What is a major limitation of using a large coil in MRI?

The use of a large coil in MRI is associated with a major limitation of lower signal-to-noise ratio (SNR). While larger coils can capture more signal due to their size, they often result in a compromised SNR because they may pick up signals from a broader area, leading to more noise. This can dilute the desired signals from the specific area of interest, ultimately affecting the quality of the images produced.

In MRI, SNR is critical as it directly impacts the clarity and detail of the images. A lower SNR can lead to decreased image resolution and contrast, which can hinder accurate diagnosis and evaluation of conditions. Thus, while larger coils might provide some benefits, such as covering larger regions or accommodating larger patients, their result in lower SNR presents a significant challenge in medical imaging.