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Background: Three-dimensional weightbearing CT (WBCT) has been widely used to assess foot and ankle alignment. However, most current measurement methods are based on 2-dimensional concepts—distance, long axis, angulation, etc—and are sensitive to changes in orientation of the WBCT images. This study demonstrated how changes in positioning of the image can significantly influence the evaluation of hindfoot alignment. Methods: WBCT scans of 10 feet without deformities were used. In the horizontal view, the long axis of the foot image was aligned to a neutral position and then rotated 5, 10, 15, and 20 degrees both internally and externally to simulate malposition. The Calcaneal Moment Arm (CMA) was measured by 2 investigators independently in the above positions. An intraclass correlation coefficient (ICC) model was used to assess the intra- and interobserver reliabilities. The correlation between the CMA and the rotation angle of the foot images was analyzed using linear regression. Results: The CMA measurements demonstrated that internal rotation of the image changed the neutral hindfoot into valgus, whereas external rotation led to varus. A 1-degree internal or external rotation of the image correlated with 0.48 (±0.03) mm increase or decrease in the modified WBCT-CMA value (P <.0001, R 2 = 0.6406). Conclusion: This study demonstrated that although 3D WBCT provides the ability to observe the foot from different perspectives, current alignment evaluation tools are limited to 2 dimensions. Therefore, positioning the WBCT images in a consistent orientation is important to generate correct data. [ABSTRACT FROM AUTHOR]

Automated segmentation of 3-dimensional pulp space on cone-beam computed tomography images presents a significant opportunity for enhancing diagnosis, treatment planning, and clinical education in endodontics. The aim of this systematic review was to investigate the performance of artificial intelligence-driven automated pulp space segmentation on cone-beam computed tomography images. A comprehensive electronic search was performed using PubMed, Web of Science, and Cochrane databases, up until February 2024. Two independent reviewers participated in the selection of studies, data extraction, and evaluation of the included studies. Any disagreements were resolved by a third reviewer. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the risk of bias. Thirteen studies that met the eligibility criteria were included. Most studies demonstrated high accuracy in their respective segmentation methods, although there was some variation across different structures (pulp chamber, root canal) and tooth types (single-rooted, multirooted). Automated segmentation showed slightly superior performance for segmenting the pulp chamber compared to the root canal and single-rooted teeth compared to multi-rooted ones. Furthermore, the second mesiobuccal (MB2) canalsegmentation also demonstrated high performance. In terms of time efficiency, the minimum time required for segmentation was 13 seconds. Artificial intelligence-driven models demonstrated outstanding performance in pulp space segmentation. Nevertheless, these findings warrant careful interpretation, and their generalizability is limited due to the potential risk and low evidence level arising from inadequately detailed methodologies and inconsistent assessment techniques. In addition, there is room for further improvement, specifically for root canal segmentation and testing of artificial intelligence performance in artifact-induced images. [ABSTRACT FROM AUTHOR]

Three-dimensional printing (3DP) is being integrated into surgical practice at a significant pace, from preprocedural planning to procedure simulation. 3DP is especially useful in surgical education, where printed models are highly accurate and customizable. The aim of this study was to evaluate how 3DP is being integrated most recently into surgical residency training. We performed a structured literature search of the OVID/MEDLINE, EMBASE, and PUBMED databases following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Articles published from 2016 to 2023 that met predefined inclusion and exclusion criteria were included. Data extracted included surgical subspecialty using 3DP, application of 3DP, and any reported satisfaction measures of trainees. A thorough analysis of pooled data was performed to evaluate satisfaction rates among studies. A total of 85 studies were included. The median number of participants was 18 (interquartile range 10-27). Fourteen surgical disciplines were represented, with ear, nose, and throat/otolaryngology having the highest recorded utilization of 3DP models among residents and medical students (22.0%), followed by neurosurgery (14.0%) and urology (12.0%). 3DP models were created most frequently to model soft tissue (35.3%), bone (24.7%), vessel (14.1%), mixed (16.4%), or whole organs (6.66%) (Fig.1). Feedback from trainees was overwhelmingly positive regarding the fidelity of the models and their support for integration into their training programs. Among trainees, the combined satisfaction rate with their use in the curriculum was 95% (95% confidence interval, 0.92-0.97), and the satisfaction rate with the model fidelity was 90% (95% confidence interval, 0.86-0.94). There is wide variation in the surgical specialties utilizing 3DP models in training. These models are effective in increasing trainee comfort with both common and rare scenarios and are associated with a high degree of resident support and satisfaction. Plastic surgery programs may benefit from the integration of this technology, potentially strengthening future surgical curricula. Objective evaluations of their pedagogic effects on residents are areas of future research. [ABSTRACT FROM AUTHOR]

The increasing application of virtual surgical planning (VSP) in orthognathic surgery implies a critical need for accurate prediction of facial and skeletal shapes. The craniofacial relationship in patients with dentofacial deformities is still not understood, and transformations between facial and skeletal shapes remain a challenging task due to intricate anatomical structures and nonlinear relationships between the facial soft tissue and bones. In this study, a novel bidirectional 3-dimensional (3D) deep learning framework, named P2P-ConvGC, was developed and validated based on a large-scale data set for accurate subject-specific transformations between facial and skeletal shapes. Specifically, the 2-stage point-sampling strategy was used to generate multiple nonoverlapping point subsets to represent high-resolution facial and skeletal shapes. Facial and skeletal point subsets were separately input into the prediction system to predict the corresponding skeletal and facial point subsets via the skeletal prediction subnetwork and facial prediction subnetwork. For quantitative evaluation, the accuracy was calculated with shape errors and landmark errors between the predicted skeleton or face with corresponding ground truths. The shape error was calculated by comparing the predicted point sets with the ground truths, with P2P-ConvGC outperforming existing state-of-the-art algorithms including P2P-Net, P2P-ASNL, and P2P-Conv. The total landmark errors (Euclidean distances of craniomaxillofacial landmarks) of P2P-ConvGC in the upper skull, mandible, and facial soft tissues were 1.964 ± 0.904 mm, 2.398 ± 1.174 mm, and 2.226 ± 0.774 mm, respectively. Furthermore, the clinical feasibility of the bidirectional model was validated using a clinical cohort. The result demonstrated its prediction ability with average surface deviation errors of 0.895 ± 0.175 mm for facial prediction and 0.906 ± 0.082 mm for skeletal prediction. To conclude, our proposed model achieved good performance on the subject-specific prediction of facial and skeletal shapes and showed clinical application potential in postoperative facial prediction and VSP for orthognathic surgery. [ABSTRACT FROM AUTHOR]

In the recent paper "On a formula for sets of constant width in 2D, Comm. Pure Appl. Anal. 18 (2019), 2117–2131", we gave a constructive formula for all 2d sets of constant width. Based on this result we derive here a formula for the parametrization of the boundary of bodies of constant width in 3 dimensions, with the formula depending on one function defined on S 2 . Each such function gives a minimal value r 0 and for all r ≥ r 0 one finds a body of constant width 2r. Moreover, we show that all bodies of constant width in 3d have such a parametrization. The last result needs a tool that we describe as 'shadow domain' and which is explained in an appendix. The construction is explicit and offers a parametrization different from the one given by T. Bayen, T. Lachand-Robert and É. Oudet in "Analytic parametrization of three-dimensional bodies of constant width. Arch. Ration. Mech. Anal., 186 (2007), 225–249". [ABSTRACT FROM AUTHOR]

