Rapid three-dimensional multicomponent relaxation imaging of the cervical spinal cord.

Currently, little is known about the pathology of myelin in spinal cord disease due to the technical challenges of specifically measuring myelin content noninvasively. Multicomponent relaxometry allows estimation of the myelin water fraction, which is related to myelin content. However, conventional multiple-echo spin-echo-based multicomponent relaxometry techniques require prohibitively long acquisition times, lack spatial coverage, and are sensitive to artifacts common in spinal cord imaging. Multicomponent driven equilibrium single pulse observation of T(1) and T(2) (mcDESPOT) offers a promising alternative to conventional multicomponent relaxometry techniques. The goal of this pilot study was to assess the efficacy of mcDESPOT for obtaining high spatial resolution spinal cord myelin water fraction data covering the entire cervical spinal cord. Myelin water fraction values were found to be highly reproducible between subjects and over time but varied considerably along the length of the cord. Other relaxation characteristics that relate to tissue structure and health were also reliably measured.