Magnetic Resonance Imaging (MRI) Practice Test

Which parameter adjustments are beneficial for improving SNR in an MR image?

1. Increase TR, Reduce phase matrix, Increase FOV

2. Reduce rBW, Decrease NSA, Increase ETL

3. Decrease TR, Increase pixel size, Increase rBW

4. Increase TR, Reduce phase matrix, Increase FOV, Reduce rBW, Increase NSA, Decrease ETL

The correct answer is: Increase TR, Reduce phase matrix, Increase FOV, Reduce rBW, Increase NSA, Decrease ETL

Improving the signal-to-noise ratio (SNR) in an MRI image is crucial for enhancing image quality and diagnostic accuracy. The most effective adjustments to optimize SNR involve manipulating several imaging parameters in a way that enhances the signal while minimizing noise. Increasing the repetition time (TR) allows more longitudinal relaxation time for protons to recover, which can improve the overall signal. A longer TR contributes to better SNR by increasing the time available for signal acquisition from the tissue being imaged. Reducing the phase matrix reduces the number of phase encodings in the acquired data, which leads to fewer total lines of data collected and thus decreases the noise that may be present in the image. This effectively increases the SNR as fewer noise components are captured in the imaging process. Increasing the field of view (FOV) can also improve SNR because a larger area allows more signals from the imaged area to be captured. This wider area collects more signal and distributes it over a larger pixel size, ultimately enhancing SNR. Reducing the receiver bandwidth (rBW) narrows the frequency range of signals collected and can reduce noise, contributing favorably to SNR. A lower rBW allows for signal averaging, further enhancing the SNR. Increasing the