How can motion artefacts be effectively reduced in MRI?

Utilizing faster scan times is a common approach in MRI to minimize the duration of the examination, thereby potentially reducing motion artifacts. However, while this can limit the time available for patients to move, it may not suffice in all cases, as certain movements can still disrupt data acquisition within even a short scan time.

Changing the phase and frequency encoding directions is an effective strategy for motion artifact reduction. Motion artifacts can manifest differently depending on the encoding direction; therefore, altering these directions can help optimize the imaging sequence for individual patients. By using different gradient orientations, artifacts associated with specific motion patterns can often be diminished or redistributed, leading to clearer and more reliable images.

Increasing the acquisition matrix enhances the spatial resolution of the images but does not inherently address the issue of motion. In fact, a larger matrix may increase scan time, potentially exacerbating motion artifacts if the patient is unable to remain still for extended periods.

Using a lower magnetic field strength can impact image quality and signal-to-noise ratio, but it does not effectively mitigate motion artifacts. In fact, lower field strengths can lead to increased vulnerability to noise, which could complicate the interpretation of images.

Therefore, the correct answer is that changing the phase and frequency encoding directions is a key technique in reducing motion