Search Results (328)

As a critical parameter for describing oil–water two-phase flow behavior, relative permeability curves are widely applied in field development, dynamic forecasting, and reservoir numerical simulation. This study addresses the issue of relative permeability anisotropy, focusing on the seepage characteristics of two typical bedding structures in sandstone reservoirs—tabular cross-bedding and parallel bedding—through multi-directional displacement experiments. A novel anisotropic relative permeability testing apparatus was employed to conduct displacement experiments on cubic core samples, comparing the performance of the explicit Johnson–Bossler–Naumann (JBN) method, based on Buckley–Leverett theory, with the implicit Automatic History Matching (AHM) method, which demonstrated superior accuracy. The results indicate that displacement direction significantly influences seepage efficiency. For cross-bedded cores, displacement perpendicular to bedding (Z-direction) achieved the highest displacement efficiency (75.09%) and the lowest residual oil saturation (22%), primarily due to uniform fluid distribution and efficient pore utilization. In contrast, horizontal displacement exhibited lower efficiency and higher residual oil saturation due to preferential flow path effects. In parallel-bedded cores, vertical displacement improved efficiency by 18.06%, approaching ideal piston-like displacement. Microscale analysis using Nuclear Magnetic Resonance (NMR) and Computed Tomography (CT) scanning further revealed that vertical displacement effectively reduces capillary resistance and promotes uniform fluid distribution, thereby minimizing residual oil formation. This study underscores the strong interplay between displacement direction and bedding structure, validating AHM’s advantages in characterizing anisotropic reservoirs. By integrating experimental innovation with advanced computational techniques, this work provides critical theoretical insights and practical guidance for optimizing reservoir development strategies and enhancing the accuracy of numerical simulations in complex sandstone reservoirs. Full article

An IN738 alloy with a high Al and Ti contents induces a significant cracking tendency during laser powder bed fusion (LPBF) processing, leading to a mismatch between printability and mechanical properties. Modification of alloy compositions is an effective strategy to enhance the printability and mechanical properties of nickel-based superalloys via LPBF. In this study, the effects of adding 5 wt.%Co on the printability and mechanical properties of LPBF-fabricated IN738 were investigated by using three-dimensional high-resolution micro-computed tomography (micro-CT), electron backscatter diffraction (EBSD), and quasi-static room-temperature tensile tests. The results show that adding 5 wt.%Co can significantly reduce the defect rate and defect size of the LPBF-fabricated IN738 alloy, remarkably improve alloy densification, and optimize printability. Meanwhile, compared with the LPBF-fabricated IN738 alloy, the 5 wt.%Co-IN738 alloy exhibits an excellent balance of strength and ductility in horizontal and vertical directions, both LPBF-fabricated and heat-treated. These results are anticipated to offer valuable guidance for the development of LPBF-fabricated Ni-based superalloys that achieve a favorable balance between printability and mechanical properties. Full article

