Full color 3D printing of anatomical models

From 2D slices to a 3D model: Training students in digital microanatomy analysis techniques through a 3D printed neuron project

The reconstruction of two-dimensional (2D) slices to three-dimensional (3D) digital anatomical models requires technical skills and software that are becoming increasingly important to the modern anatomist, but these skills are rarely taught in undergraduate science classrooms. Furthermore, learning opportunities that allow students to simultaneously explore anatomy in both 2D and 3D space are increasingly valuable. This report describes a novel learning activity that trains students to digitally trace a serially imaged neuron from a confocal stack and to model that neuron in 3D space for 3D printing. By engaging students in the production of a 3D digital model, this learning activity is designed to provide students a novel way to enhance their understanding of the content, including didactic knowledge of neuron morphology, technical research skills in image analysis, and career exploration of neuroanatomy research. Moreover, students engage with microanatomy in a way that starts in 2D but results in a 3D object they can see, touch, and keep. This discursive article presents the learning activity, including videos, instructional guides, and learning objectives designed to engage students on all six levels of Bloom's Taxonomy. Furthermore, this work is a proof of principle modeling workflow that is approachable, inexpensive, achievable, and adaptable to cell types in other organ systems. This work is designed to motivate the expansion of 3D printing technology into microanatomy and neuroanatomy education.

Are 3D-printed anatomical models of the ear effective for teaching anatomy? A comparative pilot study versus cadaveric models

PURPOSE

Despite the combination of chalkboard lectures and cadaveric models, the ear remains a complex anatomical structure that is difficult for medical students to grasp. The aim of this study was to evaluate the contribution of a 3D-printed ear model for educating undergraduate medical students by comparing it with a conventional cadaveric model.

METHODS

Models of the ear comprising the outer ear, tympanic membrane, ossicles and inner ear were modeled and then 3D-printed at 6:1 and 10:1 scales based on cadaveric dissection and CT, cone-beam CT and micro/nano CT scans. Cadaveric models included two partially dissected dry temporal bones and ossicles. Twenty-four 3rd year medical students were given separate access to cadaveric models (n = 12) or 3D-printed models (n = 12). A pre-test and two post-tests were carried out to assess knowledge (n = 24). A satisfaction questionnaire focusing solely on the 3D-printed model, comprising 17 items assessed on a 5-point Likert scale, was completed by all study participants. A 5-point Likert scale questionnaire comprising four items (realism, color, quality and satisfaction with the 3D-printed ear model) was given to three expert anatomy Professors.

RESULTS

The test scores on the first post-test were higher for the students who had used the 3D-printed models (p < 0.05). Overall satisfaction among the students and the experts was very high, averaging 4.7 on a 5-point Likert-type satisfaction scale.

CONCLUSION

This study highlights the overall pedagogical value of a 3D-printed model for learning ear anatomy.

Clinical application of instant 3D printed cast versus polymer orthosis in the treatment of colles fracture: a randomized controlled trial

BACKGROUND

The shortcomings of plaster in water resistance, air permeability, skin comfort, fixed stability and weight of wearing are still to be solved. 3D printed cast can overcome the above shortcomings. At present, there is a relative lack of data on the clinical application of 3D printed cast, probably due to its complexity, relatively long operating time, and high price. We aimed to compare and evaluate the short-term effectiveness, safety and advantages of 3D printed wrist cast versus polymer orthosis in the treatment of Colles fracture.

METHODS

Forty patients with Colles fracture in our hospital from June to December 2022 were selected and divided into an observation group (20 patients, treated with instant 3D printed cast) and a control group (20 cases, treated with polymer orthosis). Both groups treated with manual reduction and external fixation. The visual analogue scale (VAS), immobilization effectiveness and satisfaction scores, Disability of the Arm, Shoulder and Hand (DASH) score, complications and imaging data were collected and compared before immobilization and at 2, 6 and 12 weeks after the fracture.

RESULTS

VAS at 2 weeks after the fracture was significantly lower in the observation group than in the control group ( P < 0.05). The immobilization effectiveness and satisfaction scores at 6 weeks after the fracture were significantly higher in the observation group than in the control group (all P < 0.05). The DASH scores at 2 and 6 weeks after the fracture were significantly lower in the observation group than in the control group (all P < 0.05). There wasn't rupture of the printed cast or orthosis in both groups. There were 2 cases of skin irritation in the control group, and no skin irritation occurred in the observation group. The palmar tilt angle and ulnar inclination angle at 2 weeks and 12 weeks after the fracture were significantly higher in the observation group than in the control group (all P < 0.05).

