Feasibility of single-shot multi-slice DENSE MRI at 7 T for strain tensor imaging in a paediatric population.

Many children who have been treated for a posterior-fossa tumour experience neurocognitive problems after treatment with surgery, radiotherapy and/or chemotherapy, which significantly impact their quality of life. Knowledge about these underlying mechanisms is limited at this point. The displacement encoding with stimulated echoes (DENSE) sequence magnetic resonance imaging (MRI) at 7 T can be used to measure brain tissue pulsations, and provide information on both the blood vessels and microstructure simultaneously, which are potentially relevant parameters to assess these underlying mechanisms. A single-shot multi-slice DENSE sequence was used to obtain brain motion maps from which strain maps could be derived on a voxel-wise level. The robustness of this MRI sequence was studied using the root mean square displacement that was obtained during the registration in the analysis of the DENSE series. Although the paediatric participants exhibited noticeable head movement during the MR acquisition, good-quality strain maps were still obtained, displaying expected patterns similar to those seen in adults.