3D Printing of Preclinical X-ray Computed Tomographic Data Sets

Abstract

Three-dimensional printing allows for the production of highly detailed objects through a process known as additive manufacturing. Traditional, mold-injection methods to create models or parts have several limitations, the most important of which is a difficulty in making highly complex products in a timely, cost-effective manner.1 However, gradual improvements in three-dimensional printing technology have resulted in both high-end and economy instruments that are now available for the facile production of customized models. 2 These printers have the ability to extrude high-resolution objects with enough detail to accurately represent in vivo images generated from a preclinical X-ray CT scanner. With proper data collection, surface rendering, and stereolithographic editing, it is now possible and inexpensive to rapidly produce detailed skeletal and soft tissue structures from X-ray CT data. Even in the early stages of development, the anatomical models produced by three-dimensional printing appeal to both educators and researchers who can utilize the technology to improve visualization proficiency. 3, 4 The real benefits of this method result from the tangible experience a researcher can have with data that cannot be adequately conveyed through a computer screen. The translation of pre-clinical 3D data to a physical object that is an exact copy of the test subject is a powerful tool for visualization and communication, especially for relating imaging research to students, or those in other fields. Here, we provide a detailed method for printing plastic models of bone and organ structures derived from X-ray CT scans utilizing an Albira X-ray CT system in conjunction with PMOD, ImageJ, Meshlab, Netfabb, and ReplicatorG software packages. Video LinkThe video component of this article can be found at https://www.jove.com/video/50250/ Protocol 1. Animals 1. For the results reported below, one male Lobund-Wistar rat of ten months of age was obtained from the Freimann Life Science Center, University of Notre Dame (Notre Dame, Indiana, USA). An ex vivo New Zealand White Rabbit (Male, age = 8 weeks) skull sample, preserved in 10% formalin, was obtained from the laboratory of Prof. Matthew Ravosa, University of Notre Dame. 2. For in vivo imaging, the rat was anesthetized by Isofluorane (2.5% flow rate) with maintenance via a nose-cone system. The animal was positioned prone in the standard rat bed (M2M Imaging Inc., Cleveland, Ohio) supplied with the Albira image station. Limbs were positioned lateral from the torso for a uniform CT acquisition. 3. After image acquisition was completed, the rat was removed from the nose cone and returned to the recovery cage until ambulatory. 4. For scans of the rabbit skull, the specimen was placed in the rat bed in a sealed plastic bag containing formalin. Image Acquisition and Reconstruction1. In Vivo and Ex Vivo Image acquisitions were performed using the Albira CT system (Carestream Molecular Imaging, Woodbridge, CT). The system was set to scan a bed of 180 mm length by perf...

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