What effect does reducing receiver bandwidth have on SNR?

• A. Increases SNR
• B. Decreases SNR
• C. No significant effect
• D. Increases imaging time

Answer: (A)

Reducing the receiver bandwidth in MRI increases the signal-to-noise ratio (SNR). This occurs because a narrower bandwidth allows for a more focused collection of signals from the desired slice of tissue while simultaneously reducing the amount of noise picked up from other frequencies.

When the bandwidth is decreased, the system is more selective, effectively filtering out a greater amount of the random noise that can interfere with the desired signal. This selective filtering results in a stronger representation of the actual magnetic resonance signal relative to the noise, thereby enhancing the SNR.

In the context of imaging, while narrowing the bandwidth can improve SNR, it may also lead to other considerations such as increased imaging time or potential aliasing effects in certain situations. However, the primary effect of reducing receiver bandwidth directly correlates with an improvement in SNR, making it a crucial factor to consider when optimizing MRI scans for better image quality.