Objective: This study aimed to systematically evaluate the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on gait, motor function, and balance in patients with Parkinson’s disease (PD) and identify optimal stimulation parameters for clinical application. Methods: This systematic review and meta-analysis of randomized controlled trials (CTs) was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, EMBASE, Cochrane Central, Scopus, and Ovid-LWW were searched until December 2024 for RCTs evaluating the effects of rTMS on PD-related gait, balance, or motor outcomes. Nineteen studies (n = 547) met the inclusion criteria. Data on study characteristics, rTMS protocols (frequency, target area, pulses, session duration, number of sessions, and treatment duration), and outcome measures (freezing of gait questionnaire [FOG-Q], gait speed, Unified Parkinson’s Disease Rating Scale Part III [UPDRS-III], UPDRS total, and timed up and go [TUG] test) were extracted. Effect sizes (Hedges’ g) were pooled using inverse variance meta-analysis, heterogeneity was assessed using I², and publication bias was assessed using funnel plots and Egger’s regression. Results: rTMS produced significant improvements in gait freezing (FOG-Q: g = −0.74; 95% confidence interval [CI] [−1.05, −0.43]; p < 0.001), gait speed (g = 0.62; 95% CI [0.29, 0.95]; p < 0.001), and motor symptoms (UPDRS-III: g = −0.42; 95% CI [−0.70, −0.15]; p = 0.003). No significant effects were observed for UPDRS total (g = 0.18; p = 0.58) or balance (TUG, g = −0.29; p = 0.06). Egger’s test indicated publication bias for gait speed (p = 0.016); however, trim-and-fill imputed zero studies. Subgroup analyses indicated that high-frequency stimulation of the supplementary motor area (SMA) for ≥20 min over 10 sessions (total duration <2 weeks or ≥2 weeks) optimally improved gait speed, whereas low-frequency stimulation targeting M1 and SMA with >1000 pulses per session for 20 min over 10 sessions within <2 weeks most effectively improved the UPDRS-III scores. Conclusions: rTMS exerts moderate and significant benefits on gait and motor performance in PD, particularly when tailored protocols involving SMA or M1 stimulation are employed. High-frequency SMA protocols improve gait speed, whereas low-frequency M1/SMA protocols optimize motor symptom relief. These findings provide evidence-based guidance for rTMS implementation in PD rehabilitation. Full article

With the growing demand for sustainable and high-performance construction materials, alkali-activated materials (AAM) have attracted significant interest as eco-friendly al-ternatives to cement-based systems. Nevertheless, the tensile ductility and AAM–concrete interfacial bonding of polyethylene fiber-reinforced AAM remain insufficiently understood, and systematic knowledge on how activator modulus governs these multi-scale properties is still limited. This study aims to clarify how activator modulus (Ms = 0, 0.5, 0.8, 1.1, 1.4) influences the mechanical, interfacial, and microstructural behavior of an engineered AAM reinforced with polyethylene fibers. The effects are investigated through uniaxial tensile tests, single-fiber pull-out experiments, bond tests with concrete, and microstructural analyses (SEM, XRD, CT). Results show that an activator modulus of 1.1 yields the best overall performance, achieving a 28-day tensile strength of 3.77 MPa and ultimate tensile strain of 3.68%, representing increases of 231% and 64.6% compared with a modulus of 0. Microstructural observations confirmed that the optimized modulus promotes extensive gel formation, improves fiber–matrix interfacial bonding, and enhances strain-hardening with multiple microcracks. Interfacial tests further demonstrated that Ms strongly affects bond performance between AAM and concrete, with 1.0–1.1 providing balanced adhesion and matrix ductility, while excessive activation (Ms = 1.4) caused interfacial defects and bond deterioration. These findings deepen the understanding of the micromechanical role of activator modulus and provide guidance for the mix design of durable, high-ductility AAM suitable for sustainable infrastructure. Full article

This study investigates the interlayer properties and sustainability of 3D-printed ultra-high-performance concrete (UHPC) modified with antimony tailings (ATs). The different AT ratios considered were 2.7, 5.4, 8.1, 10.8, and 13.5 wt% additions. The mechanical experiments show the optimal concentration resulting in compressive and flexural strength of 11.2% and 17.2% enhancement at 28 days, respectively. SEM analysis revealed that AT enhances the interlayer strength of 3D-printed UHPC and influences the anisotropic behavior of the matrix around steel fibers. X-CT demonstrated that increasing the AT from the compared group to 13.5% reduced the pore volume from 2.02% to 0.30%. Furthermore, an environmental impact assessment of the 10.8 wt% AT exhibited a 32.5% reduction in key indicators including abiotic depletion (ADP), acidification potential (AP), global warming potential (GWP), and ozone depletion potential (ODP). Consequently, UHPC incorporating AT offers superior environmental sustainability in the practical construction of 3D-printed concrete. This research provides practical guidance in optimizing 3D-printed UHPC engineering, further facilitating the integrated design and manufacturing of multi-layer structures. Full article

