Search Results (735)

Background and Clinical Significance: Preoperative planning is crucial for improving surgical safety and outcomes, particularly in minimally invasive surgery, where tactile feedback is absent. Three-dimensional (3D) printing offers patient-specific anatomical models that can enhance surgical planning. Its application in diverticular disease remains underexplored. Case Presentation: We present the case of a 65-year-old male with recurrent diverticulitis involving the sigmoid and descending colon. After conservative management of an acute episode, preoperative imaging revealed extensive diverticulosis. A patient-specific 3D-printed model was created from CT images to plan the surgical approach. The model helped determine the need for a left hemicolectomy rather than a simple sigmoidectomy, anticipated technical challenges such as lowering the left colic flexure and ligating the inferior mesenteric artery, and improved patient counseling. The surgery was performed laparoscopically without complications, and the patient was discharged on postoperative day six. Histology confirmed diverticulosis with perivisceritis and reactive lymphadenitis. Conclusions: This case demonstrates the potential of 3D printing to optimize surgical planning in diverticular disease, enabling tailored resections and improving operative strategy. Broader adoption may be limited by time and cost but offers clear educational and clinical benefits. Full article

Investigating the pore structure and understanding the relationship between pore characteristics and mechanical properties are crucial to research in the study of cement mortar. At present, the segmentation of large-scale concrete pores is mainly conducted using traditional algorithms or software, which are time-consuming and operate in a semi-automated manner. However, the application of these methods faces challenges when analyzing large-scale rock pores due to factors such as a lack of data, artifacts, and inconsistent contrast. In this study, six series of cement mortars were subjected to real-time CT scanning under uniaxial loading (RT-CT) to collect real-time three-dimensional data on the evolution of pore structures during loading. To address issues such as artifacts and inconsistent contrast, a new augmentation method was proposed to overcome artifacts and enhance contrast consistency. Finally, the augmented dataset was utilized for training, and the Fast R-CNN algorithm served as the framework for developing the pore recognition model. The results indicate that the improved algorithm demonstrates enhanced convergence and greater accuracy in pore segmentation. A mathematical model is developed to relate uniaxial compressive strength (UCS) to pore fractal dimension and porosity, based on pore segmentation analysis. The fractal dimensions evolution of each specimen is consistent with the progressive failure indicated by the strain-stress curve. Under uniaxial loading, specimens with a 4:1 cement–sand ratio exhibited peak strength. The incorporation of fractals improved particle contact, thereby facilitating the formation of the skeletal structure. These efforts contribute to improving the identification of the deformation of cement mortars. Full article

Orbital floor fractures are primarily caused by blunt trauma to the area around the eyes. These injuries most commonly affect the orbital floor and medial wall due to the fragility of these structures. The mechanism typically involves transmission of force through the orbital rim or an acute increase in intraorbital pressure caused by globe displacement. Blowout fractures often occur alongside additional maxillofacial fractures and periorbital soft tissue injuries. The reported causes mirror those of general maxillofacial trauma and include motor vehicle collisions, interpersonal violence, falls, sports-related injuries, incidents involving firearms, and occupational accidents. Here, we present the case of a 56-year-old male patient who sustained an exceptionally rare injury pattern characterized by a complete orbital floor fracture with globe dislocation into the maxillary sinus. Such extensive fractures are associated with significant functional impairments, including diplopia, enophthalmos, and restricted extraocular muscle movement, as well as marked aesthetic deformity. Comprehensive diagnostic imaging, comprising coronal, sagittal, and three-dimensional CT reconstructions, was crucial for accurately assessing the extent of bony disruption and soft tissue involvement. Particular emphasis should be placed on imaging that clearly delineates the extraocular muscles and the optic nerve, as precise evaluation of these structures is essential for surgical planning and prognosis. Surgical management involved repositioning of the globe and the orbital contents, followed by reconstruction of the orbital floor using a titanium mesh anchored to the infraorbital rim. This case highlights the technical challenges of total orbital floor reconstruction, emphasizing the importance of meticulous anatomical restoration for achieving optimal functional and aesthetic outcomes. Full article

