27 - Leveraging in Situ Microct to Visualize Human Neural Anatomy

Poster Board Number: 27
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Co-authors:

Constantinos Tsiptsis - Biomedical Engineering - Case Western Reserve University School of Engineering; Jichu Zhang - Biomedical Engineering - Case Western Reserve University School of Engineering; Justin Chin - Biomedical Engineering - Case Western Reserve University School of Engineering; Leina Lunasco - Anatomy - Case Western Reserve University School of Medicine; Brandon Brunsman - Anatomy - Case Western Reserve University School of Medicine; Zeyna Samba - Anatomy - Case Western Reserve University School of Medicine; Sophie Scherer - Anatomy - Case Western Reserve University School of Medicine; Marissa Brigger - Anatomy - Case Western Reserve University School of Medicine; Katharine Workman - Anatomy - Case Western Reserve University School of Medicine; Sara Bokhari - Case Western Reserve University School of Medicine; Nicholas Ogrinc - Anatomy - Case Western Reserve University School of Medicine; Aniruddha Upadhye - Biomedical Engineering - Case Western Reserve University School of Engineering; Noa Nuzov - Biomedical Engineering - Case Western Reserve University School of Engineering; Anandakumar Shunmugavel - Biomedical Engineering - Case Western Reserve University School of Engineering; Nicole Pelot - Biomedical Engineering - Duke University; Andrew Shoffstall - Biomedical Engineering - Case Western Reserve University School of Engineering; Andrew Crofton - Anatomy - Case Western Reserve University School of Medicine

Abstract Body : Introduction:

MicroCT is the only method capable of producing 3D images of peripheral nerves and structures of the brain at true micrometer resolution. Additionally, the non-destructive nature of microCT retains true anatomic relationships while enabling augmentive downstream histologic imaging. The goal of the present study is to elucidate complex 3-dimensional relationships of central and peripheral nervous system structures over long distances that are not capable of being evaluated using gross or micro dissection or histologic techniques.



Methods:

Bilateral vagus nerves (n=24 nerves) with surrounding lower cranial nerves in the region distal (0-50 mm) to the jugular foramen, 6 en bloc carotid bifurcations with preserved in situ position and composition of the intercarotid plexus (IP), and 3 pituitary glands en bloc within the sella turcica were removed from 18 human cadavers. Specimens were stained using phosphotungstic acid and imaged via microCT (Scanco Medical μCT 100) with scanning parameters varied to optimize image quality.



Results:

High-resolution microCT images of the vagus nerve reveal multiple communications between the vagus, sympathetic trunk, glossopharyngeal, accessory and hypoglossal nerves. Shared epineurium is common between these lower cranial nerves and the sympathetic trunk in the rostral neck. The IP received contributions from the sympathetic trunk, vagus, and glossopharyngeal nerve. Tracing fibers from the IP back to their origin revealed that the carotid sinus nerve fibers traveled to the carotid body, but not the carotid sinus whereas the sympathetic trunk fibers innervated the carotid sinus, but not the carotid body. The vagus nerve contributed fibers to the carotid sinus, but resolution was insufficient to fully trace the distal vagal fibers through the entire IP. MicroCT of the pituitary confirmed the presence and relationships of the adenoneurohypophyseal septum, a structure only recently described via 2D histology.



Conclusions:

MicroCT provides information that cannot be obtained through traditional anatomic techniques while still maintaining specimen viability with downstream methods.



Significance/Implications:

Our work illustrates the potential of microCT imaging as a tool for redefining anatomic paradigms. Additionally, microCT yields anatomic data that may advance peripheral nerve and CNS interventions.