What effect does respiratory motion have on MRI image quality?

Respiratory motion is a critical factor in MRI imaging that can adversely affect image quality. When a patient breathes during the scan, the movement can create ghosting artefacts, which are unwanted repeating images in the final output. These artefacts arise because the MRI system captures signals from different parts of the anatomy at slightly different times, leading to misalignment and blurring in the resulting images.

Ghosting artefacts are particularly problematic in sequences where high spatial resolution is necessary, as they can obscure important anatomical details or diagnostic features. This makes it challenging for radiologists to accurately interpret the images, ultimately impacting patient care.

In contrast, the other options do not accurately reflect the impact of respiratory motion on MRI quality. It does not enhance clarity since movement typically leads to increased blurring and artefacts. While keeping the patient still may reduce motion effects, it does not completely negate the potential for motion-related issues, as any small shift can still affect the imaging process. Lastly, while respiratory motion can affect various signal types, it does not specifically target or primarily distort fat signals, as the overall impact is more generalized across the MRI images acquired during the breathing cycle.