Efficacy of using a 3D printed lumbosacral spine phantom in improving trainee proficiency and confidence in CT-guided spine procedures

Novel Barium-Enhanced 3-Dimensional-Printed Spine Model for Pedicle Screw Training: A Cost-Effective Solution and Educational Validation

BACKGROUND AND OBJECTIVES

Training in pedicle screw placement is crucial for neurosurgery residents, yet access to high-fidelity training models is often limited by cost and availability. This study introduces a novel, cost-effective barium-enhanced 3-dimensional (3D)-printed L4-5 spine model visible under fluoroscopy, aiming to validate its effectiveness as a training tool for novice residents in pedicle screw placement.

METHODS

A barium-enhanced 3D-printed L4-5 spine model was developed to simulate human bone density and provide radiopacity under fluoroscopy. Ten neurosurgery residents with no prior experience in pedicle screw placement participated in a structured training program using this model. Each resident completed three training sessions, placing four pedicle screws per session, totaling 120 screw placements. Surgical duration, screw placement accuracy, and fluoroscopy usage were recorded. Screw placement accuracy was assessed by two independent blinded evaluators using both a visual grading method and the computed tomography-based Gertzbein-Robbins classification.

RESULTS

The analysis demonstrated significant improvement in surgical time across sessions (P < .0001), decreasing from 20:44 ± 4:32 minutes to 13:17 ± 4:04 minutes. The median number of fluoroscopic images decreased from 8.5 (range: 5-18) to 6.0 (range: 5-10), although not statistically significant (P = .312). Visual assessment scores improved, with median breach scores decreasing from 0.25 (0.00-3.00) to 0.00 (0.00-0.25). Similarly, the median Gertzbein-Robins grades improved from 0.50 (0.12-2.88) to 0.12 (0.00-0.62). Visual and computed tomography-based assessments showed excellent correlation (intraclass correlation coefficients = 0.978, 95% CI: 0.953-0.989, P < .001).

CONCLUSION

The barium-enhanced 3D-printed spine model ($1.61/session) provides a highly cost-effective training tool for novice residents, demonstrating significant improvements in surgical efficiency. Although accuracy measures showed promising trends, more extensive studies may be needed to establish definitive improvements in placement precision. The model's radiopacity allows for realistic fluoroscopic imaging, bridging the gap between basic models and more expensive alternatives, which is particularly valuable in resource-limited settings.

Development and validation of a cost-effective three-dimensional-printed cervical spine model for endoscopic posterior cervical foraminotomy training: a prospective educational study from Turkey

STUDY DESIGN

Expanding upon established surgical simulation methods, we developed a fused deposition modeling three-dimensional (3D)-printed model of the C1-T1 vertebra for posterior cervical foraminotomy training that features silicone-based neural elements, polyurethane foam-based ligaments, and polyethylene terephthalate glycol vertebrae.

PURPOSE

This study evaluated the effectiveness of a cost-efficient 3D-printed training model designed to help neurosurgical residents acquire fundamental skills in endoscopic posterior cervical foraminotomy while addressing the technique's challenging learning curve and limited training resources.

OVERVIEW OF LITERATURE

Only a few studies have investigated the efficacy of such a model.

METHODS

Eight neurosurgery residents each with over 2 years of training completed four training sessions on two randomly assigned cervical spine levels using the newly developed 3D-printed model. A simple plumbing endoscope was used for real-time surgical visualization.

RESULTS

Among the 64 completed surgical levels, left-sided procedures showed significantly higher insufficient decompression rates than did right-sided procedures (25.0% vs. 3.6%, p=0.002). However, no significant difference in overall complication rates was observed between sides (p=0.073). Surgical parameters remained consistent across sides, with no significant differences in operative duration. Brunner-Langer analysis revealed substantial improvements in operative duration (mean duration decrease from 21:42±2:15 to 6:33±0:42 minutes, p=0.004) and total complications (mean decrease from 2.1±0.8 to 0.4±0.5, p=0.007) across sessions. Although fluoroscopy timing showed marginal improvement (mean duration decrease from 2:12±1:15 to 0:55±0:23 minutes, p=0.057), the number of fluoroscopic images tended to decrease.

