Multi-delay 2D interslice saturation MRI for non-invasive flow mapping of CSF in optic nerve subarachnoid space

Motivation: Normal-tension glaucoma (NTG) is related to reduced CSF flow in the optic nerve, but quantitative methods are limited. This study aimed to quantify CSF flow velocity in human optic nerve subarachnoid space (ONSAS). Goal(s): Develop a non-invasive MRI method, multi-delay IR-ALADDIN, to quantify CSF flow velocity in human ONSAS, aiding NTG research. Approach: Using multi-delay IR-ALADDIN MRI, simulations, phantoms, and human studies were conducted to measure slow ONSAS CSF flow. Results: The measured human ONSAS CSF flow was 0.7-1.2 mm/s, aligning with computational predictions. Impact: This study introduces a non-invasive MRI technique to measure CSF flow in the ONSAS for the first time, offering potential for early NTG diagnosis. Its compatibility with clinical settings could make it a safer, more accessible alternative to invasive methods.