Background: 3D visualization systems in laparoscopic surgery have been proposed to improve manual task handling compared to 2D, however, few studies have compared the intra‐operative efficacy in laparoscopic cholecystectomy (LC). The aim of this study is to determine if there is a benefit in intra‐operative efficiency when using a 3D visualization system in difficult LC compared to traditional 2D visualization systems. Method s : Retrospective analysis of 'difficult' LCs (Grades 3 or 4) was completed. The assessor was blinded as all cases were recorded and viewed in 2D only. Variables collected included time to complete steps, missed hook diathermy attempts, failed grasp attempts, missed clip attempts and preparation steps for intra‐operative cholangiogram (IOC). Multiple linear regression was undertaken for time variables, Poisson regression or negative binomial regression was completed for continuous variables. Results: Fifty‐two operative videos of 'difficult' LC were reviewed. 3D systems were associated with reduced operative times, although this was not statistically significant (CI: −2.93–14.93, P‐value = 0.183). Dissection of the anterior fold to achieve the critical view of safety was significantly faster by 3.55 min (CI: 1.215–9.206, P‐value = 0.002), and with considerably fewer errors when using 3D systems. Fewer IOC preparation errors were observed with a 3D system compared with a 2D system. Conclusions: 3D systems appear to enhance operator efficiency, allowing faster completion of critical steps with fewer errors. This pilot study underscores the utility of video annotation for intra‐operative assessment and suggests that, in larger multi‐centre studies, 3D systems may demonstrate superior intra‐operative efficiency over 2D systems during a 'difficult' LC. [ABSTRACT FROM AUTHOR]

The University of Johannesburg has integrated serious games into its teaching, exemplified by Codebreakers, a 2D game teaching information theory. While successful, Codebreakers lacked personalisation and used a criticised assessment method based on answer streaks. Knowledge tracing algorithms, known for their effectiveness in intelligent tutoring systems, were considered to address these limitations. This led to the research question: "Can a new serious game be designed, incorporating knowledge tracing algorithms to deliver personalised learning experiences in telecommunications education?" In response, an escape-themed serious game was developed, integrating Bayesian Knowledge Tracing as a statistical student model for personalised learning. This innovative approach combines free-roam gameplay with tailored educational content, significantly advancing serious game design. While primarily aimed at enhancing Codebreakers, this new game contributes substantially to serious game theory by successfully implementing personalised learning within an engaging format. The project showcases the potential of knowledge tracing algorithms in creating adaptive, student-centered learning experiences within the context of educational games. [ABSTRACT FROM AUTHOR]

Background: Unintended secondary changes in the posterior tibial slope (PTS) and tibial torsion angle (TTA) may occur after medial open-wedge high tibial osteotomy (MOWHTO). In surgical procedures using patient-specific instruments (PSIs), it is essential to reproduce the PTS and TTA that were planned in simulations. Purpose: To analyze the factors causing unintended sagittal and axial alignment changes after MOWHTO. Study Design: Case series; Level of evidence, 4. Methods: Overall, 63 patients (70 knees) who underwent MOWHTO using a PSI between June 2020 and June 2023 were retrospectively reviewed. Preoperative and postoperative computed tomography scans were 3-dimensionally reconstructed. Simulated osteotomy was performed so that the weightbearing line could pass through the target point. A PSI gapper was 3-dimensionally printed to fit the posteromedial corner of the osteotomy gap in the simulated HTO model. After MOWHTO using the PSI gapper, the actual postoperative model was compared with the preoperative or simulation model. This assessment included PTS, TTA, hinge axis, and osteotomy-related parameters. Cortical breakage around the lateral hinge was evaluated to assess stability. Results: The mean PTS and TTA did not change in the simulation. However, significant changes were observed in the actual postoperative PTS and TTA (change, –2.4°± 2.2° and −3.9°± 4.7°, respectively). The PTS was reduced, while the TTA decreased with internal rotation of the distal fragment. The difference in the axial hinge axis angle (AHA) between the simulation and actual surgery was the factor most correlated with the difference in the PTS (r = 0.625; P <.001). In regression analysis, the difference in the AHA was the only factor associated with the difference in the PTS (β = 0.558; P =.001), and there were no factors that showed any significant associations with the difference in the TTA. In subgroup analyses for the change in the TTA, the correction angle and anterior osteotomy angle were significantly higher in the more internal rotation group (P =.023 and P =.010, respectively). The TTA change was significantly higher in the unstable group with lateral cortical breakage (P =.018). The unstable group was more likely to show an internal rotation of ≥5° (odds ratio, 5.0; P =.007). Conclusion: The AHA was associated with a difference in the PTS between the simulation and actual surgery. The change in the TTA was caused by a combination of multiple factors, such as a large correction angle and anterior osteotomy angle, but mainly by instability of the lateral cortical hinge. [ABSTRACT FROM AUTHOR]

Background: Assessment of 3-dimensional (3D) femoral head coverage is critical in evaluating, preoperative planning, and treating hip dysplasia. Purpose: To (1) propose a mathematical model to establish 3D femoral head coverage using conventional computed tomography (CT), (2) determine the correlation of 2D parameters with 3D coverage, and (3) characterize the patterns of dysplasia based on 3D morphology. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We identified 30 patients (n = hips) with symptomatic dysplasia and 30 patients (n = hips) without dysplasia. Patients with dysplastic hips were matched with regard to sex, age, and body mass index to those with nondysplastic hips. Preoperative CTs were analyzed using 3D software, and 3D femoral head surface area coverage (FHSAC; in %) was assessed in 4 quadrant zones: anteromedial, anterolateral, posteromedial, and posterolateral. To assess lateral coverage of the femoral head, we introduced the anterolateral femoral head coverage angle (ALFC) and the posterolateral femoral head coverage angle (PLFC). Results: Reduced femoral head coverage was more pronounced in dysplastic versus nondysplastic hips in the anterolateral quadrant (18% vs 40.7%, respectively) and posterolateral quadrant (35.8% vs 56.9%, respectively) (P <.0001 for both). Dysplastic hips had smaller ALFC and PLFC (18.4° vs 38.7°; P <.0001; 47.2° vs 72.3°; P =.0002). Anterolateral and posterolateral FHSAC were strongly correlated with the ALFC (r = 0.88; P <.0001) and the PLFC (r = 0.82; P <.0001) along with the lateral center-edge angle (anterolateral, r = 0.75; P <.0001; posterolateral, r = 0.73; P <.0001). Prediction models established for FHSAC had strong agreement with explanatory CT variables (anterolateral: r = 0.91; P <.0001; posterolateral: r = 0.90; P <.0001). The cutoff values for anterolateral and posterolateral FHSAC were 25% and 41%, respectively. In dysplastic hips, global deficiency was most common (15/30 hips), 9 hips showed an anterolateral deficiency, and 4 hips had a posterolateral deficiency pattern. Conclusion: The ALFC and The PLFC were strongly correlated with 3D lateral FHSAC and were able to predict 3D coverage accurately. [ABSTRACT FROM AUTHOR]

