What does increasing the field of view (FOV) do to SNR?

Increasing the field of view (FOV) in MRI has a positive impact on the signal-to-noise ratio (SNR). When the FOV is expanded, it allows for a larger area of tissue to be sampled, which essentially gathers more signal from the protons in that area. The greater quantity of signal contributes to a higher SNR because SNR is defined as the ratio of the desired signal (from the tissue being imaged) to the noise (which is random and usually constant in the background).

As more protons are sampled across a wider area, the intensity of the signal collected increases, improving the clarity and quality of the images produced. This means that the images will display better contrast and detail, which is crucial for accurate diagnosis and assessment.

In summary, increasing the FOV enhances SNR by capturing more signal, leading to improved image quality, which is why this choice is the correct one. Understanding this principle is fundamental for optimizing MRI parameters in clinical practice.