Computer-assisted surgery (CAS) and virtual surgical planning (VSP) have transformed jaw reconstruction, allowing immediate insertion of dental implants during surgery for better rehabilitation of occlusal function. However, traditional planning for optimal location and angulation of dental implants and fibula relies on experience and can be time-consuming. This study aimed to propose a function-driven workflow and develop an automatic computer program for optimal positioning of simultaneous dental implants and fibula segments. A customized computer program was developed using MATLAB. Computed tomography (CT) of the lower limbs of ninety-one Southern Chinese individuals was retrieved and cross-sections of three-dimensional (3D) fibula models were comprehensively investigated for implant installation. Our research proves that the accuracy of the program in identifying the anatomical orientation of the fibula was 92%. The ideal location, angulation and length of implant could be automatically generated based on any selected implant diameter, with a surgical feasibility of 94%. To the best of our knowledge, this is the first study to develop and validate a customized automatic computer program for osseointegrated implant design in fibula flap surgery. This program can be incorporated into the current workflow of CAS to further the development of reliable and efficient surgical planning for function-driven jaw reconstruction. Full article

Objectives: The present study aimed to determine the growth dynamics of the ossification centers of the twelfth thoracic vertebra in the human fetus, focusing on detailed linear, surface, and volumetric parameters of both the vertebral body and neural processes. Methods: The investigation was based on 55 human fetuses (27 males, 28 females) aged 17–30 weeks of gestation. High-resolution low-dose computed tomography, three-dimensional reconstruction, digital image analysis and appropriate statistical modeling were used to obtain detailed morphometric measurements. Results: All measured morphometric parameters of the Th12 vertebral body ossification center—transverse and sagittal diameters, cross-sectional area, and volume—increased linearly with gestational age (R² = 0.94–0.97). A similar linear growth pattern was demonstrated for the length, width, cross-sectional area, and volume of the right and left neural process ossification centers (R² = 0.97–0.98). No statistically significant sex-related or side-related differences were found, allowing the establishment of single normative growth curves for each parameter. Conclusions: This study provides the first comprehensive CT-based normative data for the ossification centers of the fetal Th12 vertebra in the second and early third trimesters. The presented linear growth models and reference values may assist anatomists, radiologists, obstetricians, and pediatric spine surgeons in estimating fetal age, and in the prenatal and postnatal assessment of congenital spinal anomalies, especially at the thoracolumbar junction. Further research on larger and broader gestational cohorts is warranted to validate and extend these findings. Full article

Background and Objectives: Liver fibrosis is the key prognostic factor in patients with chronic liver diseases (CLD). Computed tomography (CT) is widely used in clinical practice, but it has limited value in assessing liver fibrosis in precirrhotic stages. Quantitative CT analysis based on radiomics can provide additional information by extracting hidden image patterns, but the optimal approach remains to be determined. The aims of this study were to evaluate automated CT-based radiomic models for predicting biopsy-proven liver fibrosis, to compare different segmentation strategies and organ inclusions approaches, and to assess its performance against vibration-controlled transient elastography (VCTE). We also examined whether these models could predict liver steatosis. Methods: In this retrospective study, 58 patients with biopsy-proven CLD and 9 controls underwent VCTE and contrast-enhanced abdominal CT within three months of biopsy. Radiomic features were extracted from portal-venous-phase images using both two-dimensional (2D) and three-dimensional (3D) segmentations of the liver, spleen, and combined liver–spleen. Multilayer perceptron neural (MLP) networks were trained to predict fibrosis staging (≥F1, ≥F2, ≥F3, and F4) and steatosis grading (≥S1, ≥S2, and S3). Model performance was assessed using area under the receiver operating characteristic curve (AUROC) and accuracy. Results: The 3D radiomic models outperformed 2D models in predicting liver fibrosis stages. In the 3D radiomic model category, the combined 3D liver–spleen model achieved very good to excellent performance (AUROCs 0.974, 0.929, 0.928, and 0.898, respectively, for ≥F1, ≥F2, ≥F3, and F4), with comparable results to VCTE (AUROCs 0.921, 0.957, 0.968, and 0.909, respectively, for ≥F1, ≥F2, ≥F3, and F4). Radiomic models showed poor predictive ability for steatosis grades (AUROCs 0.44–0.69) compared to controlled attenuation parameter (CAP) (AUROCs 0.798–0.917). Conclusions: CT-based radiomic models showed potential for predicting liver fibrosis stage. The 3D model of liver and spleen had the highest performance, comparable to VCTE. This approach could be valuable in clinical settings where elastography is unavailable or inconclusive and for opportunistic screening in patients already undergoing CT for other medical indications. In contrast, portal-venous-phase radiomics lacked predictive value for steatosis assessment. Larger, multicenter studies are required to validate these results. Full article