Background: The paranasal depression is a common facial feature of Oriental populations. One of the most wildly used method to improve it was paranasal augmentation using expanded polytetrafluoroethylene (ePTFE). The effectiveness of it should be tested by three-dimensional morphological measurements. Methods: Patients who underwent paranasal augmentation using ePTFE between January 2017 and December 2022 were recruited in the study. The preoperative and postoperative clinical variables and three-dimensional measurement of patients were also collected. The satisfaction outcome were assessed. Results: By establishing a coordinate system based on the Frankfurt plane, 16 landmarks including nasal alar crest, subnasal point, upper lip, pogonion, glabella, sub-cheek, orbitale, tragion in left and right side of faces were marked. Five segments, 4 ratios, and 3 angles were measured based on it. The significant increase of segments, ratios, and angles indicated that paranasal augmentation could increase the protrusion of paranasal area, both in absolute value and relative proportion. The significant decrease of other data indicated that the protrusion difference between paranasal base and upper lip, forehead, and chin, respectively, were shortened after surgery. The average size of implant was 6.54 ± 1.02 mm, and the average increase of paranasal height was 4.38 ± 1.04 mm postoperatively. This indicates that two-thirds of its height will ultimately be reflected effectively in the sagittal elevation of the paranasal base. Conclusions: Paranasal augmentation using ePTFE could effectively increase paranasal height and improve subunits relationships, and the ePTFE prosthesis should be designed and carve considering the 1/3 loss of height after implantation. Level of Evidence III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

Stent underexpansion in calcified coronary stenosis is an important predictor of major short- and long-term adverse cardiovascular events. In this case, we describe a novel method for assessing stent expansion using 3-dimensional stent reconstruction with C-arm motion compensated computed tomography.

Abstract Deconstructing surgeries into steps and providing instructions with illustrations has been the staple of surgical textbooks for decades. However, it may be difficult for the novice surgeon to interpret 2‐dimensional (2D) illustrations into 3D surgeries. The objective of this study is to create operable models that demonstrate the progression of surgery in 3D and allow for mastering the final steps of the operation first. Mastoidectomy was performed in a stepwise fashion to different end points on 5 identical 3D‐printed temporal bone models to represent 5 major steps of the operation. The drilled models were computed tomography scanned and the subsequent images were used to create 3D model copies of each step. This is the first study to demonstrate that it is possible to create, scan, and copy stepwise, operable, patient‐specific 3D‐printed models, which the trainee can both reference as a 3D dissection guide and can operate on repeatedly and in any order.

Background: Laparoscopic cholecystectomy is a common procedure for the definitive treatment for cholecystitis and symptomatic cholelithiasis. One advancement in minimally invasive surgery has been the development of three-dimensional (3D) visualization systems to provide stereopsis. It is yet to be determined whether this innovation is beneficial to the surgeon or simply just a gimmick. This narrative review aims to answer the following research question, what is the impact of 3D visualization systems on surgical efficiency compared with two-dimensional visualization systems in laparoscopic cholecystectomy? Methods: Through a broad literature search it was determined that operative time and intraoperative errors have been used in published research to assess intraoperative efficiency. Results: Studies published to date have used operative time, intraoperative errors, and intraoperative bleeding as current measures for intraoperative efficiency. Previous meta-analysis have shown a slight improvement in operative time for 3D visualization systems; however, subsequent randomized control trials have not shown a significant difference in operative time. Reporting of intraoperative errors has been quite subjective and a difference between visualisation modality has not been shown. Conclusion: 3D visualization systems have shown a minor improvement in operative time compared with traditional laparoscopic systems and it is unlikely to be of any clinical significance. Studies that measure intraoperative error vary greatly in what they report, and which assessment tool is used. Across existing literature, studies do not control for surgeon's experience, elective/emergent cases, and grade of gallbladder/difficulty. Further research is required, using novel tools for assessment in laparoscopic cholecystectomy to determine intraoperative differences through objective and quantitative variables. [ABSTRACT FROM AUTHOR]

Methods for assessing three-dimensional (3D) breast volume are becoming increasingly popular in breast surgery. However, the precision of intraoperative volumetric assessment is still unclear. Until now, only non-validated scanning systems have been used for intraoperative volumetric analyses. This study aimed to assess the feasibility, handling, and accuracy of a commercially available, validated, and portable device for intraoperative 3D volumetric evaluation. All patients who underwent breast surgery from 2020 to 2022 were identified from our institutional database. Intraoperative 3D volumetric assessments of 103 patients were included in this study. Standardized 3D volumetric measurements were obtained 3 months postoperatively to compare the intraoperatively generated volumetric assessment. All of the study participants were women with a mean age of 48.3 ± 14.7 years (range: 20–89). The mean time for intraoperative volumetric assessment was 8.7 ± 2.6 min. The postoperative 3D volumetric assessment, with a mean volume of 507.11 ± 206.29 cc, showed no significant difference from the intraoperative volumetric measurements of 504.24 ± 276.61 cc (p = 0.68). The mean absolute volume difference between the intraoperative simulations and postoperative results was 27.1 cc. Intraoperative 3D volumetric assessment using the VECTRA H2 imaging system seems to be a feasible, reliable, and accurate method for measuring breast volume. Based on this finding, we plan to investigate whether volumetric objective evaluations will help to improve breast symmetry in the future. [ABSTRACT FROM AUTHOR]

Three dimensional models of cell culture enables researchers to recreate aspects of tumour biology not replicated by traditional two dimensional techniques. Here we describe a protocol to enable automated high throughput phenotypic profiling across panels of patient derived glioma stem cell spheroid models. We demonstrate the use of both live/dead cell end-points and monitor the dynamic changes in the cell cycle using cell lines expressing the FUCCI cell cycle reporter. Together, these assays provide additional insight into the mechanism of action of compound treatments over traditional cell viability assay endpoints.

This study aimed to (1) measure acetabular sector angle (ASA) from proximal to distal positions along the axial femoral head axis, (2) identify acetabular deficiency patterns, and (3) correlate ASA at different axial positions with other radiological measurements in acetabular dysplasia. We identified 30 hips with dysplasia (lateral center edge angle [LCEA] <20°) and 30 hips without dysplasia (LCEA >25°) from a retrospective cohort. Anterior and posterior ASA (AASA, PASA) were measured in the axial computed tomography plane through the femoral head center (equatorial) and two axial positions above the equatorial line (intermediate and proximal). Deficiency patterns were identified using ASA cut‐off values determined from receiver operating characteristic curves. Pearson's coefficients were used for correlations. Compared to non‐dysplastic hips, AASA in dysplastic hips was significantly smaller in all levels: equatorial (46.1 ± 7.3 vs. 54.9 ± 8.5,° p < 0.001), intermediate (62.1 ± 11.2 vs. 69.0 ± 10.6,° p = 0.02), and proximal (102.9 ± 14.2 vs. 128.3 ± 23.0,° p < 0.001). According to proximal ASA (Pro‐ASA) cut‐off values in dysplastic hips, global deficiency was most prevalent (19/30, 63.3%), followed by anterior (6/30, 20%) and posterior (3/30, 10%) deficiency. There were strong correlations between acetabular anteversion and Eq‐AASA (r = −0.74, p < 0.001) and LCEA and pro‐PASA (r = 0.82, p < 0.001). Clinical significance: Acetabular sector angle provides insight into acetabular morphology and patterns of deficiency, providing essential information for precise acetabular reorientation. [ABSTRACT FROM AUTHOR]

