Students' learning experiences of three-dimensional printed models and plastinated specimens: a qualitative analysis.

BACKGROUND: Traditional cadaveric dissection is declining whilst plastinated and three-dimensional printed (3DP) models are increasingly popular as substitutes to the conventional anatomy teaching and learning methods. It is unclear about the pros and cons of these new tools and how they impact students' learning experiences of anatomy including humanistic values such as respect, care and empathy.  METHODS: Ninety-six students' views were sought immediately after a randomized cross-over study. Pragmatic design was used to investigate the learning experiences of using plastinated and 3DP models of cardiac (in Phase 1, n = 63) and neck (in Phase 2, n = 33) anatomy. Inductive thematic analysis was conducted based on 278 free text comments (related to strengths, weaknesses, things to improve), and focus group (n = 8) transcriptions in full verbatim about learning anatomy with these tools. RESULTS: Four themes were found: perceived authenticity, basic understanding versus complexity, attitudes towards respect and care, and multimodality and guidance. CONCLUSIONS: Overall, students perceived plastinated specimens as more real and authentic, thus perceived more respect and care than 3DP models; whereas 3DP models were easy to use and prefered for learning basic anatomy.

A validated instrument measuring students' perceptions on plastinated and three-dimensional printed anatomy tools.

Due to the modernization of the medical curriculum and technological advancements, anatomy education has evolved beyond cadaveric dissection alone. Plastination techniques, three-dimensional (3D) modeling, and 3D printing technologies have progressively gained importance. However, there are limited valid and reliable surveys to evaluate students' perceptions of these new anatomy tools. Hence, this study aimed to develop a validated instrument to measure students' learning satisfaction, self-efficacy, humanistic values, and perceived limitations of plastinated and 3D printed models. A 41-item survey (five-point Likert scale, 1 = strongly disagree to 5 = strongly agree) was administered to Year 1 undergraduate medical students following a randomized controlled crossover study that evaluated plastinated and 3D printed cardiac and neck models. Ninety-six responses were received, and a factor analysis was performed with the Kaiser-Meyer-Olkin sampling adequacy of 0.878. The confirmatory factor analysis yielded a 4-factor, 19 items model that had a good fit with the latent constructs of x 2 (147) = 211.568, P < 0.001, root mean square error of approximation = 0.068, root mean square residual = 0.064, comparative fit index = 0.946, and Tucker Lewis index = 0.937. The Cronbach's alpha for the individual factors ranged from 0.74 to 0.95, indicating good internal consistency. This demonstrated a psychometrically valid and reliable instrument to measure students' perceptions toward plastinated and 3D printed models.

Investigating the effectiveness of three-dimensionally printed anatomical models compared with plastinated human specimens in learning cardiac and neck anatomy: A randomized crossover study.

Three-dimensional printing (3DP) technology has been increasingly applied in health profession education. Yet, 3DP anatomical models compared with the plastinated specimens as learning scaffolds are unclear. A randomized-controlled crossover study was used to evaluate the objective outcomes of 3DP models compared with the plastinated specimens through an introductory lecture and team study for learning relatively simple (cardiac) and complex (neck) anatomies. Given the novel multimaterial and multicolored 3DP models are replicas of the plastinated specimens, it is hypothesized that 3DP models have the same educational benefits to plastinated specimens. This study was conducted in two phases in which participants were randomly assigned to 3DP (n = 31) and plastinated cardiac groups (n = 32) in the first phase, whereas same groups (3DP, n = 15; plastinated, n = 18) used switched materials in the second phase for learning neck anatomy. The pretest, educational activities and posttest were conducted for each phase. Miller's framework was used to assess the cognitive outcomes. There was a significant improvement in students' baseline knowledge by 29.7% and 31.3% for Phase 1; 31.7% and 31.3% for Phase 2 plastinated and 3DP models. Posttest scores for cardiac (plastinated, 3DP mean ± SD: 57.0 ± 13.3 and 60.8 ± 13.6, P = 0.27) and neck (70.3 ± 15.6 and 68.3 ± 9.9, P = 0.68) phases showed no significant difference. In addition, no difference observed when cognitive domains compared for both cases. These results reflect that introductory lecture plus either the plastinated or 3DP modes were effective for learning cardiac and neck anatomy.

Development of a three-dimensional printed heart from computed tomography images of a plastinated specimen for learning anatomy.

