How is chemical shift calculated with regards to receiver bandwidth and pixel frequency range?

Chemical shift is an important parameter in MRI, particularly in distinguishing between fat and water signals due to their different resonant frequencies. Understanding how to calculate chemical shift involves recognizing the relationship between receiver bandwidth, image matrix size, and frequency range.

The correct choice indicates that the frequency range is determined by dividing the receiver bandwidth by the number of pixels in the image matrix. This is because the image matrix size defines how many total pixels will be present in the image, and each pixel has a specific frequency range it represents. Therefore, when the bandwidth is divided by the image matrix size, you yield the frequency range allocated per pixel. This is crucial for achieving accurate spectral resolution and distinguishing between closely spaced resonant frequencies, such as those of fat and water.

Other choices do not align correctly with the principles of chemical shift calculation. For instance, if the frequency range were doubled by the image matrix, it would imply an arbitrary amplification that does not reflect the physical relationships at play. Similarly, saying that the frequency range is equal to the receiver bandwidth fails to consider how the matrix size influences the resolution and representation of the frequencies. Lastly, stating that the frequency range is bandwidth multiplied by the field of view does not correlate with how frequency resolution is actually achieved in practice.