Humans have different 3-dimensional biomechanical characteristics of the lower extremities during locomotion with one and both legs. These biomechanical characteristics may also be observed in the weightlifting derivatives. This study aimed to compare the 3-dimensional joint kinetics of the lower extremities during the single-leg hang power clean (SHPC) and double-leg hang power clean (DHPC). Ten male track and field athletes performed the SHPC and DHPC using external loads of 30, 60, and 90% of one repetition maximum (1RM). The 1RMs in SHPC and DHPC were measured separately, and the external loads at 30, 60, and 90% of the 1RM used were determined based on the different 1RMs in SHPC and DHPC. We calculated the joint moment and joint power of the SHPC and DHPC using a motion capture system and force platforms. The hip abduction moment and power of the SHPC were significantly greater than those of the DHPC under all external loads (p < 0.05). In addition, ankle joint moment at all external loads and joint power at 90% of 1RM was greater for SHPC than for DHPC (p < 0.05). Furthermore, although hip (extension-flexion) and ankle joint kinetics in SHPC and DHPC showed similar load dependence, hip abduction axis kinetics was not load dependent. These results suggest that the hip (abduction-adduction) and ankle joint kinetics in SHPC are greater than in DHPC, but hip (abduction-abduction) kinetics in SHPC is not load independent. Comparison of joint-level kinetics during single- and double-leg weightlifting derivatives. J Strength Cond Res 37(5): 1017–1022, 2023—Humans have different 3-dimensional biomechanical characteristics of the lower extremities during locomotion with one and both legs. These biomechanical characteristics may also be observed in the weightlifting derivatives. This study aimed to compare the 3-dimensional joint kinetics of the lower extremities during the single-leg hang power clean (SHPC) and double-leg hang power clean (DHPC). Ten male track and field athletes performed the SHPC and DHPC using external loads of 30, 60, and 90% of one repetition maximum (1RM). The 1RMs in SHPC and DHPC were measured separately, and the external loads at 30, 60, and 90% of the 1RM used were determined based on the different 1RMs in SHPC and DHPC. We calculated the joint moment and joint power of the SHPC and DHPC using a motion capture system and force platforms. The hip abduction moment and power of the SHPC were significantly greater than those of the DHPC under all external loads (p < 0.05). In addition, ankle joint moment at all external loads and joint power at 90% of 1RM was greater for SHPC than for DHPC (p < 0.05). Furthermore, although hip (extension-flexion) and ankle joint kinetics in SHPC and DHPC showed similar load dependence, hip abduction axis kinetics was not load dependent. These results suggest that the hip (abduction-adduction) and ankle joint kinetics in SHPC are greater than in DHPC, but hip (abduction-abduction) kinetics in SHPC is not load independent. [ABSTRACT FROM AUTHOR]

Background: We used antibiotic-impregnated polymethylmethacrylate (PMMA) bone cement to make a patient-specific radial head prosthesis (RHP) by applying the 3-dimensional (3D) designing technique in patients with Mason types 3 and 4 radial head fractures. The aim of this study is to report the short- to mid-term outcomes of this procedure. Methods: This is a prospective study of all patients who underwent a patient-specific PMMA bone cement RHP at our institute over a 1-year period from May 2017 to June 2018. The outcome measures included range of motion, grip strength, visual analogue scale (VAS) for pain at rest and at activity, disabilities of arm, shoulder and hand (DASH) score and Mayo elbow performance index (MEPI). Radiographs of the elbow ere obtained at final follow-up and any complications were also recorded. Results: Our study included eight patients with a mean follow-up of 18 months (13–20 months). The mean arc of extension–flexion and supination–pronation of the operated side was 86% and 96% of the unaffected side, respectively. Mean grip strength was 86% of the unaffected side. The mean VAS for pain at rest was 0 and during activity was 2 out of 10. The mean DASH score was 8 out of 100 (0–22), showing minimal disability and ability to cope with most living activities. MEPI showed four excellent, three good and one fair result. One patient complained of proximal forearm pain that appeared 1 year after surgery. No patient complained of ulnar nerve symptoms requiring intervention. No RHP was removed during the follow-up. Conclusions: PMMA RHP can be used safely as an alternative to metal prostheses to restore valgus and axial stability of the forearm. The use of 3D printing optimised the design and surgical technique of radial head arthroplasty, and we need further studies to assess the long-term follow-ups. Level of Evidence: Level IV (Therapeutic) [ABSTRACT FROM AUTHOR]

Insoles are used to treat various foot diseases, including plantar foot, diabetic foot ulcers, and refractory plantar fasciitis. In this study, we investigated the effects of 3-dimensional image-based (3-D) insole in healthy volunteers with no foot diseases. Additionally, the comfort of the 3-D insole was compared with that of a custom-molded insole. A singlecenter, randomized, open clinical trial was conducted to address the effectiveness of insole use in a healthy population with no foot or knee disease. Two types of arch support insoles were evaluated for their effectiveness: a 3-D insole and a custom-molded insole. Fifty Korean volunteers participated in the study and were randomly allocated into the "3-D insole" (n = 40) or "custom-molding insole" (n = 10) groups. All subjects wore 3-D insoles or custommolded insoles for 2 weeks. The sense of wearing shoes (Visual Analog Scale [VAS] and score) and fatigue of the foot were used to assess the insole effects at the end of the 2-week study period. The 3-D insole groups showed significantly improved sense of wearing shoes (VAS, p = 0.0001; score, p = 0.0002) and foot fatigue (p = 0.0005) throughout the study period. Although the number of subjects was different, the custom-molding insole group showed no significant changes in the sense of wearing shoes (VAS, 0.1188; score, p = 0.1483). Foot fatigue in the 3-D insole group improved significantly (p = 0.0005), which shows that a 3-D insole might have favorable effects on foot health in a healthy population. [ABSTRACT FROM AUTHOR]

Abstract Background The therapeutic IgG1 anti-CD20 antibody, rituximab (RTX), has greatly improved prognosis of many B-cell malignancies. Despite its success, resistance has been reported and detailed knowledge of RTX mechanisms are lacking. Complement-dependent cytotoxicity (CDC) is one important mode of action of RTX. The aim of this study was to systematically evaluate factors influencing complement-mediated tumor cell killing by RTX. Methods Different RTX isotypes, IgG1, IgG3, IgA1 and IgA2 were evaluated and administered on four human CD20+ B-cell lymphoma cell lines, displaying diverse expression of CD20 and complement-regulatory protein CD59. Complement activation was assessed on lymphoma cells grown in 2 and 3-dimensional (3D) culture systems by trypan blue exclusion. CDC in 3D spheroids was additionally analyzed by Annexin V and propidium iodide staining by flow cytometry, and confocal imaging. Anti-CD59 antibody was used to evaluate influence of CD59 in RTX-mediated CDC responses. Statistical differences were determined by one-way ANOVA and Tukey post hoc test. Results We found that 3 out of 4 lymphomas were sensitive to RTX-mediated CDC when cultured in 2D, while 2 out of 4 when grown in 3D. RTX-IgG3 had the greatest CDC potential, followed by clinical standard RTX-IgG1 and RTX-IgA2, whereas RTX-IgA1 displayed no complement activation. Although the pattern of different RTX isotypes to induce CDC were similar in the sensitive lymphomas, the degree of cell killing differed. A greater CDC activity was seen in lymphoma cells with a higher CD20/CD59 expression ratio. These lymphomas were also sensitive to RTX when grown in 3D spheroids, although the CDC activity was substantially reduced compared to 2D cultures. Analysis of RTX-treated spheroids demonstrated apoptosis and necrosis essentially in the outer cell-layers. Neutralization of CD59 overcame resistance to RTX-mediated CDC in 2D-cultured lymphoma cells, but not in spheroids. Conclusions The results demonstrate that CDC outcome in CD20+ B-cell lymphoma is synergistically influenced by choice of RTX isotype, antigen density, tumor structure, and degree of CD59 expression. Assessment of tumor signatures, such as CD20/CD59 ratio, can be advantageous to predict CDC efficiency of RTX in vivo and may help to develop rational mAbs to raise response rates in patients.

