What is the purpose of placing a pre-saturation slab over the aorta during lumbar spine studies?

Placing a pre-saturation slab over the aorta during lumbar spine studies is primarily aimed at reducing pulsation artefact. The aorta is a major vessel that can cause significant motion due to blood flow. When the heart pumps, the aorta expands and contracts, which can introduce undesirable variations in the MRI signals, leading to blurring or distortion in the images of the lumbar spine. By applying a pre-saturation slab, the MRI sequence can nullify the signals coming from the aorta, effectively minimizing the impact of pulsatile motion on the images. This technique enhances the clarity and diagnostic quality of the lumbar spine scans, allowing for more accurate assessment and evaluation of spinal conditions.

Enhancing image resolution involves different techniques, typically related to the MRI parameters such as slice thickness and matrix size, rather than the placement of saturation slabs. Minimizing breathing artefact would require different strategies, such as gating techniques or breath-holding instructions. Eliminating motion artefacts might be addressed through various methods, including patient instructions or the use of faster imaging sequences, rather than solely relying on saturation slabs.