CONCLUSIONS

Both instant 3D printed cast and polymer orthosis are effective in the treatment of Colles fracture. But instant 3D printed cast is better than polymer orthosis in areas of good clinical and imaging performance, and high patient satisfaction and comfort.

3D printing as a pedagogical tool for teaching normal human anatomy: a systematic review

BACKGROUND

Three-dimensional-printed anatomical models (3DPAMs) appear to be a relevant tool due to their educational value and their feasibility. The objectives of this review were to describe and analyse the methods utilised for creating 3DPAMs used in teaching human anatomy and for evaluating its pedagogical contribution.

METHODS

An electronic search was conducted on PubMed using the following terms: education, school, learning, teaching, learn, teach, educational, three-dimensional, 3D, 3-dimensional, printing, printed, print, anatomy, anatomical, anatomically, and anatomic. Data retrieved included study characteristics, model design, morphological evaluation, educational performance, advantages, and disadvantages.

RESULTS

Of the 68 articles selected, the cephalic region was the most studied (33 articles); 51 articles mentioned bone printing. In 47 articles, the 3DPAM was designed from CT scans. Five printing processes were listed. Plastic and its derivatives were used in 48 studies. The cost per design ranged from 1.25 USD to 2800 USD. Thirty-seven studies compared 3DPAM to a reference model. Thirty-three articles investigated educational performance. The main advantages were visual and haptic qualities, effectiveness for teaching, reproducibility, customizability and manipulability, time savings, integration of functional anatomy, better mental rotation ability, knowledge retention, and educator/student satisfaction. The main disadvantages were related to the design: consistency, lack of detail or transparency, overly bright colours, long printing time, and high cost.

CONCLUSION

This systematic review demonstrates that 3DPAMs are feasible at a low cost and effective for teaching anatomy. More realistic models require access to more expensive 3D printing technologies and substantially longer design time, which would greatly increase the overall cost. Choosing an appropriate image acquisition modality is key. From a pedagogical viewpoint, 3DPAMs are effective tools for teaching anatomy, positively impacting the learning outcomes and satisfaction level. The pedagogical effectiveness of 3DPAMs seems to be best when they reproduce complex anatomical areas, and they are used by students early in their medical studies.

Effects of the individual three-dimensional printed craniofacial bones with a quick response code on the skull spatial knowledge of undergraduate medical students

Understanding the three-dimensional (3D) structure of the human skull is imperative for medical courses. However, medical students are overwhelmed by the spatial complexity of the skull. Separated polyvinyl chloride (PVC) bone models have advantages as learning tools, but they are fragile and expensive. This study aimed to reconstruct 3D-printed skull bone models (3D-PSBs) using polylactic acid (PLA) with anatomical characteristics for spatial recognition of the skull. Student responses to 3D-PSB application were investigated through a questionnaire and tests to understand the requirement of these models as a learning tool. The students were randomly divided into 3D-PSB (n = 63) and skull (n = 67) groups to analyze pre- and post-test scores. Their knowledge was improved, with the gain scores of the 3D-PSB group (50.0 ± 3.0) higher than that of the skull group (37.3 ± 5.2). Most students agreed that using 3D-PSBs with quick response codes could improve immediate feedback on teaching (88%; 4.41 ± 0.75), while 85.9% of the students agreed that individual 3D-PSBs clarified the structures hidden within the skull (4.41 ± 0.75). The ball drop test revealed that the mechanical strength of the cement/PLA model was significantly greater than that of the cement or PLA model. The prices of the PVC, cement, and cement/PLA models were 234, 1.9, and 10 times higher than that of the 3D-PSB model, respectively. These findings imply that low-cost 3D-PSB models could revolutionize skull anatomical education by incorporating digital technologies like the QR system into the anatomical teaching repertoire.