Purpose: Flocculated cohesive suspended sediments (flocs) play an important role in all aquatic environments, facilitating the transport and deposition of sediment and associated contaminants with consequences for aquatic health, material fluxes, and morphological evolution. Accurate modelling of the transport and behaviour of these sediments is critical for a variety of activities including fisheries, aquaculture, shipping, and waste and pollution management and this requires accurate measurement of the physical properties of flocs including porosity. Methods: Despite the importance of understanding floc porosity, measurement approaches are indirect or inferential. Here, using μCT, a novel processing and analysis protocol, we directly quantify porosity in natural sediment flocs. For the first time, the complexity of floc pore spaces is observed in 3-dimensions, enabling the identification and quantification of important pore space and pore network characteristics, namely 3D pore diameter, volume, shape, tortuosity, and connectivity. Results: We report on the complexity of floc pore space and differentiate effective and isolated pore space enabling new understanding of the hydraulic functioning of floc porosity. We demonstrate that current methodological approaches are overestimating floc porosity by c. 30%. Conclusion: These new data have implications for our understanding of the controls on floc dynamics and the function of floc porosity and can improve the parameterisation of current cohesive sediment transport models. [ABSTRACT FROM AUTHOR]

Background and Purpose: The timely and accurate diagnosis of neuromyelitis optica spectrum disorder (NMOSD) is essential and exposure to multiple sclerosis (MS) disease‐modifying therapies may result in permanent neurological disability. Methods: Standardized 3‐Tesla 3‐dimensional brain MRI studies were retrospectively studied from people with NMOSD, MS, other CNS neurological diseases, and healthy control subjects. Comparisons of surface texture characteristics at the area postrema involving absolute introverted planar triangle counts, representing more complex and concave tissue topography, along with the spatial dissemination pattern of these triangles were performed cross‐sectionally and longitudinally. An ideal introverted planar triangle threshold separating groups with NMOSD and MS was accomplished using the highest Youden's J statistic. For the classification of NMOSD, out‐of‐sample and in‐sample measurements of the following were acquired: sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Results: The study cohort included 60 people with NMOSD, 100 people with MS, 12 with other neurological diseases, and five healthy controls. Significantly higher cross‐sectional median introverted triangle counts were observed when the NMOSD (median [interquartile range]: 100 [23.5]) group was compared to MS (65 [20.25]; p <.0001) and other neurological diseases (66 [13.75]; p <.0001). Distinct spatial dissemination patterns of triangles extending craniocaudally at the region of interest within the dorsal medulla was also seen between groups with NMOSD and MS (p <.0001). For the identification of NMOSD, out‐of‐sample sensitivity (83%), specificity (100%), PPV (100%), and NPV (60%) were achieved. Conclusions: Cross‐sectional and longitudinal dorsal medulla surface texture differences within selective regions of vulnerability differentiate NMOSD from MS. [ABSTRACT FROM AUTHOR]

With the increase of the adult orthodontic population, there is a need for an accurate and evidence-based prediction of the posttreatment face in 3 dimensions (3D). The objectives of this study are 1) to develop a 3D postorthodontic face prediction method based on a deep learning network using the patient-specific factors and orthodontic treatment conditions and 2) to validate the accuracy and clinical usability of the proposed method. Paired sets (n = 268) of pretreatment (T1) and posttreatment (T2) cone-beam computed tomography (CBCT) of adult patients were trained with a conditional generative adversarial network to generate 3D posttreatment facial data based on the patient's gender, age, and the changes of upper (ΔU1) and lower incisor position (ΔL1) as input. The accuracy was calculated with prediction error and mean absolute distances between real T2 (T2) and predicted T2 (PT2) near 6 perioral landmark regions, as well as percentage of prediction error less than 2 mm using test sets (n = 44). For qualitative evaluation, an online survey was conducted with experienced orthodontists as panels (n = 56). Overall, PT2 indicated similar 3D changes to the T2 face, with the most apparent changes simulated in the perioral regions. The mean prediction error was 1.2 ± 1.01 mm with 80.8% accuracy. More than 50% of the experienced orthodontists were unable to distinguish between real and predicted images. In this study, we proposed a valid 3D postorthodontic face prediction method by applying a deep learning algorithm trained with CBCT data sets. [ABSTRACT FROM AUTHOR]

Abstract Aims The current guidelines on pulmonary hypertension (PH) recommend the use of invasive examination for differentiating between left‐sided heart disease‐related (post‐capillary) and pre‐capillary PH. However, atrial sizes are considered markers of ventricular filling pressures. Therefore, we aimed to test the clinical applicability of atrial volumes measured by transthoracic three‐dimensional echocardiography (3DE) in differentiating between pre‐capillary and post‐capillary PH. Methods and results Seventy‐five consecutive patients with PH were prospectively examined with transthoracic 3DE. After less than 24 h, the patients underwent right heart catheterization and 3DE and were classified as pre‐capillary or post‐capillary PH according to the recommendations of the ESC guidelines. The atrial volumes were measured offline with dedicated commercial software. Thirty‐eight patients (13 men, age 65 ± 18 year) had pre‐capillary PH, and 37 (23 men, age 62 ± year) had post‐capillary PH. The mean pulmonary artery pressures were similar in patients with pre‐capillary and post‐capillary PH (38 [IQR 26, 54] mmHg vs. 41 [IQR 33, 48] mmHg, respectively, P = 0.49). The left atrial indexed maximum (LAVi max) and minimum (LAVi min) volumes were significantly larger in the post‐capillary PH patient group than in the pre‐capillary PH patient group (LAVi max: 64 ± 32 mL/m2 vs. 41 ± 25 mL/m2, P = 0.001; LAVi min: 50 ± 22 mL/m2 vs. 26 ± 24 mL/m2, P