CONCLUSIONS

Our findings suggest that this novel 3D-printed cervical spine model could be a viable, low-cost option for neurosurgical training programs aiming to help residents develop essential endoscopic skills in a controlled setting. Facilitating early proficiency in posterior cervical foraminotomy can serve as a valuable intermediate step before transitioning to cadaveric models and clinical practice.

Design and 3D printing of pelvis phantoms for cementoplasty

BACKGROUND

Percutaneous image-guided cementoplasty is a medical procedure for strengthening bones structurally altered by disease, such as osteolytic metastasis. This procedure involves injecting biocompatible liquid bone cement, through one or more trocars into the damaged bone. Within a few minutes the bone cement hardens and restores the rigidity of the bony structure. The introduction of this technique in the case of large cancellous bones, such as the pelvis, raises some practical issues such as: how to manage the flow of cement with variable viscosity over time and how to inject a large amount of cement under fluoroscopy to effectively restore the patient's ability to bear weight?

PURPOSE

As a means of training for young practitioners to ensure maximal filling of a metastatic bone area, we have designed and manufactured a pelvic phantom capable of replicating cement diffusion in healthy and metastatic bone under fluoroscopic and computed tomography guidance.

METHODS

The preliminary stage of the study consisted of an analysis of various lattice structures, with the objective of reproducing the haptic feedback experienced during the needle insertion and diffusion of cement within the trabecular bone. Cementoplasty tests were conducted by an experienced radiologist under fluoroscopy and CT guidance to evaluate the performance of the lattice structure. The initial analysis provided the groundwork for the design of the phantom pelvis, which was then evaluated against a patient case. The phantom was divided into two distinct components: a disposable section with lattice structure, intended for the injection of cement, and a reusable part representing the pelvic bones. Two additive manufacturing methods were selected for the production of the phantom: Stereolithography (SLA) for the lattice structure and Fused Deposition Modeling (FDM) for the pelvic bones. The disposable component was composed of different lattice structures, selected to best match the anatomic conditions of both healthy and diseased areas visible on the patient images. Subsequently, the performance of the phantom was validated against patient images through a cementoplasty test.

RESULTS

A total of 12 distinct lattice structures were subjected to three tests of cementoplasty. Stochastic lattices with 500 microns beam thickness and densities varying from 15% to 5% demonstrated the most effective replication of the needle haptic feedback, as well as the diffusion of the cement into healthy and osteolytic cancellous bone. These structures were then implanted in the phantom and validated against one patient case.

CONCLUSIONS

A methodology to design and manufacture a phantom dedicated to cementoplasty from patient images is proposed. Initially, a series of lattice structures, exhibiting diverse structure types, thicknesses, and densities, were evaluated to assess their capacity to accurately reproduce the haptic feedback of the needle and the diffusion of cement in the trabecular bone. Subsequent to the outcomes of these investigations, several structures were selected for the development of a phantom capable of accurately replicating a cementoplasty procedure under fluoroscopy and CT guidance. This phantom will enable the training of future practitioners on the procedure of cementoplasty in the pelvis.

Applying a three-dimensional curved lumbar spine model to simulate surgery for training residents in pedicle screw insertion

PURPOSE

The challenges of spinal surgery can be overcome by deeply understanding the anatomical and surgical complexities of the region through the use of model simulators. This study investigates the impact of digitally designed simulators, specifically lumbar spinal models with abnormal curvature, on preoperative planning and their effectiveness as training tools. The study addresses challenges in spine surgery, such as unique deformities, classification issues, and associated abdominal structure abnormalities.

METHODS

Twenty life-sized lumbar spine models exhibiting lateral curvature, intervertebral rotation, asymmetry in spinal segments, and disc abnormalities were 3D printed for 20 trainees to practice pedicle screw placement across five levels. A detailed survey evaluated the residents' views on the anatomical realism of the model and its surgical application, focusing on screw sizes, procedure duration, placement accuracy, materials, and surgical techniques. The study emphasized understanding the anatomical bone structure, identifying lumbar spinal curvature, decision-making, pedicle placement, the development of surgical strategies, and the educational value of the simulator. It rated their understanding on a scale from 1 to 5, where 1 indicates very low understanding and 5 signifies extremely high understanding.

