Which techniques can be used to reduce patient heating during MRI?

The use of alternating between spin echo and gradient echo sequences can effectively reduce patient heating during MRI. This approach takes advantage of the differing mechanisms of image formation and energy deposition associated with these sequences.

Spin echo sequences typically result in lower specific absorption rate (SAR) values because they require fewer RF pulses, thus decreasing the energy deposited into the patient’s body. Gradient echo sequences, while often faster, can lead to higher RF energy exposure due to their reliance on a gradient field which can generate increased heating. By alternating between these sequences, the overall thermal load can be managed more effectively, allowing the MRI system to balance image quality and patient safety regarding heat generation.

The other techniques presented are less effective or may even contribute to increased patient heating. For example, increasing the flip angle generally leads to increased RF power, which raises patient heating. Using a single shot spin echo sequence may improve scan efficiency but doesn't inherently reduce heating. Similarly, increasing repetition time (TR) can be beneficial in some aspects but does not directly translate to a reduction in heating as the longer TR could also lead to prolonged exposure depending on other sequence parameters and the specific situation.

Thus, alternating between spin echo and gradient echo sequences stands out as a practical technique in managing patient heating effectively in MRI