Advanced imaging and digitization of preserved heart specimens using virtual reality - A primer

Introduction: Preserved congenital heart specimens are an important component of training professionals working with children and adults with congenital heart disease. They are curated in few institutions worldwide and not freely accessible. This was a proof-of-concept project to explore the use of advanced cardiac imaging modalities (computed tomography [CT] and magnetic resonance imaging [MRI]) and virtual reality (VR) simulation to assess the feasibility and identify the best method of imaging curated cardiac pathology specimens. Methods: Seven specimens in glass jars with formalin, with varied anatomic lesions, from a curated collection were imaged using MRI and high-dose CT to compare the fidelity of models created via each modality. Three-dimensional (3D) models were created and loaded into a VR headset and viewed in virtual space. Two independent physicians performed a 'virtual dissection' and scored the resultant models. Results: The highest fidelity and tissue characterization of more delicate structures was achieved with T2 spoiled gradient-echo sequences on MRI (median score of 4 out of 5). CT (median score of 3), while excellent for external anatomy, lost some fidelity with delicate internal anatomy, even at high-radiation doses. No specimens were damaged. Conclusions: We believe that in vitro heart specimens can be easily scanned with high fidelity at a relatively low cost, without causing damage, using high-dose CT and MRI. The ability to 'walk through' different chambers of the heart makes the understanding of anatomy easy and intuitive. VR and 3D printing are technologies that could be easily adapted to digitize preserved heart specimens, making it globally accessible for teaching and training purposes.