Background: Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) remains among the most complex procedures in interventional cardiology, with variable technical success and heterogeneous long-term outcomes. Conventional angiographic scores such as J-CTO and PROGRESS-CTO provide only modest predictive accuracy and neglect critical patient and operator-related factors. Artificial intelligence (AI) and machine learning (ML) have emerged as transformative tools, capable of integrating multimodal data and offering enhanced diagnostic, procedural, and prognostic insights. Methods: We performed a structured narrative review of the literature between January 2010 and September 2025 using PubMed, Scopus, and Web of Science. Eligible studies were peer-reviewed original research, reviews, or meta-analyses addressing AI/ML applications in CTO PCI across imaging, procedural planning, and prognostic modeling. A total of 330 records were screened, and 33 studies met the inclusion criteria for qualitative synthesis. Results: AI applications in diagnostic imaging achieved high accuracy, with deep learning on coronary CT angiography yielding AUCs up to 0.87 for CTO detection, and IVUS/OCT segmentation demonstrating reproducibility > 95% compared with expert analysis. In procedural prediction, ML algorithms (XGBoost, LightGBM, CatBoost) outperformed traditional scores, achieving AUCs of 0.73–0.82 versus 0.62–0.70 for J-CTO/PROGRESS-CTO. Prognostic models, particularly CatBoost and neural networks, achieved AUCs of 0.83–0.84 for 5-year mortality in large registries (n ≈ 3200), surpassing regression-based methods. Importantly, comorbidities and functional status emerged as stronger predictors than procedural strategy. Future Directions: AI integration holds promise for real-time guidance in the catheterization laboratory, robotics-assisted PCI, federated learning to overcome data privacy barriers, and multimodality fusion incorporating imaging, clinical, and patient-reported outcomes. However, clinical adoption requires prospective multicenter validation, harmonization of endpoints, bias mitigation, and regulatory oversight. Conclusions: AI represents a paradigm shift in CTO PCI, providing superior accuracy over conventional risk models and enabling patient-centered risk prediction. With continued advances in federated learning, multimodality integration, and explainable AI, translation from research to routine practice appears within reach. Full article

Coronary artery bypass grafting (CABG) remains a cornerstone of treatment for patients with advanced or complex coronary artery disease, yet long-term success is influenced by graft patency, progression of native disease, and ventricular remodeling. Optimizing the follow-up of these patients requires a structured approach in which multimodality cardiovascular imaging plays a central role. Echocardiography remains the first-line modality, providing readily available assessment of ventricular function, valvular competence, and wall motion, while advanced techniques, such as strain imaging and myocardial work, enhance sensitivity for subclinical dysfunction. Coronary computed tomography angiography (CCTA) offers excellent diagnostic accuracy for graft patency and native coronary anatomy, with emerging applications of CT perfusion and fractional flow reserve derived from CT (FFR-CT) expanding its ability to assess lesion-specific ischemia. Cardiovascular magnetic resonance (CMR) provides comprehensive tissue characterization, quantifying scar burden, viability, and inducible ischemia, and stress CMR protocols have demonstrated both safety and independent prognostic value in post-CABG cohorts. Nuclear imaging with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) remains essential for quantifying perfusion, viability, and absolute myocardial blood flow, with hybrid PET/CT approaches offering further refinement in patients with recurrent symptoms. In patients after CABG, multimodality imaging is tailored to the patient’s characteristics, symptoms, and pre-test probability of disease progression. In asymptomatic patients, imaging focuses on surveillance, risk stratification, and the early detection of subclinical abnormalities, whereas in symptomatic individuals, it focuses on establishing the diagnosis, defining prognosis, and guiding therapeutic interventions. Therefore, the aim of our review is to propose updated and comprehensive guidance on the crucial role of multimodality cardiovascular imaging in the evaluation and management of post-CABG patients and to provide a practical, evidence-based framework for optimizing outcomes. Full article

