Development of a three-dimensional computer model of the equine heart using a polyurethane casting technique and in vivo contrast-enhanced computed tomography.

The research creates an accurate three-dimensional computer model of a horse’s heart. It was achieved using a contrast-enhanced computed tomography, which proved more suitable than cardiac casting made of polyurethane foam.

Objective of the Study

• The research aimed at forming a three-dimensional (3D) model of an equine heart, which would assist in veterinary education and the development of minimally invasive cardiac procedures.

Methodology

• The researchers performed an in situ cardiac casting using polyurethane foam on ten horses euthanized for non-cardiac related reasons. The hearts were then excised and computed tomography (CT) scans taken.
• Furthermore, in five anaesthetized ponies, a standardized CT protocol enhanced with contrast was used to image the entirety of the heart.
• The researchers used dedicated image processing software to create 3D models from both CT scan methods. The generated models were evaluated for relative proportions, level of detail, and ease of segmentation.

Findings

• The generated cards from the polyurethane foam technique showed high detail, but the structures like the pulmonary trunk were disproportionally expanded due to the foam’s compliance.
• By refining and optimizing the contrast-enhanced CT protocol, which included adding a delayed phase for visualizing the cardiac veins, a sufficiently detailed CT scan was achieved. These scans could be used to generate an anatomically accurate 3D model of the pony’s heart.
• However, the pony heart model had to be resized to obtain a model replicating the size of an adult horse’s heart.

Conclusions

• The researchers found that 3D computer models based on contrast-enhanced CT images were superior to models derived from cast hearts for accurately representing the in vivo situation.
• These models are preferred for creating educationally valuable and anatomically correct heart models for education, research, and client communication.
• However, sizing adjustments are required to create an accurate model of an adult horse’s heart, given the limitations of cardiac CT imaging by thoracic size.