Application of additional three-dimensional materials for education in pediatric anatomy

We conducted this study to investigate the effects of additional education using 3D visualization (3DV) and 3D printing (3DP) after applying 2D images for anatomical education in normal pediatric structures and congenital anomalies. For the production of 3DV and 3DP of the anatomical structures, computed tomography (CT) images of the four topics (the normal upper/lower abdomen, choledochal cyst, and imperforate anus) were used. Anatomical self-education and tests were administered to a total of 15 third-year medical students with these modules. Following the tests, surveys were conducted in order to evaluate satisfaction from students. In all four topics, there were significant increases in the test results with additional education with 3DV after initial self-study with CT (P < 0.05). The difference in scores was highest for the imperforate anus when 3DV supplemented the self-education. In the survey on the teaching modules, the overall satisfaction scores for 3DV and 3DP were 4.3 and 4.0 out of 5, respectively. When 3DV was added to pediatric abdominal anatomical education, we found an enhancement in understanding of normal structures and congenital anomalies. We can expect the application of 3D materials to become more widely used in anatomical education in various fields.

Application of 3D-printed pulmonary segment specimens in experimental teaching of sectional anatomy

BACKGROUND

Lung cross-section is one of the emphases and challenges in sectional anatomy. Identification of the complex arrangement of intrapulmonary tubes such as bronchi, arteries, and veins in the lungs requires the spatial imagination of students. Three-dimensional (3D) printing has become increasingly used in anatomy education. This study aimed to analyze the effectiveness of 3D-printed specimens used for the experimental teaching of sectional anatomy.

METHODS

A digital thoracic dataset was obtained and input into a 3D printer to print multicolor specimens of the pulmonary segment after software processing. As research subjects, 119 undergraduate students majoring in medical imaging from classes 5-8 in the second-year were chosen. In the lung cross-section experiment course, 59 students utilized 3D printed specimens in conjunction with traditional instruction as the study group, while 60 students received traditional teaching as the control group. Preclass and postclass tests, course grading, and questionnaire surveys were used to assess instructional efficacy.

RESULTS

We obtained a set of pulmonary segment specimens for teaching. The students in the study group scored better in the postclass test than those in the control group (P < 0.05), and the students in the study group scored higher in satisfaction with the teaching content and spatial thinking for sectional anatomy than those in the control group (P < 0.05). The course grades and excellence rates in the study group exceeded those in the control group (P < 0.05).

CONCLUSION

The application of high-precision multicolor 3D-printed specimens of lung segments in experimental teaching of sectional anatomy can improve teaching effectiveness and is worth adopting and promoting in sectional anatomy courses.

Application of 3D printing technology for pre-operative evaluation, education and informed consent in pediatric retroperitoneal tumors

To investigate usefulness of 3D printing for preoperative evaluations, student and resident education, and communication with parents or guardians of patients with pediatric retroperitoneal tumors. Ten patients planning retroperitoneal tumor resection between March and November 2019 were included. Preoperative computed tomography (CT) images were used for 3D reconstruction and printing. Surveyed items were understanding of preoperative lesions with 3 different modules (CT, 3D reconstruction, and 3D printing) by students, residents, and specialists; satisfaction of specialists; and comprehension by guardians after preoperative explanations with each module. The median age at operation was 4.2 years (range, 1.8-18.1), and 8 patients were diagnosed with neuroblastoma. The 3D printing was the most understandable module for all groups (for students, residents, and specialists, P = 0.002, 0.027, 0.013, respectively). No significant intraoperative adverse events or immediate postoperative complications occurred. All specialists stated that 3D printing enhanced their understanding of cases. Guardians answered that 3D printing were the easiest to comprehend among the 3 modules (P = 0.007). Use of 3D printing in treatment of pediatric patients with retroperitoneal tumors was useful for preoperative planning, education, and parental explaining with obtaining informed consents.

Pigment Penetration Characterization of Colored Boundaries in Powder-Based Color 3D Printing

Color 3D printing has widely affected our daily lives; therefore, its precise control is essential for aesthetics and performance. In this study, four unique test plates were printed using powder-based full-color 3D printing as an example; moreover, the corresponding pigment-penetration depth, chromaticity value and image-based metrics were measured to investigate the lateral pigment penetration characteristics and relative surface-color reproduction of each color patch, and to perform an objective analysis with specific microscopic images. The results show that the lateral pigment-penetration depth correlates with the number of printed layers on the designed 3D test plates, and the qualitative analysis of microscopic images can explain the change in chromaticity well. Meanwhile, there is an obvious linear correlation between the mean structural similarity, color-image difference and color difference for current color samples. Thus, our proposed approach has a good practicality for powder-based color 3D printing, and can provide new insight into predicting the color-presentation efficiency of color 3D-printed substrates by the abovementioned objective metrics.