A narrow receiver bandwidth causes which of the following effects?

A narrow receiver bandwidth impacts several aspects of MRI, particularly concerning artifact creation and signal-to-noise ratio (SNR). When the bandwidth is narrow, it diminishes the frequency range that can be received for a given imaging sequence. This has a direct effect on susceptibility artifacts, which arise due to variations in magnetic susceptibility between different tissues or between tissue and air. With a narrow bandwidth, there is less frequency dispersion, which can exacerbate these artifacts because they may become more pronounced at the edges of lesions or interfaces where susceptibility differences are most stark.

Additionally, using a narrow receiver bandwidth does tend to reduce SNR, as a wider bandwidth generally allows more noise to be included in the signal processing. However, this particular aspect is less highlighted in the context of the question. The more consequential effect is the increased susceptibility artifact, as these artifacts are directly linked to how the receiver bandwidth interacts with the magnetic field and the properties of the tissues involved.

The implications of using a narrow receiver bandwidth suggest careful consideration in clinical practice, especially in areas where artifacts could obscure important diagnostic information. Therefore, it's essential to understand that while a narrow bandwidth can be applied in certain situations, it is not ideal in the presence of metal or in situations aiming to minimize susceptibility artifacts.