Intra- and inter-session reliability of lumbar spinal cord resting-state fMRI

We investigated the intra- and inter-session reliability of functional connectivity indices derived from resting-state fMRI in the lumbar spinal cord. Slicewise and average indices of connectivity for the ventral and dorsal networks were collected across three experiments in healthy participants at 3T. Intra-session reliability was high for back-to-back scans (ICC>0.9), and moderate-to-good when introducing repositioning, surveying and reshimming (COV=3-25%). Repeatability of indices across separate visits was low, although similar grey matter functional networks could be independently observed and showed high spatial overlap using ICA, a data-driven approach. This is the first evaluation of resting-state fMRI reliability in the lumbar cord.