Background: Different strategies have been used to study fiber tract anatomy of the human brain in vivo and ex vivo. Nevertheless, the ideal method to study white matter anatomy is yet to be determined, since it should integrate information obtained from multiple sources.
Objective: We developed an anatomical method in cadaveric specimens to study the central core of the cerebrum combining the “traditional” white matter dissection with high-resolution 7 Tesla (T) magnetic resonance imaging (MRI) of the same specimen coregistered using a neuronavigation system.
Methods: Ten cerebral hemispheres were prepared using traditional Klingler’s technique. Before dissection, a structural ultra-high magnetic field 7T MRI study was performed on each hemisphere specifically prepared with surface fiducials for neuronavigation. The dissection was then performed from the medial hemispheric surface using the classic white fiber dissection technique. During each step of the dissection, the correlation between the anatomical findings and the 7T MRI was evaluated with the neuronavigation system.
Results: The anatomic study was divided in two stages. The diencephalic stage included epithalamic, thalamic, hypothalamic, and subthalamic components. The limbic stage consisted of extending the dissection to complete the Papez circuit. The detailed information given by the combination of both methods permitted us to identify and validate the position of fibers that may be difficult to appreciate and dissect, i.e. the medial forebrain bundle.
Conclusion: The correlation of high-definition 7T MRI and the white matter dissection technique with neuronavigation significantly improves the understanding of the structural connections in complex areas of the human cerebrum.
From: Anatomic Study of the Central Core of the Cerebrum Correlating 7 Tesla Magnetic Resonance Imaging and Fiber Dissection With the Aid of a Neuronavigation System by Alarcon et al.