An investigation into the effect of changing the computed tomography slice reconstruction interval on the spatial replication accuracy of three-dimensional printed anatomical models constructed by fused deposition modelling.

Introduction: Three-dimensional (3D) printed models can be constructed utilising computed tomography (CT) data. This project aimed to determine the effect of changing the slice reconstruction interval (SRI) on the spatial replication accuracy of 3D-printed anatomical models constructed by fused deposition modelling (FDM).
Methods: Three bovine vertebrae and an imaging phantom were imaged using a CT scanner. The Queensland State Government's Animal Care and Protection Act 2001 did not apply as no animals were harmed to carry out scientific activity. The data were reconstructed into SRIs of 0.1, 0.3, 0.5 and 1 mm and processed by software before 3D printing. Specimens and printed models were measured with calipers to calculate mean absolute error prior to statistical analysis.
Results: Mean absolute error from the original models for the 0.1, 0.3, 0.5 and 1 mm 3D-printed models was 0.592 ± 0.396 mm, 0.598 ± 0.479 mm, 0.712 ± 0.498 mm and 0.933 ± 0.457 mm, respectively. Paired t-tests (P < 0.05) indicated a statistically significant difference between all original specimens and corresponding 3D-printed models except the 0.1 mm vertebrae 2 (P = 0.061), 0.3 mm phantom 1 (P = 0.209) and 0.3 mm vertebrae 2 (P = 0.097).
Conclusion: This study demonstrated that changing the SRI influences the spatial replication accuracy of 3D-printed models constructed by FDM. Matching the SRI to the primary spatial resolution limiting factor of acquisition slice width or printer capabilities optimises replication accuracy.
(© 2020 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.)