SAR Calculations in MRI Scanning Systems [Health Effects]

The benefits of magnetic resonance imaging (MRI) have made it the radiological method of choice for a great number of diagnostic procedures. Aside from some acute potential risks such as those from aneurysm clips or certain metal objects in the patient's body or scanner environment, no adverse health effects have been associated with clinical MRI. To form images, radio frequency (RF) magnetic fields are used to excite and detect MR signals from body tissues. For the common 1.5 tesla (T) and increasingly 3.0 T clinical MRI scanners, the associated RF frequencies for proton imaging at 1.5 and 3.0 T are about 64 and 128 MHz, respectively.