Background/Objectives: This study investigates the effect of mild cyclic loads on the stress state of degenerative knee joint cartilages using a combination of experimental data and numerical modeling. Methods: A three-dimensional finite element model of the knee joint was developed based on CT scans, incorporating key components such as the femur, tibia, cartilage layers, and meniscus. Special attention was given to the mechanical properties of cartilages, which were determined through high-sensitivity dynamometer tests of cartilage samples. The experimentally obtained force–displacement curves for cartilage samples affected by third-degree gonarthrosis were integrated into the numerical model. This allowed for an in-depth investigation of the interactions between neighboring tissues of the knee joint under cyclic loading and unloading conditions. Results: Experimental data revealed nonlinear mechanical behavior of cartilage under loading and unloading conditions, characterized by an elastic hysteresis loop. Experimental results demonstrated that degenerated cartilage, under small stresses (up to 0.13 MPa), retains an elastic hysteresis behavior. The numerical simulation provided insights into the stress distribution within the knee joint components, revealing that even in cases of cartilage degeneration, as long as its structural integrity is maintained, mild loads do not cause sufficient stress concentrators, while the longitudinal tears in the same conditions cause the increment of stress values up to 20%. Conclusions: Findings contribute to a better understanding of the mechanical response of degenerative cartilage and offer valuable guidance for the development of therapeutic and rehabilitation strategies for patients with degenerative tissue diseases. Full article

To improve synthetic CT (sCT) generation from cone-beam CT (CBCT) in radiotherapy, we propose a multiscale segmentation-guided diffusion framework. The proposed model integrates anatomical priors across multiple spatial resolutions through a segmentation mask pyramid and introduces a scale-specific loss function to guide learning at each level. When evaluated on the SynthRAD2023 brain dataset, our model achieves a mean absolute error (MAE) of 61.82 HU, a peak signal-to-noise ratio (PSNR) of 32.05 dB, and a structural similarity index (SSIM) of 0.90, outperforming baseline models. These results suggest that multiscale anatomical guidance can improve the fidelity and anatomical consistency of sCT images, thus facilitating high-quality CBCT-to-CT translation in radiotherapy applications. Full article

Background: While the 2024 ESC Guidelines provide guidance on utilising incidental CAC findings from non-gated CT scans to enhance risk stratification and guide treatment decisions, there remain gaps in detailed protocols for managing such incidental findings, particularly in inpatient settings. An incidental finding of CAC in a patient without known atherosclerosis provides an opportunity to assess cardiac risk, promote risk factor optimisation and evaluate need for further cardiac work up. The aim of this study was to assess the prevalence of incidental coronary artery calcification on non-cardiac dedicated gated CT thorax scans among general medical inpatients and to evaluate the subsequent management of these findings. Methods: This was a single-centre retrospective observational study of consecutive general medical inpatients aged 40–75, who had undergone a non-cardiac gated CT thorax during their admission, between February and March 2025. Data were collected using local electronic health records. Exclusion criteria were patients with known ischaemic heart disease (IHD). Risk factor assessment was noted by documentation of smoking status, hypertension, diabetes and low-density lipoprotein (LDL) values. Results: A total of 186 patients with thoracic CT scans were identified. On review of all CT reports, 53 (28.4%) patients had CAC reported, of whom 17 had known IHD. Therefore 36 (19.4%) patients were identified for further analysis. An exercise stress test was booked in none of the patients. A coronary angiogram was booked in 1 patient. Conclusions: One fifth of medical inpatients in our study had a new finding of CAC on thoracic imaging. Cardiovascular risk factors of LDL and HbA1c were checked in less than half of patients. None of these patients went on to have functional testing. There is a valuable opportunity to optimise cardiac risk factors and evaluate the need for functional testing in a subset of patients with CAC reported on non-cardiac CTs. This can be facilitated by raising awareness and implementing a flowchart tool for hospital physicians to reference. Full article

