Asymmetric magnetization transfer ratio of locus coeruleus with sleep disorder: A 7T MRI study

Neuromelanin (NM), mainly found in locus coeruleus (LC), is a well-known biomarker for neurodegenerative diseases such as Parkinson's disease (PD) and can be detected with neuromelanin-sensitive MRI (NM-MRI). However, whether NM content is associated with sleep disorders is largely unclear. We acquired 3D turbo flash MTC images from 20 normal and four dyssomnia adult males in a 7T scanner to examine the relationship between the sleep quality scores and the NM content in LC. Our preliminary results reveal that the magnetization transfer ratio (MTR), an indicator of NM concentration, of bilateral LC is significantly asymmetric in the dyssomnia group, and the mean value of MTR is lower in the left LC and higher in the right LC in dyssomnia group than normal group.