Electromagnetic fields

The Radio Frequency (RF) field is an oscillating electromagnetic field. Pulses of RF energy are used to generate the signal, which cause tissues to absorb RF power. Under certain conditions, this may cause tissue heating. The amount of heating depends on several factors, such as patient size and pulse sequence timing. RF heating of tissues is greatest at the periphery of the skin. The Specific Absorption Rate (SAR) is the estimated amount of heat dose received by the patient. This value is expressed as watts of power per kilogram of the patient’s body weight.