RESULTS

Post-practice surveys revealed that the primary challenge for residents was determining the correct direction for pedicle screw placement, with the model's loss of resistance being perceived as less realistic. Despite this, the simulated environment was found to be beneficial, with realistic procedural steps. Significant differences emerged in residents' perceptions regarding the identification of scoliosis levels (3.5), imitation of bone tissue (4.30), anatomical positioning of the pedicle start (3.55), and preparation for posterior deformity correction (4.7). The model proved to be an effective teaching tool, particularly in enhancing manual skills for pedicle screw placement (4.9), preparation for deformity correction (4.7), explaining surgery to patients and their families (4.8), and potentially reducing surgery time (4.6).

CONCLUSION

The scoliotic model received high ratings for its appropriateness in screw placement, earning a 'very good' evaluation (4.2). Notably, its contribution to learning pedicle screw placement was rated very positively (4.7), highlighting its effectiveness as a valuable training tool. Scoliotic models play a crucial role in helping orthopedists understand patient-specific deformities and enhance preoperative preparation, ultimately contributing to improved surgical outcomes.

SimuVet: a preliminary study of the innovative development of a simulator for epidural anesthesia training in dogs

Epidural anesthesia in dogs is a locoregional anesthesia technique used in veterinary medicine, becoming an important integrated application in the anesthetic protocol to provide safer and more effective analgesia to patients. For this, professionals must adhere to rigorous guidelines and possess technical skills. In this context, in veterinary education, the development of practical clinical skills represents a crucial aspect in the training of these professionals. However, traditional teaching methods have proven insufficient to ensure a consistent level of competence among recent graduates. The introduction of non-animal alternatives for educational purposes has contributed to the development of simulation-based teaching, an innovative and accessible field capable of enhancing pre-clinical proficiency in students and reducing the use of live animals and cadavers. Despite its application in various areas of veterinary education, there are no conclusive results regarding the development of accessible simulators capable of effectively enhancing training in epidural anesthesia in dogs. Therefore, this article represents a pioneering study aimed at sharing a method for creating SimuVet, a realistic simulator for training epidural anesthesia in dogs. The simulator was fully developed by veterinary researchers with limited experience in 3D printing and, after preliminary analysis, demonstrated excellent performance and ultrasonographic anatomy. Future work will focus on the formal validation of this simulator with the aim of improving the teaching and learning process for students and experts in performing epidural anesthesia in companion animals.

Design, Fabrication, and Preliminary Validation of Patient-Specific Spine Section Phantoms for Use in Training Spine Surgeons Outside the Operating Room/Theatre

Pedicle screw fixation (PSF) demands rigorous training to mitigate the risk of severe neurovascular complications arising from screw misplacement. This paper introduces a patient-specific phantom designed for PSF training, extending a portion of the learning process beyond the confines of the surgical room. Six phantoms of the thoracolumbar region were fabricated from radiological datasets, combining 3D printing and casting techniques. The phantoms were employed in three training sessions by a fifth-year resident who performed full training on all six phantoms; he/she placed a total of 57 pedicle screws. Analysis of the learning curve, focusing on time per screw and positioning accuracy, revealed attainment of an asymptotic performance level (around 3 min per screw) after 40 screws. The phantom's efficacy was evaluated by three experts and six residents, each inserting a minimum of four screws. Initial assessments confirmed face, content, and construct validity, affirming the patient-specific phantoms as a valuable training resource. These proposed phantoms exhibit great promise as an essential tool in surgical training as they exhibited a demonstrable learning effect on the PSF technique. This study lays the foundation for further exploration and underscores the potential impact of these patient-specific phantoms on the future of spinal surgical education.