This study presents a three-dimensional finite element (FE) analysis of the human foot bone structure under mid-stance loading during race walking. A subject-specific biomodel comprising 26 bones and over 40 ligaments was reconstructed from computed tomography (CT) data using Materialise Mimics Research 21.0 and 3-Matic Research 13.0, and subsequently analyzed in ANSYS Workbench 2024 R1. The model included explicit cortical, trabecular, and ligamentous volumes, each assigned linear-elastic, isotropic material properties based on biomechanical literature data. Boundary conditions simulated the mid-stance phase of race walking, applying a distributed plantar pressure of 0.25 MPa over the metatarsal and phalangeal regions. Numerical simulations yielded maximum total displacements of 0.00018 mm, maximum von Mises stresses of 0.171 MPa, and maximum strains of 2.5 × 10⁻⁵, all remaining well within the elastic range of bone tissue. The results confirm the model’s numerical stability, geometric fidelity, and capacity to represent physiologically realistic loading responses. The developed framework demonstrates the potential of high-resolution, image-based finite element modelling for investigating stress–strain patterns of the foot during athletic gait, and establishes a reproducible reference for future analyses involving pathological gait, orthotic optimisation, and musculoskeletal load assessment in sports biomechanics. Full article

Background: Jones fractures of the 5th metatarsal are frequently associated with nonunion due to limited vascularization and repetitive mechanical stress. The aim of the study was to compare the biomechanical performance of T-plate and bicortical screw fixation using standardized 3D models. Methods: Three-dimensional models of the 5th metatarsal were generated from CT images and printed using PolyJet technology (Stratasys J5 DentaJet) using a rigid-elastic composite with properties similar to cortical and cancellous bone. Jones fractures were fixed with either a locked T-plate or a bicortical screw. The samples were tested under axial and oblique static loads (α = 0°, 90°, 180°) and for three values of interfragmentary distance (d = 0.1–1 mm), in a 3 × 2 factorial design. Results: The T-plate fixation recorded a maximum yield force (Fmax) of 149.78 ± 8.53 N (138–161 N), significantly higher compared to the bicortical screw −98.56 ± 2.58 N (96–101 N), (p < 0.05). The ductility index was higher for the plate, indicating a progressive transition to yield. The α and d factors significantly influenced the mechanical behavior, with the polynomial model explaining over 95% of the total variation. Discussion: The plate fixation demonstrated greater strength and superior biomechanical tolerance in imperfect reduction scenarios. The main limitation is the lack of fatigue testing and the inability of 3D models to reproduce the structural heterogeneity of human bone. Conclusions: Implant selection should be individualized based on fracture stability. 3D models provide a reproducible platform for comparative evaluation of osteosynthesis methods, but future studies should include cyclic loading and biological validation. Full article

In high-voltage direct-current (HVDC) transmission and large-scale power-system operation, DC-bias effects can drive current-transformer (CT) cores into premature saturation, distorting the secondary current and seriously jeopardizing the reliability of protective relaying and metering. To address the limited fitting capability and robustness of conventional compensation approaches in the presence of nonlinear distortion, this paper proposes a convolutional neural network (CNN)-based inversion method for CT saturation current. First, a simulation model is built on the PSCAD/EMTDC platform to generate a dataset of saturated, distorted currents covering DC components from −50 A to +50 A. Then, a CNN with a three-layer one-dimensional convolutional architecture is designed; leveraging local convolutions and parameter sharing, it extracts features from current sequences and reconstructs the true primary current. Simulation results show that the proposed method accurately recovers the primary-current waveform under mild-to-severe saturation, with errors within 2%, and exhibits strong adaptability and robustness with respect to both the polarity and magnitude of the DC component. These findings verify the effectiveness of CNNs for CT-saturation compensation. Full article

