Slice Thickness

Slice thickness is a user controllable parameter in MRI that must be chosen for every acquisition. A 'slice' in MRI is a planar region of excited tissue, from which signal is recorded and images can be reconstructed. Images are viewed at the scanner, and appear to be perfectly thin 2D pixels cut through anatomy on the monitor, but really represent the summed signals of 'chunks' of tissue called voxels that we can view from different angles. It's a bit unintuitive, but is important to understand; slice thickness has major impacts on both Signal to Noise Ratio and Volume Averaging Artifact.