Learning anatomy is commonly facilitated by use of cadavers, plastic models and more recently three-dimensional printed (3DP) anatomical models as they allow students to physically touch and hold the body segments. However, most existing models are limited to surface features of the specimen, with little opportunity to manipulate the structures. There is much interest in developing better 3DP models suitable for anatomy education. This study aims to determine the feasibility of developing a multi-material 3DP heart model, and to evaluate students' perceptions of the model. Semi-automated segmentation was performed on computed tomgoraphy plastinated heart images to develop its 3D digital heart model. Material jetting was used as part of the 3D printing process so that various colors and textures could be assigned to the individual segments of the model. Morphometric analysis was conducted to quantify the differences between the printed model and the plastinated heart. Medical students' opinions were sought using a 5-point Likert scale. The 3DP full heart was anatomically accurate, pliable and compressible to touch. The major vessels of the heart were color-coded for easy recognition. Morphometric analysis of the printed model was comparable with the plastinated heart. Students were positive about the quality of the model and the majority of them reported that the model was useful for their learning and that they would recommend their use for anatomical education. The successful feasibility study and students' positive views suggest that the development of multi-material 3DP models is promising for medical education.

Can MRI accurately detect pilon articular malreduction? A quantitative comparison between CT and 3T MRI bone models.

BACKGROUND: Pilon fracture reduction is a challenging surgery. Radiographs are commonly used to assess the quality of reduction, but are limited in revealing the remaining bone incongruities. The study aimed to develop a method in quantifying articular malreductions using 3D computed tomography (CT) and magnetic resonance imaging (MRI) models. METHODS: CT and MRI data were acquired using three pairs of human cadaveric ankle specimens. Common tibial pilon fractures were simulated by performing osteotomies to the ankle specimens. Five of the created fractures [three AO type-B (43-B1), and two AO type-C (43-C1) fractures] were then reduced and stabilised using titanium implants, then rescanned. All datasets were reconstructed into CT and MRI models, and were analysed in regards to intra-articular steps and gaps, surface deviations, malrotations and maltranslations of the bone fragments. RESULTS: Initial results reveal that type B fracture CT and MRI models differed by ~0.2 (step), ~0.18 (surface deviations), ~0.56° (rotation) and ~0.4 mm (translation). Type C fracture MRI models showed metal artefacts extending to the articular surface, thus unsuitable for analysis. Type C fracture CT models differed from their CT and MRI contralateral models by ~0.15 (surface deviation), ~1.63° (rotation) and ~0.4 mm (translation). CONCLUSIONS: Type B fracture MRI models were comparable to CT and may potentially be used for the postoperative assessment of articular reduction on a case-to-case basis.

Metal artifacts from titanium and steel screws in CT, 1.5T and 3T MR images of the tibial Pilon: a quantitative assessment in 3D.

Radiographs are commonly used to assess articular reduction of the distal tibia (pilon) fractures postoperatively, but may reveal malreductions inaccurately. While magnetic resonance imaging (MRI) and computed tomography (CT) are potential three-dimensional (3D) alternatives they generate metal-related artifacts. This study aims to quantify the artifact size from orthopaedic screws using CT, 1.5T and 3T MRI data. Three screws were inserted into one intact human cadaver ankle specimen proximal to and along the distal articular surface, then CT, 1.5T and 3T MRI scanned. Four types of screws were investigated: titanium alloy (TA), stainless steel (SS) (Ø =3.5 mm), cannulated TA (CTA) and cannulated SS (CSS) (Ø =4.0 mm, Ø empty core =2.6 mm). 3D artifact models were reconstructed using adaptive thresholding. The artifact size was measured by calculating the perpendicular distance from the central screw axis to the boundary of the artifact in four anatomical directions with respect to the distal tibia. The artifact sizes (in the order of TA, SS, CTA and CSS) from CT were 2.0, 2.6, 1.6 and 2.0 mm; from 1.5T MRI they were 3.7, 10.9, 2.9, and 9 mm; and 3T MRI they were 4.4, 15.3, 3.8, and 11.6 mm respectively. Therefore, CT can be used as long as the screws are at a safe distance of about 2 mm from the articular surface. MRI can be used if the screws are at least 3 mm away from the articular surface except for SS and CSS. Artifacts from steel screws were too large thus obstructed the pilon from being visualised in MRI. Significant differences (P<0.05) were found in the size of artifacts between all imaging modalities, screw types and material types, except 1.5T versus 3T MRI for the SS screws (P=0.063). CTA screws near the joint surface can improve postoperative assessment in CT and MRI. MRI presents a favourable non-ionising alternative when using titanium hardware. Since these factors may influence the quality of postoperative assessment, potential improvements in operative techniques should be considered.