3T PROPELLER diffusion tensor fiber tractography: a feasibility study for cranial nerve fiber tracking

The aim of this study was to evaluate the usefulness of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER)-based diffusion tensor fiber tractography (DTT) at 3T to visualize infratentorial small fiber structures that cannot be visualized adequately using a conventional single shot echo planar imaging (ssEPI)-based pulse sequence.Four healthy male volunteers were examined in this study. Diffusion tensor images were acquired on a 3T clinical magnetic resonance scanner using PROPELLER and echo planar imaging sequences in six motion-probing gradient orientations. Fiber tracking results for the trigeminal and auditory nerves were compared quantitatively.The trigeminal nerve tract was successfully reconstructed using both acquisition methods (100%). Among these reconstructed tracts, 62.5% of the tracts on PROPELLER-DTT and 25% on ssEPI-DTT were followed to branches beyond the trigeminal ganglion. The reconstructed auditory nerve tract could be identified on PROPELER-DTT (62.5%), whereas no tract or only a short tract was obtained on ssEPI-DTT (37.5%).3T PROPELLER-DTT is useful for visualizing infratentorial small neurofiber structures.