Laura Mancini1,2, Faiza Javad2, Jason D. Warren3, John S. Thornton1,2, Xavier Golay1,2, Tarek Yousry1,2, Caroline Micallef1,2
1Lysholm Dept of Neuroradiology, National Hospital for Neurology & Neurosurgery, UCLH NHS Foundation Trust, London, WC1N 3BG, United Kingdom; 2Academic Neuroradiological Unit, Dept Brain Repair & Rehabilitation, UCL Institute of Neurology, London, WC1N 3BG, United Kingdom; 3Dementia Research Centre, UCL Institute of Neurology, London, WC1N 3BG, United Kingdom
This is the first combined DTI/fMRI study to investigate pathways connecting cortical and sub-cortical structures in the auditory system. Auditory pathways connect the inferior collicular nucleus (ICN) and medial geniculate body (MGB) to the auditory cortex. These tracts are particularly difficult to identify because they intersect the optic radiation and numerous other fascicles. 2.3mm isotropic DTI (64 gradient directions, b-value=1400s/mm 2) were analyzed with probabilistic, 2-tensor model tractography. ICN and MGB were identified anatomically, while auditory cortices were identified by fMRI using sparse acquisition and amplitude-modulated iterated-ripple-noise pitch as stimuli. Our results successfully identified sub-cortical auditory projections in 14 healthy subjects.