How does a lower bandwidth affect chemical shift artifact?

A lower bandwidth has a significant impact on the presence of chemical shift artifacts in MRI imaging. When the bandwidth is decreased, the frequency differentiated between fat and water protons becomes narrower, which can lead to increased overlap of the signals from these two types of tissues. This situation causes the chemical shift artifact to become more pronounced because the frequencies of fat and water are closer together.

As a result, the misregistration of fat and water signals within an image is exacerbated, creating the appearance of false edges and boundaries between tissues. In contrast, increasing the bandwidth would spread out the frequency range used to capture signals, decreasing the likelihood of overlap and thus reducing the chemical shift artifact.

This understanding highlights the relationship between bandwidth settings and the way chemical shift artifacts manifest in MRI images, guiding technicians to adjust parameters accordingly to minimize such artifacts for clearer imaging results.