Background and purpose: Differentiating between multiple sclerosis (MS) and small vessel disease (SVD) lesions represents a key challenge in the day-to-day management of patients. We aimed to distinguish between MS and SVD by identifying the dynamics of lesion movement patterns between enlarging and contracting foci from two MRI time points. Methods: Standardized 3-Tesla 3-dimensional brain magnetic resonance imaging (MRI) studies were performed at two time points on enrolled MS and SVD patients. Selected supratentorial lesions were segmented and longitudinal changes in the direction of lesion displacement and magnitude along with the evolution of contracting and expanding T1-weighted and T2-weighted MS lesions were quantified based on lesion centroid positioning. Bayesian linear mixed effects regression models were constructed to evaluate associations between changes in lesion transitions and disease state. Results: A total of 420 lesions were analyzed from 35 MS (female (F):22 (62.9%); median age (range):38 years (y) (22–61), median disease duration:7.38y (0.38–20.99)) and 12 SVD patients (F:11 (100%); 54y (40–66)). MS T2-weighted lesions that increased in volume between MRI time points demonstrated movement toward the cortex (p = 0.01), whereas those that decreased in volume moved toward the center (p < 0.0001). Lesion volume changes related to SVD demonstrated no effect on movement direction over time. Both expanding (p = 0.03) and contracting (p = 0.01) MS lesions demonstrated greater distances between centroids when compared to SVD. Conclusion: Lesion dynamics may reveal distinct characteristics associated with the biology of disease while providing further insights into the behavior of inflammatory CNS disorders. [ABSTRACT FROM AUTHOR]

Background: The uncemented collum femoris-preserving (CFP) stem offers preservation of the femoral neck and a more conservative soft tissue resection, which may facilitate a more normal walking pattern. We used gait analysis to evaluate if patients operated with a CFP stem showed more favourable hip kinematics and kinetics when compared with a group of patients operated with a conventional uncemented stem. Methods: 44 patients randomised to receive either a CFP or a Corail stem were studied and were operated using a direct lateral incision. Gait analysis was performed 2 years after the operation with a 12-camera motion capture system and 2 force plates. Hip kinematics and kinetics were analysed and 66 subjects served as controls. Results: None of the variables: speed, stride, cadence and stance showed any statistical significant difference between the 2 study groups. Neither did the hip kinematics and kinetics. Compared to controls, patients operated with the CFP stem showed an increased stance (62.5% vs. 61.1%, p < 0.006) and decreased hip abduction (-2.1° vs. -6.5°). Patients operated with the Corail stem showed decreased speed (1.18 vs. 1.23 m/second), and stride length (1.26 vs. 1.33 m), decreased hip extension (-7.5° vs. -12.8°) and range of hip flexion/extension (38° vs. 40.9°), as well as their hip adduction that was increased (6.3° vs. 4°), whereas their hip abduction was reduced (-2.8° vs. -6.5°), (p < 0.004) compared to the controls. Conclusions: Use of a CFP stem did not significantly influence any of the gait parameters studied when compared to a standard stem, but still both stems studied were associated with gait deviations when compared to controls. Whether these differences could be attributed to the stem used, the underlying hip disease, or both is still unknown. [ABSTRACT FROM AUTHOR]

Objective: Palatoplasty would involve the structures around the pterygoid hamulus. However, clinicians hold different opinions on the optimal approach for the muscles and palatine aponeurosis around the pterygoid hamulus. The absence of a consensus regarding this point can be attributed to the lack of investigations on the exact anatomy of this region. Therefore, we used micro-computed tomography to examine the anatomical structure of the region surrounding the pterygoid hamulus. Design: Cadaveric specimens were stained with iodine–potassium iodide and scanned by micro-computed tomography to study the structures of the tissues, particularly the muscle fibers. We imported Digital Imaging and Communications in Medicine images to Mimics to reconstruct a 3-dimensional model and simplified the model. Results: Three muscles were present around the pterygoid hamulus, namely the palatopharyngeus (PP), superior constrictor (SC), and tensor veli palatini (TVP). The hamulus connects these muscles as a key pivot. The TVP extended to the palatine aponeurosis, which bypassed the pterygoid hamulus, and linked the PP and SC. Some muscle fibers of the SC originated from the hamulus, the aponeurosis of which was wrapped around the hamulus. There was a distinct gap between the pterygoid hamulus and the palatine aponeurosis. This formed a pulley-like structure around the pterygoid hamulus. Conclusions: Transection or fracture of the palatine aponeurosis or pterygoid hamulus, respectively, may have detrimental effects on the muscles around the pterygoid hamulus, which play essential roles in the velopharyngeal function and middle ear ventilation. Currently, cleft palate repair has limited treatment options with proven successful outcomes. [ABSTRACT FROM AUTHOR]

We propose an open question that seeks to generalise the Four Colour Theorem from two to three dimensions. As an appetiser, we show that 12 instead of four colours are both sufficient and necessary to colour every 2-complex that embeds in a prescribed 3-manifold. However, our example of a 2-complex that requires 12 colours is not simplicial. [ABSTRACT FROM AUTHOR]

Avatar-based three-dimensional technology is a new approach to improve physical function in older adults. The aim of this study was to use three-dimensional video gaming technology in virtual reality training to improve postural balance and lower extremity strength in a population of community-dwelling older adults. The experimental group participated in the virtual reality training program for 60 min, twice a week, for 6 weeks. Both experimental and control groups were given three times for falls prevention education at the first, third, and fifth weeks. The experimental group showed significant improvements not only in static and dynamic postural balance but also lower extremity strength (p < .05). Furthermore, the experimental group was improved to overall parameters compared with the control group (p < .05). Therefore, three-dimensional video gaming technology might be beneficial for improving postural balance and lower extremity strength in community-dwelling older adults. [ABSTRACT FROM AUTHOR]

Summary: Three-dimensional (3D) bioprinting may overcome challenges in tissue engineering. Unlike conventional tissue engineering approaches, 3D bioprinting has a proven ability to support vascularization of larger scale constructs and has been used for several cardiovascular applications. An overview of 3D bioprinting techniques, in vivo translation, and challenges are described.

Background: The therapeutic IgG1 anti-CD20 antibody, rituximab (RTX), has greatly improved prognosis of many B-cell malignancies. Despite its success, resistance has been reported and detailed knowledge of RTX mechanisms are lacking. Complement-dependent cytotoxicity (CDC) is one important mode of action of RTX. The aim of this study was to systematically evaluate factors influencing complement-mediated tumor cell killing by RTX.Methods: Different RTX isotypes, IgG1, IgG3, IgA1 and IgA2 were evaluated and administered on four human CD20+ B-cell lymphoma cell lines, displaying diverse expression of CD20 and complement-regulatory protein CD59. Complement activation was assessed on lymphoma cells grown in 2 and 3-dimensional (3D) culture systems by trypan blue exclusion. CDC in 3D spheroids was additionally analyzed by Annexin V and propidium iodide staining by flow cytometry, and confocal imaging. Anti-CD59 antibody was used to evaluate influence of CD59 in RTX-mediated CDC responses. Statistical differences were determined by one-way ANOVA and Tukey post hoc test.Results: We found that 3 out of 4 lymphomas were sensitive to RTX-mediated CDC when cultured in 2D, while 2 out of 4 when grown in 3D. RTX-IgG3 had the greatest CDC potential, followed by clinical standard RTX-IgG1 and RTX-IgA2, whereas RTX-IgA1 displayed no complement activation. Although the pattern of different RTX isotypes to induce CDC were similar in the sensitive lymphomas, the degree of cell killing differed. A greater CDC activity was seen in lymphoma cells with a higher CD20/CD59 expression ratio. These lymphomas were also sensitive to RTX when grown in 3D spheroids, although the CDC activity was substantially reduced compared to 2D cultures. Analysis of RTX-treated spheroids demonstrated apoptosis and necrosis essentially in the outer cell-layers. Neutralization of CD59 overcame resistance to RTX-mediated CDC in 2D-cultured lymphoma cells, but not in spheroids.Conclusions: The results demonstrate that CDC outcome in CD20+ B-cell lymphoma is synergistically influenced by choice of RTX isotype, antigen density, tumor structure, and degree of CD59 expression. Assessment of tumor signatures, such as CD20/CD59 ratio, can be advantageous to predict CDC efficiency of RTX in vivo and may help to develop rational mAbs to raise response rates in patients. [ABSTRACT FROM AUTHOR]

