Nerves of Steel: a Low-Cost Method for 3D Printing the Cranial Nerves

Abstract

Steady-state free precession (SSFP) magnetic resonance imaging (MRI) can demonstrate details down to the cranial nerve (CN) level. High-resolution three-dimensional (3D) visualization can now quickly be performed at the workstation. However, we are still limited by visualization on flat screens. The emerging technologies in rapid prototyping or 3D printing overcome this limitation. It comprises a variety of automated manufacturing techniques, which use virtual 3D data sets to fabricate solid forms in a layer-by-layer technique. The complex neuroanatomy of the CNs may be better understood and depicted by the use of highly customizable advanced 3D printed models. In this technical note, after manually perfecting the segmentation of each CN and brain stem on each SSFP-MRI image, initial 3D reconstruction was performed. The bony skull base was also reconstructed from computed tomography (CT) data. Autodesk 3D Studio Max, available through freeware student/educator license, was used to three-dimensionally trace the 3D reconstructed CNs in order to create smooth graphically designed CNs and to assure proper fitting of the CNs into their respective neural foramina and fissures. This model was then 3D printed with polyamide through a commercial online service. Two different methods are discussed for the key segmentation and 3D reconstruction steps, by either using professional commercial software, i.e., Materialise Mimics, or utilizing a combination of the widely available software Adobe Photoshop, as well as a freeware software, OsiriX Lite.

3D printed bone models in oral and cranio-maxillofacial surgery: a systematic review

“…Many free or open source software are available, like ITK-Snap®, Slicer® or InVesalius® [31,35,39,40,60,79]. OsiriX® possesses a free version (demo) that allows to export STL renderings [12,46,47,52,63].…”

Neuroanatomy, the Achille’s Heel of Medical Students. A Systematic Analysis of Educational Strategies for the Teaching of Neuroanatomy

“…Although some limitations mainly related to color (one color), this new tool appears promising. Only a limited number of papers on the use of this technique for teaching the neuroanatomy has been published (Javan R et al, 2017).…”

“…A modern technique of 3D printing system has recently been introduced into anatomy curriculum: 3D printing models can be excellent educational tools, more robust and less toxic than fixed tissue (McMenamin et al, 2014, Lim et al, 2016, Vaccarezza and Papa, 2014, Natfulin JS et al, 2015. Cross-sectional imaging is the starting point from which are developed 3D reconstructions, subsequently used for 3D printing (Javan R et al, 2017;Karakas AB et al, 2018). Applications range from education and training, to assistance in daily surgical practice (Baskaran V et al, 2016) (e.g.…”

Is Cadaveric Dissection The “Gold Standard” For Neuroanatomy Education?

“…However, according to a recent meta-analysis by Wilson et al (2019), it would be reasonable if modern, computer-based technologies were also implemented in anatomy pedagogy. Sotgiu et al (2020) argued that three-dimensional (3D) printing is a technology which could provide promising outcomes in neuroanatomy education and cited the study by Javan et al (2017) to show that this method has been applied for neuroanatomy teaching purposes. However, Javan et al 2017manufactured 3D printed cranial nerves and highlighted their realism, without assessing their educational value.…”

“…However, Javan et al 2017manufactured 3D printed cranial nerves and highlighted their realism, without assessing their educational value. Although Javan et al (2017) did not evaluate 3D printing as a teaching tool, the review article by Baskaran et al (2016) highlighted the educational potential of 3D printing concerning anatomy and especially neuroanatomy. Moreover, Baskaran et al (2016) stated that the ability of 3D printing technology to accurately illustrate neuroanatomy could essentially improve neurosurgical training.…”