Magnetic Resonance Imaging (MRI) Practice Test

Which technique is often used to mitigate chemical shift artifacts?

1. Fat suppression

2. Phase encoding

3. Frequency encoding

4. Parallel imaging

The correct answer is: Fat suppression

Fat suppression is a widely used technique in MRI to mitigate chemical shift artifacts. These artifacts occur due to the differences in resonance frequency between fat and water, which can lead to misregistration between fat and water-containing tissues, resulting in image distortion. By utilizing fat suppression techniques, the signal from fat is minimized or eliminated, allowing for clearer images of adjacent water-containing tissues. This is particularly important in areas where fat and water are in close proximity, such as in abdominal or musculoskeletal imaging. While other techniques like phase encoding, frequency encoding, and parallel imaging are essential in MRI for various purposes (such as affecting image resolution, reducing scan time, or improving signal-to-noise ratio), they do not specifically address the issue of chemical shift artifacts. Fat suppression specifically targets the unwanted signals from fat, thereby providing a more accurate representation of the anatomy being imaged.