Interventional Spine Course: Improving Fluoroscopic Safety and Procedural Efficacy Among Physical Medicine and Rehabilitation Residents Using a Lecture and Model-Based Curriculum

ABSTRACT

Therapeutic interventional techniques using fluoroscopy are often used in the management of spinal pain. Currently, there are no standardized means of instruction and assessment of fluoroscopic interventional spinal procedures for physiatry trainees. The aim of our study is to evaluate the utility of an interventional spine training course for physical medicine and rehabilitation residents in improving safety and efficacy when performing these procedures. We performed a prospective multiple cohort study analyzing interventional spine knowledge and procedural ability among physical medicine and rehabilitation residents after implementing a training course that used lectures, hands-on training, and video-recorded objective structured clinical examination self-assessments. Of the total of 28 physical medicine and rehabilitation residents over the 2-yr study period, each class saw a statistically significant improvement in mean objective structured clinical examination scores from pre-examination to postexamination ( P < 0.05). Written examination scores also had a statistically significant preimprovement to postimprovement in the postgraduate years 2 and 3 classes. Our study supports the use of an interventional spine course for physical medicine and rehabilitation residents, and by following the existing cohorts and adding more cohorts in the future, we will continue to demonstrate valuable and comprehensive results.

Current applications of 3-dimensional printing in spine surgery

Background

Three-dimensional printing (3D Printing) has emerged as a new technology in the early part of the 21st century, with promising applications in various industries, including the medical field. Spine care is a complex sub-specialty that has shown rapid inculcation of 3D printing. This technology is being used in pre-operative planning, patient education, and simulations, as well as intra-operatively for assistance in the form of patient specific jigs for pedicle screw placement and as implantable material in the form of vertebral body substitutes and patient-specific interbody cages.

Applications

3DP in spine care has broadened the scope of minimally invasive and spine deformity surgeries. It has also enabled the production of patient-specific implants for complex spinal malignancies and infections. The technology has been embraced by various government organizations, including the US-FDA, which has drafted guidelines for the medical use of 3DP.

Drawbacks

Despite these promising advances and results, there still exist some significant drawbacks to the universal application of 3D printing technology. One of the main limitations is the dearth of long-term data describing the advantages and drawbacks in its clinical use. The widespread adoption of 3D models in small-scale healthcare setups is impeded by significant factors such as the high cost associated with their production, the requirement for specialized human resources, and specific instrumentation.

Conclusion

As technological understanding increases, newer applications and innovations in spine care are expected to unravel in the near future. With the expected surge in 3DP applications in spine care, it is imperative for all spine surgeons to possess a rudimentary understanding of this technology. Although there are still limitations to its universal use, 3DP in spine care has shown promising results and has the potential to revolutionize the field of spine surgery.

Development of a Pedicle Screw Fixation Simulation Model for Surgical Training Using a 3-Dimensional Printer

OBJECTIVE

Training surgeons in pedicle screw fixation (PSF) techniques during actual surgery is limited because of patient safety, complications, and surgical efficiency issues. Recent technical developments are leading the world to an era of personalized three-dimensional (3D) printing. This study aimed to evaluate the educational effect of using a 3D-printed spine model to train beginners in PSF techniques to improve screw accuracy and procedure time.

METHODS

Computed tomography (CT) scan data were used in a 3D printer to produce a life-size lumbar spine replica of L1-3 vertebrae. Four residents performed PSF thrice. Each resident performed 18 screw fixations on both sides (6 screws per trial). The time to complete the procedure and pedicle violation was recorded.

RESULTS

The average time for the 3 procedures was 42.1±2.9 minutes, 38.8±3.3 minutes, and 32.1±2.5 minutes, respectively. Furthermore, the average pedicle screw score for the 3 procedures was 13.0±0.8, 14.5±0.6, and 16.0±0.8, respectively. As the trial was repeated, the procedure time decreased and the accuracy of screw fixation tended to be more accurate.

CONCLUSIONS

It was possible to decrease the procedure time and increase accuracy through repeated training using the 3D-printed spine model. By implementing a 3Dprinted spine model based on the patient's actual CT data, surgeons can perform simulation surgery before the actual surgery. Therefore, this technology can be useful in educating residents to improve their surgical skills.