Background and Objectives: Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL) is a T-cell lymphoma that has shown an interest in the medical community in recent years. Given its emerging clinical relevance, accurate imaging plays a crucial role in diagnosis, staging, and follow-up. This systematic review aims to evaluate the role of Fluorine-18 Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the staging and follow-up of patients with BIA-ALCL, focusing on its diagnostic accuracy and clinical impact. Materials and Methods: A systematic search of PubMed and National Center for Biotechnology Information (NCBI) was conducted to identify studies assessing the use of 18F-FDG PET/CT in BIA-ALCL up to and including 15 April 2024, using the following keywords “breast implant-associated anaplastic large cell lymphoma” AND “PET/CT” AND “BIA-ALCL”. Data regarding the role of PET/CT in disease detection, staging, therapeutic guidance, and post-treatment surveillance was analyzed and synthesized in a tabulated format for comparative analysis. Given study heterogeneity, findings were synthesized narratively and diagnostic performance metrics were summarized descriptively, and no formal risk-of-bias assessment was performed due to the descriptive, case-based nature of evidence. Results: A total of 28 studies met the inclusion criteria, comprising 27 individual case reports and one case series that included seven patients. Across these studies, 18F-FDG PET/CT demonstrated diagnostic utility in the evaluation of BIA-ALCL, serving primarily for initial disease staging in 27 cases and for monitoring treatment response in 16 cases. Discussion: The review’s limitations include potential search bias due to variable radiotracer terminology and the restriction to English-language studies, which may limit literature retrieval and generalizability. Conclusions: Thus, 18F-FDG PET/CT demonstrated significant value in early lesion detection, accurate staging, assisting in monitoring treatment response and detecting recurrence. Full article

Parathyroid carcinoma (PC) is an exceedingly rare endocrine malignancy, accounting for less than 1% of all primary hyperparathyroidism (pHPT) cases. It typically presents with pronounced hypercalcemia and markedly elevated parathyroid hormone (PTH) levels. Accurate imaging plays a pivotal role in diagnosis, staging, surgical planning, and long-term surveillance, although differentiating PC from benign disease on imaging remains a significant challenge. A multimodal imaging strategy combining cervical ultrasonography (US) and nuclear medicine techniques provides high sensitivity for lesion detection. Ultrasonography with advanced detective flow imaging allows detailed anatomical assessment and evaluation of vascular patterns of the primary tumor. [^99mTc]Tc-methoxyisobutylisonitrile ([^99mTc]Tc-MIBI) scintigraphy frequently demonstrates prolonged tracer retention in PC, while [¹⁸F]fluorocholine positron emission tomography/computed tomography (PET/CT) and positron emission tomography/magnetic resonance (PET/MR) imaging have shown superior performance for detecting both primary tumors and metastatic disease due to its higher spatial resolution and higher molecular sensitivity. [¹⁸F]FDG PET serves as an adjunct modality for identifying aggressive, metabolically active lesions. Emerging radiotracers such as [¹⁸F]-fibroblast activation protein inhibitor ([¹⁸F]FAPI) and [⁶⁸Ga]Ga-trivehexin have shown potential in cases where initial imaging is inconclusive. Theranostic strategies that integrate molecular imaging with targeted radioligand therapy may transform PC management by enabling personalized treatment approaches tailored to each tumor’s biological and imaging characteristics. This review aims to evaluate available imaging modalities for PC diagnosis and provide guidance for their clinical application. Full article

Background: Pulmonary arteriovenous malformations (PAVMs) are abnormal vascular connections between the pulmonary arteries and veins, often leading to significant clinical complications. Embolisation has become the primary therapeutic modality for managing symptomatic PAVMs, with advancements in both technique and technology improving patient outcomes. Recent progress includes the introduction of precisely targeted embolisation techniques, such as cone-beam computed tomography (CBCT) guidance and three-dimensional imaging, enabling more accurate identification and treatment of complex, multiple, or peripheral lesions. Additionally, vascular plugs and microcoils have demonstrated superior performance in terms of lower recurrence rates and more complete occlusion of feeding vessels compared to traditional devices. The use of endovascular navigation systems has further enhanced procedural success. Aim: The objective of this review is to explore the latest innovations in embolisation therapies for PAVMs, emphasising emerging techniques, devices, and strategies that have refined treatment efficacy and safety. Methods: We performed a focused literature search to identify key publications relevant to current approaches in thoracic vascular imaging. Searches were conducted in PubMed and Embase using combinations of terms related to ‘thoracic imaging,’ ‘vascular,’ ‘Computed Tomography (CT) angiography,’ and ‘MRI.’ Additional articles were identified from reference lists of major reviews and landmark studies. Priority was given to publications from the past 10 years, with older key papers included when historically relevant. Selection was based on thematic relevance rather than formal criteria. Conclusions: Advancements in patient selection and pre-procedural planning, driven by enhanced imaging modalities such as CT pulmonary angiography (CTPA) and contrast-enhanced ultrasound, have led to improved outcomes and reduced complications. While the benefits of embolisation are well-documented, ongoing research continues to explore the long-term outcomes, including post-embolisation pulmonary function, recurrence rates, and quality of life improvements. Full article

