A SAR at 3T will produce ___ heating than a 1.5T given the same sequence parameters.

The specific absorption rate (SAR) is a measure of the rate at which energy is absorbed by the body when exposed to an electromagnetic field, such as that used in magnetic resonance imaging (MRI). The SAR is determined by the strength of the magnetic field and the specific sequence parameters being utilized during the MRI scan.

At a higher magnetic field strength, such as 3T compared to 1.5T, the energy absorption increases due to the relationship between field strength and SAR. In general, the SAR is proportional to the square of the magnetic field strength (B²). Therefore, when moving from a magnetic field strength of 1.5T to a higher strength of 3T, the increase in SAR can be calculated using the square of the increase in field strength.

In this case, moving from 1.5T to 3T represents a doubling of the magnetic field strength (3T is twice the field strength of 1.5T). When the field strength is squared (2²), the increase in SAR becomes fourfold. This means that for equivalent sequence parameters, the SAR—and therefore the corresponding heating effect—at 3T is four times greater than that at 1.5T.

Thus, the correct