Magnetic Resonance Imaging (MRI) Practice Test

What is the primary goal of slice selection in MRI?

1. To enhance signal-to-noise ratio

2. To define voxel volume

3. To isolate the area of interest

4. To improve contrast resolution

The correct answer is: To isolate the area of interest

The primary goal of slice selection in MRI is to isolate the area of interest. During the MRI scanning process, slice selection is a crucial step that allows the system to target specific anatomical slices of the body while suppressing signals from surrounding tissues. This isolation is achieved by applying a specific frequency gradient during the radiofrequency pulse, which ensures that only spins within a designated slice of tissue receive the excitation signal. As a result, only the protons within that particular slice are excited to produce a measurable signal, allowing for precise imaging of the targeted area. While enhancing signal-to-noise ratio, defining voxel volume, and improving contrast resolution are important aspects of MRI, they are not the primary objective of slice selection. Instead, those factors typically relate to the overall quality of the MRI images and may be affected by various scan parameters and techniques, but they do not specifically pertain to the selective imaging capability that slice selection provides.