What is the primary effect of increasing the number of frequency encoding steps?

• A. Increased SNR
• B. Increased scan time
• C. Decreased resolution
• D. Decreased signal clarity

Answer: (B)

Increasing the number of frequency encoding steps primarily results in an increase in scan time. Each frequency encoding step corresponds to a data acquisition point during the imaging process. By increasing the number of steps, the system collects more data to enhance the image quality and detail, but this also means that the total time required to obtain the complete dataset for the image is longer.

This increased scan time is a critical consideration in MRI procedures, as it can affect patient comfort and throughput. In practice, MRI technologists must balance the need for higher resolution and image quality against the duration of the scan, ensuring that patients are not subjected to unnecessarily long examination periods. While other factors like signal-to-noise ratio (SNR) and resolution can be influenced by various imaging parameters, the direct relationship between the number of frequency encoding steps and scan time is a key aspect of MRI physics.