through an electric potential of one volt.
Power is the rate at which work is done, or the rate at which energy is expended and is used both in mechanics and in electricity.
The unit is named for James Watt, a British engineer.

[Whole Body Radiation Counter] Very sensitive device intended to measure even the smallest amount of radionuclides in the entire body. Range usually from Bq to kBq. Heavy shielding is used to keep out naturally existing background radiation.

Whole body scintigraphy is the measurement of radioactivity in the entire body.
Whole body scintigraphy is useful for example in detection of tumors, infections, evaluation of metastases, and diseases with multiple organ involvement.
Different whole body scan techniques include:

The window width is the range of CT numbers or MR numbers displayed on the image monitor of the CT scanner. The difference between the maximum and minimum of the range is displayed as gray levels.