Advances in MRI of glymphatic system dysfunction associated with obstructive sleep apnea and enlarged perivascular spaces.

Obstructive sleep apnea (OSA) is closely associated with an increased risk of cerebral small-vessel disease and cognitive impairment. OSA not only impairs cognitive function but also promotes the occurrence and development of enlarged perivascular spaces (EPVS) by impairing glymphatic system (GS) function. Perivascular spaces (PVS) are an important imaging marker of cerebral small-vessel disease and a morphological indicator of the functional status of the GS. However, the pathogenesis of OSA-related EPVS remains unclear, with GS dysfunction considered to be at its core. Magnetic resonance imaging (MRI) is a key tool for evaluating the association between OSA and EPVS, and emerging MRI techniques have provided imaging evidence to reveal the potential link between OSA-related GS dysfunction and EPVS formation. This article reviews the relationship between OSA severity, sleep structure, and the distribution of EPVS and focuses on the application of structural MRI, voxel-based morphometry, diffusion tensor imaging, diffusion tensor imaging analysis along the perivascular spaces, diffusion kurtosis imaging, dynamic contrast-enhanced MRI, phase-contrast and 4D flow MRI, and blood oxygen level-dependent functional MRI in the study of the relationship between OSA and EPVS.