Properties and Implementation of 3-Dimensionally Printed Models in Spine Surgery: A Mixed-Methods Review With Meta-Analysis

OBJECTIVE

Spine surgery addresses a wide range of spinal pathologies. Potential applications of 3-dimensional (3D) printed in spine surgery are broad, encompassing education, planning, and simulation. The objective of this study was to explore how 3D-printed spine models are implemented in spine surgery and their clinical applications.

METHODS

Methods were combined to create a scoping review with meta-analyses. PubMed, EMBASE, the Cochrane Library, and Scopus databases were searched from 2011 to 7 September 2021. Results were screened independently by 2 reviewers. Studies utilizing 3D-printed spine models in spine surgery were included. Articles describing drill guides, implants, or nonoriginal research were excluded. Data were extracted according to reporting guidelines in relation to study information, use of model, 3D printer and printing material, design features of the model, and clinical use/patient-related outcomes. Meta-analyses were performed using random-effects models.

RESULTS

Forty articles were included in the review, 3 of which were included in the meta-analysis. Primary use of the spine models included preoperative planning, education, and simulation. Six printing technologies were utilized. A range of substrates were used to recreate the spine and regional pathology. Models used for preoperative and intraoperative planning showed reductions in key surgical performance indicators. Generally, feedback for the tactility, utility, and education use of models was favorable.

CONCLUSIONS

Replicating realistic spine models for operative planning, education, and training is invaluable in a subspeciality where mistakes can have devastating repercussions. Future study should evaluate the cost-effectiveness and the impact spine models have of spine surgery outcomes.

3D printing in spine care: A review of current applications

3D printing (3DP) has been brought to medical use since the early part of this century- but it has been widely researched on and publicized only in the last few years. Amongst patients with spinal disorders, 3DP has been utilized in various facets of patient care. These include pre-operative aspects - such as patient education, resident training, pre-operative planning and simulations, intra-operative assistance in the form of customized jigs for pedicle screw insertion, patient specific interbody cages and vertebral body substitutes in complex malignancies and spinal infections. It has also been utilized in deformity surgeries and has opened new avenues in minimally invasive spine care. Guidelines have now been drafted by various organizations including the FDA with a prime focus on quality control measures applicable to this new technology. There has been a recent surge in publications supporting the use of 3DP in spinal disorders, reporting an improvement in various aspects of patient care. As the technology spreads out its wings further, more innovations and applications are expected to unfold in the coming years. Considering the rapid advances that 3DP has made, having a basic understanding of this technology is imperative for all spine surgeons. Despite promising preliminary results, there still exist a few pitfalls of the technology which have hindered the universal application of 3DP. Most importantly, there is a dearth of data related to long term outcomes supporting its clinical use. The prohibitive cost of 3D models, the specialized manpower it necessitates and the need for specific instrumentation are major deterrents to widespread use of this technology, particularly in small-scale healthcare setups. With further advancements in technology, the goal must be to make it more accurate and affordable to hospitals and patients so that the benefits of the technology can reach a wider patient population.

Thoracic Pedicle Screw Placement Utilizing Hands-On Training Session on Three-Dimensional Models

The utilization of three-dimensional (3D) models has been an important element of medical education. We demonstrate a three-dimensionally-printed (3DP) thoracic spine model for use in the teaching of freehand pedicle screw placement. Neurosurgical residents with varying years of experience practiced screw placement on these models. Residents were timed, and models were evaluated for medial and lateral breaches. Overall, this technical report describes the utility of 3D spine models in the training of thoracic pedicle screw placement. The tactile feedback from the 3D models was designed to represent both cortical and cancellous bones.

Creation of a three-dimensional printed spine model for training in pain procedures

OBJECTIVE

Technological developments have made it possible to create simulation models to educate clinicians on surgical techniques and patient preparation. In this study, we created an inexpensive lumbar spine phantom using patient data and analyzed its usefulness in clinical education.

METHODS

This randomized comparative study used computed tomography and magnetic resonance imaging data from a single patient to print a three-dimensional (3D) bone framework and create a mold. The printed bones and structures made from the mold were placed in a simulation model that was used to train residents. The residents were divided into two groups: Group L, which received only an audiovisual lecture, and Group P, which received an additional 1 hour of training using the 3D phantom. The performance of both groups was evaluated using pretest and post-test analyses.

