How can one decrease the thickness of an MRI slice?

To decrease the thickness of an MRI slice, applying a steeper gradient or narrower RF bandwidth is effective due to the principles of MRI slice selection. When a steeper gradient is applied, it creates a more rapid change in the magnetic field over a shorter distance. This allows for a better definition of the slice, resulting in thinner slices.

Furthermore, utilizing a narrower RF bandwidth further refines the selection of the frequencies that resonate, which also contributes to the precision of slice thickness. A narrow bandwidth confines the excitation to a smaller range of frequencies, effectively reducing the slice thickness by minimizing the volume of tissue being excited.

In contrast, employing a lower magnetic field strength generally leads to poorer signal-to-noise ratio and reduced resolution, which does not facilitate thinner slices. A narrower wavelength RF pulse would not inherently reduce slice thickness but would be more about the duration of the excitation and its implications on signal behavior. Using multiple RF pulses can help in increasing the signal strength or achieving different contrast mechanisms but does not directly influence the thickness of the slices.