The Goutallier and Warner Classification systems are useful in determining rotator cuff reparability. Data are limited on how accurately the scapular-Y view used in both systems reflects the 3-dimensional (3-D) changes in fatty infiltration (FI) and muscle atrophy (MA). Tendon retraction in the setting of a cuff tear may also influence the perception of these changes. This study's objectives were to (1) measure the 3-D volume of the supraspinatus muscle in intact rotator cuffs, and with varying magnitudes of retraction; (2) measure the 3-D volume of FI in the supraspinatus muscle in these conditions; and (3) determine the influence of tendon retraction on measured FI and MA using the Goutallier and Warner Classification Systems. Between August 2015 and February 2016, all shoulder magnetic resonance images (MRIs) at the Portland VA Medical Center were standardized to include the medial scapular border. MRIs and charts were reviewed for inclusion/exclusion criteria. Included MRIs were categorized into 4 groups based on rotator cuff retraction. Supraspinatus muscle and fossa were traced to create 3-D volumes. FI and MA were measured within the supraspinatus. The supraspinatus muscle was graded among 6 physicians using the Goutallier and Warner classification systems. These grades were compared to 3-D measured FI and MA. The influence of tendon retraction on the measured grades were also evaluated. One hundred nine patients met inclusion/exclusion criteria. Ten MRIs for each group (N = 40) were included for image analysis. Supraspinatus volume tracings were highly reproducible and consistent between tracers. Supraspinatus muscle volumes decreased while global FI and MA increased with greater degrees of tendon retraction. In muscles with less than 10% global fat, fat concentrated in the lateral third of the muscle. In muscle with more than 10% global fat content, it distributed more diffusely throughout the muscle from medial to lateral. In comparing the scapular-Y to a medial cut, there was no consistent trend in FI whereas MA was more accurate at the medial cut. Parasagittal imaging location did not significantly influence the Goutallier score; however, assessment of MA using the Warner score leads readers to perceive less MA medially regardless of the magnitude of tendon retraction. The pattern of FI within the supraspinatus muscle changes from a laterally based location around the muscle-tendon junction to a more diffuse, global infiltration pattern when the whole muscle fat content exceeds 10%. [ABSTRACT FROM AUTHOR]

The present studies were conducted to evaluate key serum proteins and other components that mediate anchorage-independent growth (3-D growth) of LNCaP prostate cancer cells as spheroids. The cells were cultured on ultra-low attachment plates in the absence and presence of fetuin-A and with or without extracellular vesicles. The data show that fetuin-A (alpha 2HS glycoprotein) is the serum protein that mediates 3-D growth in these cells. It does so by sequestering extracellular vesicles of various sizes on the surfaces of rounded cells that grow as spheroids. These vesicles in turn transmit growth signals such as the activation of AKT and MAP kinases in a pattern that differs from the activation of these key growth signaling pathways in adherent and spread cells growing in 2-D. In the process of orchestrating the movement and disposition of extracellular vesicles on these cells, fetuin-A is readily internalized in adhered and spread cells but remains on the surfaces of non-adherent cells. Taken together, our studies suggest the presence of distinct signaling domains or scaffolding platforms on the surfaces of prostate tumor cells growing in 3-D compared to 2-D. [ABSTRACT FROM AUTHOR]

Abstract Background The use of 3-dimensional (3D) endoscopic thyroidectomy (ET) has been increasing, but its feasibility and safety have not been well documented for thyroidectomy. Hence, to systematically investigate the comparative outcomes during 3D-ET and 2-dimensional (2D) ET for benign and malignant lesions, we conducted this meta-analysis. Methods Based on the PRISMA guidelines, a systematic database search of the PubMed, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), and Chinese Wanfang databases was performed. The eligible studies were published in English and Chinese up to October 2020. The major endpoints evaluated were procedure time, blood loss, postoperative drainage, postoperative hospitalization, postoperative complications, total number of lymph node dissections (LNDs), and total cost. Results A total of 15 relevant studies including 1190 patients (583 for 3D-ET and 607 for 2D-ET) compared the application of 3D and 2D laparoscopic systems in thyroid surgery, of which 8 were endoscopic benign thyroidectomy (EBT) and 7 were endoscopic malignant thyroidectomy (EMT). Our meta-analysis indicated that 3D-ET generally had advantages over 2D-ET in terms of procedure time (P = 0.000), blood loss (P = 0.000), postoperative drainage (P = 0.000), postoperative complications (P = 0.000), and LNDs (P = 0.006). However, there were no significant differences between the two systems in terms of total cost (P = 0.245) or postoperative hospitalization (P = 0.068). Subgroup analysis showed consistency of the overall outcomes in each subset, but a shorter postoperative hospitalization in 3D-EBT was revealed. Conclusions Compared to 2D-ET, 3D endoscopic thyroidectomy is an efficient, safe, and reliable method with better depth perception and stereoscopic vision, and an equally satisfactory outcome. More clinical RCTs with long-term follow-up are required to reproduce these promising results.

Understanding the role of autophagy in cancer has been limited by the inability to measure this dynamic process in formalin-fixed tissue. We considered that 3-dimensional models including ex vivo tumor, such as we have developed for studying mesothelioma, would provide valuable insights. Using these models, in which we could use lysosomal inhibitors to measure the autophagic flux, we sought a marker of autophagy that would be valid in formalin-fixed tumor and be used to assess the role of autophagy in patient outcome. Autophagy was studied in mesothelioma cell lines, as 2-dimensional (2D) monolayers and 3-dimensional (3D) multicellular spheroids (MCS), and in tumor from 25 chemonaive patients, both as ex vivo 3D tumor fragment spheroids (TFS) and as formalin-fixed tissue. Autophagy was evaluated as autophagic flux by detection of the accumulation of LC3 after lysosomal inhibition and as autophagy initiation by detection of ATG13 puncta. We found that autophagic flux in 3D, but not in 2D, correlated with ATG13 positivity. In each TFS, ATG13 positivity was similar to that of the original tumor. When tested in tissue microarrays of 109 chemonaive patients, higher ATG13 positivity correlated with better prognosis and provided information independent of known prognostic factors. Our results show that ATG13 is a static marker of the autophagic flux in 3D models of mesothelioma and may also reflect autophagy levels in formalin-fixed tumor. If confirmed, this marker would represent a novel prognostic factor for mesothelioma, supporting the notion that autophagy plays an important role in this cancer.