RESULTS

Both the checklist and global rating scores increased after training in both groups. However, some variables improved significantly only in Group P. The overall satisfaction score was also higher in Group P than in Group L.

CONCLUSIONS

We have described a method by which medical doctors can create a spine simulation phantom and have demonstrated its efficiency for procedural education.

Training of CT-guided Periradicular Therapy in a Realistic Simulation Environment - Evaluation and Recommendations for a Training Curriculum

RATIONALE AND OBJECTIVES

To evaluate the training of computed tomography (CT)-guided periradicular therapy in a realistic simulation environment and to derive recommendations for a training curriculum.

MATERIALS AND METHODS

A novel simulation environment including the use of a 3D printed, patient-mimicking phantom was used to train medical students to perform CT-guided periradicular therapy of the lumbar spine. Seventeen participants underwent three training sessions (day 0, day 7, and after day 28) with six procedures per session. Procedure duration and the number of fluoroscopy image acquisitions were recorded. Participants' performance was assessed by an independent investigator using a six-point checklist scale (0 = lowest, 6 = highest). In addition, participants self-evaluated their skills and the simulation training in questionnaires.

RESULTS

Procedure durations and image acquisitions decreased after one training session (p < 0.001) without further improvement thereafter (p > 0.6). They also decreased within training sessions and were lowest after five procedures in all sessions. Performance scores improved after the first session to nearly perfect scores in the second session (mean 5.7; 95%CI: 5.5-6.0; p < 0.001) and decreased again in the third session (mean 4.9; 95%CI: 4.6-5.3; p = 0.008). Participants were satisfied with their training progress and felt adequately prepared to perform CT-guided periradicular therapies on patients after the training.

CONCLUSION

Simulation-based training of CT-guided periradicular therapy in a realistic environment is effective and should ideally be performed with one training session consisting of five procedures shortly before treating the first patient.

Three-Dimensional Printing for Preoperative Planning and Pedicle Screw Placement in Adult Spinal Deformity: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

This current systematic review seeks to identify current applications and surgical outcomes for 3-dimensional printing (3DP) in the treatment of adult spinal deformity.

METHODS

A comprehensive search of publications was conducted through literature databases using relevant keywords. Inclusion criteria consisted of original studies, studies with patients with adult spinal deformities, and studies focusing on the feasibility and/or utility of 3DP technologies in the planning or treatment of scoliosis and other spinal deformities. Exclusion criteria included studies with patients without adult spinal deformity, animal subjects, pediatric patients, reviews, and editorials.

RESULTS

Studies evaluating the effect of 3DP drill guide templates found higher screw placement accuracy in the 3DP cohort (96.9%), compared with non-3DP cohorts (81.5%, P < .001). Operative duration was significant decreased in 3DP cases (378 patients, 258 minutes) relative to non-3DP cases (301 patients,272 minutes, P < .05). The average deformity correction rate was 72.5% in 3DP cases (245 patients). There was no significant difference in perioperative blood loss between 3DP (924.6 mL, 252 patients) and non-3DP cases (935.6 mL, 177 patients, P = .058).

CONCLUSIONS

Three-dimensional printing is currently used for presurgical planning, patient and trainee communication and education, pre- and intraoperative guides, and screw drill guides in the treatment of scoliosis and other adult spinal deformities. In adult spinal deformity, the usage of 3DP guides is associated with increased screw accuracy and favorable deformity correction outcomes; however, average costs and production lead time are highly variable between studies.

Systematic review of three-dimensional printing for simulation training of interventional radiology trainees

RATIONALE AND OBJECTIVES

Three-dimensional (3D) printing has been utilized as a means of producing high-quality simulation models for trainees in procedure-intensive or surgical subspecialties. However, less is known about its role for trainee education within interventional radiology (IR). Thus, the purpose of this review was to assess the state of current literature regarding the use of 3D printed simulation models in IR procedural simulation experiences.

MATERIALS AND METHODS

A literature query was conducted through April 2020 for articles discussing three-dimensional printing for simulations in PubMed, Embase, CINAHL, Web of Science, and the Cochrane library databases using key terms relating to 3D printing, radiology, simulation, training, and interventional radiology.

