Three-Dimensional Surface Imaging and Printing in Anatomic Pathology

Abstract

Three-dimensional (3D) imaging is increasingly being incorporated into a variety of medical specialties: surgery and radiology being but two prominent examples. Image-intensive disciplines, such as anatomic pathology (AP), represent excellent potential candidates for further exploration of this innovative technology. Multiple potential use cases exist within AP, involving patient care, education, and research. These use cases broadly include direct utilization of the 3D digital assets for viewing on a 2D screen, populating 3D extended reality platforms (virtual reality, augmented reality, and mixed reality) as well as generation of 3D printed photorealistic specimen models. Herein, these use cases are explored with specific regard to our experiences and yet unrealized potential. Future directions and considerations are also discussed.

Keywords: Augmented reality; photogrammetry; printing; scanning; virtual reality.

Figure 1

Sketches as medical illustrations. Dorothy Reed documented the atypical cells present in Hodgkin lymphoma via hand-drawn sketches (a, reproduced with permissions),[3] which were later compared to the near contemporaneous drawings by Carl Sternberg (b, public domain).[4] The striking similarities between the two observations resulted in moniker of the Reed–Sternberg cell, still used today

Figure 2

Evolution of medical documentation via the photomicrograph. One of the first applications of photography was that of the photomicrograph, as illustrated in Alfred Donne's Atlas du Cours de Microscopie, and entitled “Epidermal cells of normal vaginal mucosa” (translated) in 1845 (a, public domain).[6] Today, photomicrographs are still utilized to document and convey vital concepts in anatomic pathology (b, ThinPrep with Papanicolaou stain, ×600 original magnification)

Figure 3

Equipment utilized in three-dimensional image acquisition. A handheld device (Space Spider, Artec 3D [Santa Clara, CA, USA]) with onboard blue and white light-emitting diodes (LEDs) was utilized to obtain specimen geometry (shape) and texture (color and surface pattern) data (a). Innovations such as mounting of the acquisition device on a tripod, utilization of a turntable with a nonreflective, black surface, and the use of color-coded locator pins increased both scan quality and ease of postscan processing (b)

Figure 4

Image processing progression. (a) Point cloud. (b) Three-dimensional mesh (simple geometry). (c) Three-dimensional mesh (complex, smoothed, geometry). (d) Texture-mapped three-dimensional image

Figure 5

Specimen and evolution of material jetting three-dimensional printed models. (a) Original specimen. (b) Early three-dimensional photorealistic printed model in grayscale. (c) Contemporary three-dimensional photorealistic model printed in full color

Figure 6

Patient–pathologist meeting to review a three-dimensional model of lung explant. Three-dimensional models have enhanced and facilitated patient–pathologist relationships, as demonstrated by regular requests to review explanted organs by our transplant patients. These models allow for safe handling of otherwise biohazardous specimens, and augment patient understanding of his/her disease process

Figure 7

Three-dimensional printed models used in education. Integration of three-dimensional models into the classroom has resulted in improved safety and appreciation of anatomic relationships. Hazards requisite to tissue handing, such as the handling of formalin and biologic materials, had previously been circumvented at our institution by suspending specimens in clear plastic boxes filled with formalin (as seen on the table in the image). However, this solution was suboptimal, as it limits tactile specimen interaction and therefore appreciation of important anatomic relationship. Utilization of photorealistic three-dimensional models obviates the need for these accommodations, allowing for another step forward in medical education

Figure 8

Specimen and three-dimensional printed models. Scanning of the original specimens (a and c) can lead to high-quality, photorealistic three-dimensional models (b and d) that can be utilized, for example, in the classroom with respect to (b) congenital heart disease, and (d) in forensic proceedings in the case of a fracture of the superior horn of the thyroid cartilage during manual strangulation (arrow)