Exoscopic surgery promises alleviation of physical strain, improved intraoperative visualization and facilitation of the clinical workflow. In this prospective observational study, we investigate the clinical usability of a novel 3D4K-exoscope in routine neurosurgical interventions. Questionnaires on the use of the exoscope were carried out. Exemplary cases were additionally video-documented. All participating neurosurgeons (n = 10) received initial device training. Changing to a conventional microscope was possible at all times. A linear mixed model was used to analyse the impact of time on the switchover rate. For further analysis, we dichotomized the surgeons in a frequent (n = 1) and an infrequent (n = 9) user group. A one-sample Wilcoxon signed rank test was used to evaluate, if the number of surgeries differed between the two groups. Thirty-nine operations were included. No intraoperative complications occurred. In 69.2% of the procedures, the surgeon switched to the conventional microscope. While during the first half of the study the conversion rate was 90%, it decreased to 52.6% in the second half (p = 0.003). The number of interventions between the frequent and the infrequent user group differed significantly (p = 0.007). Main reasons for switching to ocular-based surgery were impaired hand–eye coordination and poor depth perception. The exoscope investigated in this study can be easily integrated in established neurosurgical workflows. Surgical ergonomics improved compared to standard microsurgical setups. Excellent image quality and precise control of the camera added to overall user satisfaction. For experienced surgeons, the incentive to switch from ocular-based to exoscopic surgery greatly varies. [ABSTRACT FROM AUTHOR]

Transcatheter therapies to treat tricuspid regurgitation are being developed, but few have attempted the gold standard of surgical repair: ring annuloplasty. We describe the first-ever fully percutaneous implantation of a circumferential, semirigid annuloplasty ring to treat massive secondary tricuspid regurgitation. (Level of Difficulty: Advanced.)

Abstract Background Intraoperative 3-dimensional (3D) navigation is increasingly being used for pedicle screw placement. For this purpose, dedicated mobile 3D C-arms are capable of providing intraoperative fluoroscopy-based 3D image data sets. Modern 3D C-arms have a large field of view, which suggests a higher radiation exposure. In this experimental study we therefore investigate the radiation exposure of a new mobile 3D C-arm with large flat-panel detector to a previously reported device with regular flat-panel detector on an Alderson phantom. Methods We measured the radiation exposure of the Vision RFD 3D (large 30 × 30 cm detector) while creating 3D image sets as well as standard fluoroscopic images of the cervical and lumbar spine using an Alderson phantom. The dosemeter readings were then compared with the radiation exposure of the previous model Vision FD Vario 3D (smaller 20 × 20 cm detector), which had been examined identically in advance and published elsewhere. Results The larger 3D C-arm induced lower radiation exposures at all dosemeter sites in cervical 3D scans as well as at the sites of eye lenses and thyroid gland in lumbar 3D scans. At ​​male and especially female gonads in lumbar 3D scans, however, the larger 3D C-arm showed higher radiation exposures compared with the smaller 3D C-arm. In lumbar fluoroscopic images, the dosemeters near/in the radiation field measured a higher radiation exposure using the larger 3D C-arm. Conclusions The larger 3D C-arm offers the possibility to reduce radiation exposures for specific applications despite its larger flat-panel detector with a larger field of view. However, due to the considerably higher radiation exposure of the larger 3D C-arm during lumbar 3D scans, the smaller 3D C-arm is to be recommended for short-distance instrumentations (mono- and bilevel) from a radiation protection point of view. The larger 3D C-arm with its enlarged 3D image set might be used for long instrumentations of the lumbar spine. From a radiation protection perspective, the use of the respective 3D C-arm should be based on the presented data and the respective application.

Abstract Background This study aimed to investigate dental student’s perception of facial attractiveness with regard to different combinations of anteroposterior malar-jaw positions using 3-dimensional (3-D) reconstructed images of subjects. Methods Two Chinese young adults (1 male and 1 female) with straight profiles and average malar projections were selected for the study. 3-D facial images and cone-beam computed tomography images of these two subjects were superimposed using 3-D imaging software. Lateral and oblique views of nine different images were created by moving the maxillomandibular complex and/or zygomatic bone by 4 mm either forward or backward along the sagittal plane. One hundred three undergraduate dental students (n = 24, 33, and 46 students from the Year 3, 4, and 5, respectively) then scored lateral and 45° oblique view images of the newly reconstructed faces. Results In the present study, images with a neutral malar and retruded jaws were found to be the most attractive in both male and female subjects. In addition, the Protruded malar (PM) group (p

BackgroundAdvances in digital imaging including evolving of 3-dimensional (3D) exoscope has allowed its use as an alternative to microscopes in neurosurgery. The exoscope can concede wide space around the operating table and patient. Here, we show a three-surgeon–six-hand operative approach using a 4K-3D exoscope. Practical advantages and disadvantages of this approach are discussed.Clinical PresentationA 58-year-old male was refered with a 60 mm diameter meningioma in the right frontal convexity. The tumor removal was done by an operator and two assistants with a scrub nurse while viewing images displayed on a 55-inch monitor with integrated 4K and 3D visualization technology retrieved by KINEVO®. Meaningful communication between the operator and two assistants allowed for simultaneous, and precise surgical procedures. Gross total removal was achieved without damaging the brain.ConclusionThe ocular-free, openness of 4K-3D exoscope allows for a three-surgeon–six-handed operation, which leads to simultaneous surgical maneuvers by multiple hands, shorter operative time, flexible/intermittent brain retraction made by two assistants, and educational benefits owing to the surgical procedure being visually shared.

Elbow derangements are common. Clinical examination is supplemented by magnetic resonance imaging (MRI) for optimal diagnostic assessment of such disorders. 3-dimensional (3D) imaging is feasible on newer MR scanners in acceptable acquisition times. Isotropic high-resolution 3D MRI affords multiplanar reconstructions and aids in diagnostic evaluation of elbow disorders and pre-/post-surgical assessments. The article details technical considerations of 3D elbow MRI and discusses its role in diagnostic evaluation of elbow disorders with relevant comparisons to 2D MRI and emphasizes as to how such advanced imaging assists in pre- and post-surgical assessments of tendon and ligament derangements.

Objectives: The aim of this study was to identify cone-beam computed tomography (CBCT) protocols that offer an optimal balance between effective dose (ED) and 3D model for orthognathic virtual surgery planning, using CT as a reference, and to assess whether such protocols can be defined based on technical image quality metrics., Methods: Eleven CBCT (VISO G7, Planmeca Oy, Helsinki, Finland) scan protocols were selected out of 32 candidate protocols, based on ED and technical image quality measurements. Next, an anthropomorphic RANDO SK150 phantom was scanned using these 11 CBCT protocols and 2 CT scanners for bone quantity assessments. The resulting DICOM (Digital Imaging and Communications in Medicine) files were converted into Standard Tessellation Language (STL) models that were used for bone volume and area measurements in the predefined orbital region to assess the validity of each CBCT protocol for virtual surgical planning., Results: The highest CBCT bone volume and area of the STL models were obtained using normal dose protocol (F2) and ultra-low dose protocol (J13), which resulted in 48% and 96% of the mean STL bone volume and 48% and 95% of the bone area measured on CT scanners, respectively., Conclusions: The normal dose CBCT protocol "F2" offered optimal bone area and volume balance for STL. The optimal CBCT protocol can be defined using contrast-to-noise ratio and modulation transfer function values that were similar to those of the reference CT scanners'. CBCT scanners with selected protocols can offer a viable alternative to CT scanners for acquiring STL models for virtual surgical planning at a lower effective dose., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology and the International Association of Dentomaxillofacial Radiology.)