RESULTS

We identified a scarcity of published sources, 4 total articles, that appraised the use of three-dimensional printing for simulation training in IR. While trainee feedback is generally supportive of the use of three-dimensional printing within the field, current applications utilizing 3D printed models are heterogeneous, reflecting a lack of best practices standards in the realm of medical education.

CONCLUSIONS

Presently available literature endorses the use of three-dimensional printing within interventional radiology as a teaching tool. Literature documenting the benefits of 3D printed models for IR simulation has the potential to expand within the field, as it offers a straightforward, sustainable, and reproducible means for hands-on training that ought to be standardized.

Lumbar Vertebrae Synthetic Segmentation in Computed Tomography Images Using Hybrid Deep Generative Adversarial Networks

The lumbar vertebrae segmentation in Computed tomography (CT) is challenging due to the scarcity of the labeled training data that we define as paired training data for the deep learning technique. Much of the available data is limited to the raw CT scans, unlabeled by radiologists. To handle the scarcity of labeled data, we utilized a hybrid training system by combining paired and unpaired training data and construct a hybrid deep segmentation generative adversarial network (Hybrid-SegGAN). We develop a total automatic approach for lumbar vertebrae segmentation in CT images using Hybrid-SegGAN for synthetic segmentation. Our network receives paired and unpaired data, discriminates between the two sets of data, and processes each through separate phases. We used CT images from 120 patients to demonstrate the performance of the proposed method and extensively evaluate the segmentation results against their ground truth by using 12 performance measures. The result analysis of the proposed method suggests its feasibility to improve the capabilities of deep learning segmentation without demanding the time-consuming annotation procedure for labeled and paired data.

Investigation and Feasibility of Combined 3D Printed Thermoplastic Filament and Polymeric Foam to Simulate the Cortiocancellous Interface of Human Vertebrae

Disorders of the spine are among the most common indications for neurosurgical and orthopedic surgical interventions. Spinal fixation in the form of pedicle screw placement is a common form of instrumentation method in the lower cervical, thoracic, and lumbar spine. A vital principle to understand for the safe and accurate placement of pedicle screws is the palpable difference between the cortical and cancellous bone, both of which have different material properties and compositions. Probing and palpation of the hard cortical bone, also known as the “ventral lamina”, covering the neural elements of the spinal canal during screw placement provides manual feedback to the surgeon, indicating an impending breach if continued directional force is applied. Generally, this practice is learned at the expense of patients in live operating room scenarios. Currently, there is a paucity of human vertebra simulation designs that have been validated based on the in vivo ultrastructure and physical properties of human cortical and cancellous bone. In this study, we examined the feasibility of combining three-dimensionally printed thermoplastic polymers with polymeric foam to replicate both the vertebral corticocancellous interface and surface anatomy for procedural education.

3D printed CT-based abdominal structure mannequin for enabling research

An anthropomorphic phantom is a radiologically accurate, tissue realistic model of the human body that can be used for research into innovative imaging and interventional techniques, education simulation and calibration of medical imaging equipment. Currently available CT phantoms are appropriate tools for calibration of medical imaging equipment but have major disadvantages for research and educational simulation. They are expensive, lacking the realistic appearance and characteristics of anatomical organs when visualized during X-ray based image scanning. In addition, CT phantoms are not modular hence users are not able to remove specific organs from inside the phantom for research or training purposes. 3D printing technology has evolved and can be used to print anatomically accurate abdominal organs for a modular anthropomorphic mannequin to address limitations of existing phantoms. In this study, CT images from a clinical patient were used to 3D print the following organ shells: liver, kidneys, spleen, and large and small intestines. In addition, fatty tissue was made using modelling beeswax and musculature was modeled using liquid urethane rubber to match the radiological density of real tissue in CT Hounsfield Units at 120kVp. Similarly, all 3D printed organ shells were filled with an agar-based solution to mimic the radiological density of real tissue in CT Hounsfield Units at 120kVp. The mannequin has scope for applications in various aspects of medical imaging and education, allowing us to address key areas of clinical importance without the need for scanning patients.