Three-dimensional medical images, such as those obtained from MRI scans, offer a comprehensive view that aids in understanding complex shapes and abnormalities better than 2D images, such as X-ray, mammogram, ultrasound, and 2D CT slices. However, MRI machines are often inaccessible in certain regions due to their high cost, space and infrastructure requirements, a lack of skilled technicians, and safety concerns regarding metal implants. A viable alternative is generating 3D images from 2D scans, which can enhance medical analysis and diagnosis and also offer earlier detection of tumors and other abnormalities. This systematic review is focused on Generative Adversarial Networks (GANs) for 3D medical image analysis over the last three years, due to their dominant role in 3D medical imaging, offering unparalleled flexibility and adaptability for volumetric medical data, as compared to other generative models. GANs offer a promising solution by generating high-quality synthetic medical images, even with limited data, improving disease detection and classification. The existing surveys do not offer an up-to-date overview of the use of GANs in 3D medical imaging. This systematic review focuses on advancements in GAN technology for 3D medical imaging, analyzing studies, particularly from the recent years 2022–2025, and exploring applications, datasets, methods, algorithms, challenges, and outcomes. It affords particular focus to the modern GAN architectures, datasets, and codes that can be used for 3D medical imaging tasks, so readers looking to use GANs in their research could use this review to help them design their study. Based on PRISMA standards, five scientific databases were searched, including IEEE, Scopus, PubMed, Google Scholar, and Science Direct. A total of 1530 papers were retrieved on the basis of the inclusion criteria. The exclusion criteria were then applied, and after screening the title, abstract, and full-text volume, a total of 56 papers were extracted from these, which were then carefully studied. An overview of the various datasets that are used in 3D medical imaging is also presented. This paper concludes with a discussion of possible future work in this area. Full article

The pore structure of cocopeat-based substrates critically influences their hydraulic properties, directly affecting water use efficiency in soilless cultivation systems. Previous macroscopic modeling approaches infer pore structures indirectly from water retention curves and rely on empirical parameterization of pore geometry and connectivity, overlooking microscale features that directly control fluid pathways and permeability. To address this gap, this study employed micro-CT imaging to reconstruct the three-dimensional pore structures of coarse cocopeat and a fine cocopeat–perlite mixture. Nine regions of interest (ROIs), representing three typical pore types in each substrate, were selected for quantitative pore structure analysis and pore-scale saturated flow simulations. Results show that over 90% of pore diameters in both substrates fall within the 0–400 μm range, and variations in cocopeat particle size and perlite addition significantly affect average pore diameter, porosity, fractal dimension, and tortuosity, thereby influencing permeability and local flow distribution. This study provides new insights into the microscale mechanisms governing water movement in cocopeat-based substrates and reveals key structural factors regulating hydraulic behavior in soilless cultivation systems. Full article

During the calcination of petroleum coke in a vertical shaft calciner, the particle packing structure exerts a decisive influence on the bed resistance characteristics and further significantly affects the devolatilization efficiency. This study employs three-dimensional computed tomography (CT) scanning technology to digitally reconstruct the pore structure of a packed bed of petroleum coke particles. Moreover, a computational fluid dynamics (CFD) simulation model is developed to simulate gas flow at the pore scale within the packed bed. A systematic analysis is conducted on the influence mechanisms of various factors, including particle size, gas velocity, gas composition, temperature, and bed length, on the gas flow resistance characteristics within the bed. The research findings indicate that the porosity of the packed beds of petroleum coke particles with different sizes ranges from 38.7% to 52%. The pore size within the bed exhibits a positive correlation with particle size, and gas migration predominantly occurs through slit flow. Under identical inlet gas velocity conditions, smaller particle sizes result in higher maximum gas velocities and greater unit pressure drops within the bed. At low gas velocities (e.g., 0.01–0.06 m/s in this work), both the maximum gas velocity and maximum pore pressure demonstrate a significant linear increase. The various factors exhibit different degrees of influence on the unit pressure drop, with particle size having the most significant impact, followed by gas velocity, then temperature, and finally gas composition. Consequently, the relevant research findings provide crucial theoretical support for optimizing the calcination process in vertical shaft calciners, expanding the range of raw material adaptability, and reducing production energy consumption. Full article

