How can peripheral nerve stimulation discomfort be reduced during MRI?

Reducing peripheral nerve stimulation discomfort during MRI is crucial for patient safety and comfort. Spin echo pulse sequences are known to generate less peripheral nerve stimulation compared to other imaging techniques. This is primarily because spin echo sequences utilize a 90-degree excitation pulse followed by a 180-degree refocusing pulse, which helps to minimize high-frequency gradient activity that can lead to increased nerve stimulation.

Furthermore, spin echo sequences typically have longer TR (repetition time) and TE (echo time), which corresponds to a more gradual application of gradient fields. This slower rise and fall of the gradients reduce the rapid changes in magnetic field that can induce discomfort through peripheral nerve stimulation. By opting for spin echo sequences, the likelihood of generating higher gradient switch rates—responsible for discomfort—can be significantly diminished.

In contrast, other sequence types like gradient echo pulse sequences and EPI sequences can produce more pronounced gradient switching, which is associated with increased risk of nerve stimulation and patient discomfort. Steady-state sequences may not be as effective in minimizing this issue either, as they involve consistent and rapid gradient applications. Therefore, using spin echo pulse sequences is a reliable method for reducing peripheral nerve stimulation during MR imaging.