Background/Objectives: Screw placement accuracy with robotic guidance shows better results than freehand techniques, yet there is scant data for region-specific outcomes, fusion rates, and complication profiles in different populations. The purpose of this study is to assess and describe screw-rod accuracy, fusion rates, and complications of robot-assisted pedicle screw placement in a Spanish cohort. Methods: Robotic-guided technique for thoracolumbar fusion in 115 patients (July 2020–January 2025) using ExcelsiusGPS^® platform (Globus Medical Inc., Audubon, PA, USA). Inclusion criteria: adults (≥18 years) with postoperative CT to assess accuracy. Primary outcomes were screw accuracy (assessed on the Gertzbein–Robbins scale), fusion rates, and complications (infection, osteolysis, and subsidence). Jamovi 2.6 was employed for statistical analysis. Results: Of a total of 726 screws implanted, 590 screws (95 patients) were studied: 584 (99%) Grade A, 5 (0.8%) Grade B, and 1 (0.2%) Grade C. Fusion was achieved in 85 out of 95 patients (89.5%). Complications included superficial infections (3/115 patients, 2.6%) and asymptomatic osteolysis (8/95 patients, 8.4%, mostly at S1). There was no screw subsidence or removal. Conclusions: Robotic-guided pedicle screw placement demonstrated exceptional accuracy (99% Grade A), high fusion success (89.5%), and minimal complications in this Spanish cohort, supporting its clinical utility for spinal instrumentation. Full article

Background and Objectives: Postoperative enterocutaneous fistulas, defined as abnormal communications between the intestinal lumen and the skin, represent one of the most challenging complications following abdominal surgery. Regenerative medicine, particularly through the use of adipose-derived mesenchymal stem cells (ADSCs), has recently emerged as a promising therapeutic option for chronic inflammatory and non-healing conditions. However, most studies have focused on complex perianal fistulas in Crohn’s disease. This prospective, single-center observational study aimed to evaluate the feasibility, safety, and preliminary efficacy of autologous ADSC injection in patients with complex postoperative enterocutaneous fistulas. Materials and Methods: Six patients (four males and two females) with persistent postoperative enterocutaneous fistulas were enrolled. Autologous adipose tissue was harvested via lipoaspiration from the abdominal wall or flank and processed in a GMP-certified laboratory to obtain a suspension containing 5–10 million viable ADSCs in 3–5 mL of isotonic solution. ADSCs were injected directly into the fistulous tract under ultrasound guidance, following CT image review. Clinical and radiologic follow-up was performed to assess closure and output reduction. Results: Four of the six patients (66.7%) achieved complete fistula closure, with no residual output and radiologic confirmation of healing within 4–12 weeks. One patient (16.7%) demonstrated a significant reduction in fistula output (>80%), while another (16.7%) showed minimal improvement and subsequently required surgical repair at 6 weeks. No complications related to ADSC administration were observed. Conclusions: Autologous ADSC therapy appears to be a feasible, safe, and minimally invasive option for managing complex postoperative enterocutaneous fistulas. These encouraging preliminary results—showing complete closure in two-thirds of treated patients—support further investigation through larger, controlled trials to validate these findings and optimize treatment protocols. Full article