Femoroacetabular impingement (FAI) and hip dysplasia have been shown to increase the risk of hip osteoarthritis in affected individuals. MRI with T2 mapping provides an objective measure of femoral and acetabular articular cartilage tissue quality. This study aims to evaluate the relationship between hip morphology measurements collected from three-dimensional (3D) reconstructed computed tomography (CT) scans and the T2 mapping values of hip articular cartilage assessed by three independent, blinded reviewers on the optimal sagittal cut. Hip morphology measures including lateral center edge angle (LCEA), acetabular version, Tönnis angle, acetabular coverage, alpha angle, femoral torsion, neck-shaft angle (FNSA), and combined version were recorded from preoperative CT scans. The relationship between T2 values and hip morphology was assessed using univariate linear mixed models with random effects for individual patients. Significant associations were observed between femoral and acetabular articular cartilage T2 values and all hip morphology measures except femoral torsion. Hip morphology measurements consistent with dysplastic anatomy including decreased LCEA, increased Tönnis angle, and decreased acetabular coverage were associated with increased cartilage damage (p < 0.001 for all). Articular cartilage T2 values were strongly associated with the radiographic markers of hip dysplasia, suggesting hip microinstability significantly contributes to cartilage damage. The relationships between hip morphology measurements and T2 values were similar for the femoral and acetabular sides, indicating that damage to both surfaces is comparable rather than preferentially affecting one side. Full article

A six-year-old, neutered male Pomeranian weighing 4.25 kg was presented with a two-year history of non-weight-bearing lameness of the left thoracic limb following an untreated traumatic olecranon fracture. Orthopedic examination revealed markedly reduced elbow joint range of motion and muscle atrophy. Radiographs demonstrated a distinct fracture line with proximolateral displacement of the olecranon fragment. Preoperative computed tomography (CT) and three-dimensional (3D) reconstruction were used to establish the surgical plan and to pre-contour a locking plate. Surgical treatment was performed in sequential steps, including removal of scar tissue, reopening of the bone marrow channel, and internal fixation. Considering the compromised biological environment of a chronic non-union, a bioactive graft composed of porous leaf-stacked structure (LSS) polycaprolactone particles incorporating recombinant human bone morphogenetic protein-2 (rhBMP-2) and mesenchymal stem cells (MSCs) was applied in combination with plate-screw fixation. The patient showed progressive improvement after surgery, achieving full weight-bearing and restoration of elbow joint motion comparable to the contralateral side. Follow-up radiographs and CT confirmed fracture union, and the radiolucency of the LSS scaffold enabled precise monitoring of bone healing. This case highlights the potential utility of combining patient-specific surgical planning with sustained delivery of rhBMP-2 and MSCs using LSS particles for the management of chronic non-union fractures in small animals. Full article

Background and Objectives: Femoroacetabular impingement (FAI) morphology refers to structural abnormalities that can alter normal joint mechanics and potentially lead to early onset osteoarthritis. Although commonly diagnosed in symptomatic individuals, such morphological features are also found in asymptomatic adults, underlining their relevance for early detection and preventive management. This study aimed to evaluate the three-dimensional congruence of hip joint surfaces in relation to FAI and the morphology of asymptomatic hips with potential FAI features. Materials and Methods: Retrospective three-dimensional reconstructions of 86 hip joints were created using Mimics software from computed tomography (CT) scans of the lower abdomen and pelvis retrieved from the radiology archive. CT scans belonged to individuals with preserved anatomical integrity (20 females, 23 males, bilateral hips), aged 24–76 years. Lateral center-edge angle (LCEA) and alpha angle measurements were obtained from reconstructions to assess the risk of asymptomatic FAI. Results: Significant gender differences were found in alpha angles. The mean right alpha angle was 46.57 ± 3.12° in females and 49.28 ± 6.66° in males p = 0.046, while the mean left alpha angle was 43.75 ± 5.53° in females and 47.37 ± 5.77° in males p = 0.021. An alpha angle >50°, suggestive of cam type FAI, was present in 25.6% of right hips and 13.9% of left hips. LCEA values showed no significant gender or side differences, with a mean of 30.21 ± 8.96° across the cohort. Conclusions: Three-dimensional evaluation of asymptomatic hips revealed FAI-consistent morphology in a notable proportion of individuals, particularly males. Cam-type deformities tended to occur bilaterally, whereas pincer-type morphologies were more sporadic and often unilateral. Increased alpha and LCEA measurements in asymptomatic individuals suggest that FAI morphology may exist subclinically without always indicating disease. Future studies incorporating longitudinal imaging and clinical follow-up are needed to clarify the prognostic significance of these findings. Full article