Search Results (1,276)

Background: COVID-19 is primarily a respiratory disease, but increasing evidence suggests possible oral and maxillofacial complications. This study presents a case series of post-COVID maxillary osteonecrosis (PC-RONJ) cases from western Romania and explores the possible association between SARS-CoV-2 infection, its treatment, and this complication. Methods: We conducted a multicenter retrospective case series of two patients with recent PCR-confirmed SARS-CoV-2 infection who subsequently developed maxillary osteonecrosis (ONC) between 2021 and 2023. Clinical examination, CT imaging (including 3D reconstructions), and ENT assessment were used to assess the severity of the disease. All medical records were reviewed to identify comorbidities, details of COVID-19 treatment, and the appearance of maxillofacial symptoms. Results: Both patients had been hospitalized for severe COVID-19 and treated according to the national protocol with systemic corticosteroids, oxygen therapy, anticoagulation, and antivirals. CT scans revealed marked osteolytic destruction of the maxilla and maxillary sinus walls, with extension toward adjacent facial bones. Microbiological analysis revealed a complex polymicrobial profile, including Gram-positive and Gram-negative bacteria as well as opportunistic fungal species, consistent with a chronic biofilm-associated infectious process. Patients received surgical treatment, followed by local care and, in both cases, prosthetic rehabilitation with maxillary obturators, which improved speech, chewing, and oral function. Conclusions: This case series suggests a possible association between severe COVID-19, its treatment, and subsequent maxillary osteonecrosis in susceptible patients; however, the small number of cases precludes causal inference. To our knowledge, this is the first Romanian report describing such cases in patients without prior antiresorptive therapy. These findings highlight the need for careful use of systemic corticosteroids and vigilant post-recovery monitoring of maxillofacial complications. Further studies are required to clarify the underlying mechanisms and risk factors. Full article

Cement stabilized macadam (CSM) bases are prone to cracking and void damage under long-term traffic loading and environmental actions, which accelerates structural deterioration. Although grouting is an effective method for treating such concealed defects, laboratory-based evaluation of repair effectiveness remains limited. In this study, field-cored CSM specimens were recombined in a cylindrical mold to simulate four void conditions (1/4, 2/4, 3/4, and 4/4), and repaired using an inorganic cementitious composite grouting material based on ultra-fine cement and high-belite sulphoaluminate cement (HBSAC), and modified with ethylene-vinyl acetate (EVA) latex, wollastonite (WO) whiskers, and polyvinyl alcohol (PVA) fibers. The repair effectiveness was evaluated through ultrasonic testing, capacitance measurement, uniaxial compression with acoustic emission (AE) monitoring, and computed tomography (CT). The results show that the longitudinal wave velocity of all repaired groups increases continuously with curing time, with a maximum increase of 21.98% at 28 days. The normalized capacitance response exhibits clear time- and layer-dependent variation, with the 4/4 group showing the most pronounced spatial heterogeneity. In the uniaxial compression tests, the peak load increases from 181 kN in the control group to 201–286 kN in the repaired groups, while the tensile-related AE event proportion increases from 77.35% in the 1/4 group to 89.38% in the 4/4 group. CT analysis shows that the proportion of micropores smaller than 1 mm³ increases from 66.3% to 82.7%, whereas the proportion of pores larger than 100 mm³ decreases from 46.5% to 21.6% after repair. These results demonstrate that the composite grouting material provides effective filling, structural reconstruction, and mechanical enhancement for void-damaged CSM, and that the proposed multi-source characterization framework is suitable for evaluating grouting repair performance. Full article

The manuscript details the influence of high-temperature and high-shear processing, as well as radiation sterilization, on properties of bioresorbable and osteoconductive, patient-tailored alloplastic scaffolds for guided bone regeneration. Functionalized poly(l-lactide-co-d,l-lactide) copolymer filled with hydroxyapatite was used to produce two personalized implants for upper and lower jaw reconstruction via 3D printing. Morphology analysis (SEM, µCT), gel permeation chromatography, and thermal analysis quantified the effects of melt processing and sterilization on chain structure. Physical properties of sterilized parts, such as hardness and density, proved suitable for bone implants. Removal of the upper jaw implant after 4 months and of the lower jaw substitute after 18 months enabled monitoring of bioresorption and tissue regrowth over time. Gradual overgrowth of the implants with human tissue, initiated by the osteoconductive filler, was observed, along with time-dependent polylactide degradation, showing up to 92% molar mass reduction. The medical procedures confirmed safety, nontoxicity, non-allergenicity, and, most importantly, the tissue-forming properties of the polylactide-based formulation. Full article

There are numerous benefits associated with creating digital copies of anatomical structures, which can be used during patient diagnosis. Such models can be used not only for visualization, but also in order to assess the condition of the patient. As advances in both medical imaging and 3D graphics are made, it is necessary to determine areas of application of the known reconstruction algorithms. Specifically, it is crucial to find advantages and disadvantages of known approaches to mesh generation, depending on the properties of the object and compare the quality of their results. In order to provide reliable ground-truth data, three 3D models with features resembling those identified in anatomical structures have been created. Based on these meshes, sets of CT-like DICOM images have been generated. Five different reconstruction approaches were proposed: using 3D occupancy information directly, two ways of obtaining point clouds and two methods that utilize Signed Distance Field. A neural network architecture for the SDF upsampling has also been presented. The obtained results justify the popularity of the Marching Cubes algorithm, as it produced accurate reconstructions most reliably. However, for certain scenarios, promising alternatives have been found. The presented outcomes make it clear that the approach to reconstruction must be tailored to the specific problem. Full article

Background/Objectives: Lisfranc joint injuries are complex midfoot pathologies frequently associated with subtle radiologic findings and delayed diagnosis. Although ligamentous disruption is considered the primary mechanism, the contribution of intrinsic osseous morphology remains insufficiently investigated. Previous studies have primarily relied on two-dimensional measurements and limited morphometric parameters. Therefore, this study aimed to provide a comprehensive three-dimensional (3D) computed tomography (CT) based morphometric evaluation of the medial and central columns of the Lisfranc joint and to determine whether specific bony parameters are associated with injury predisposition. Methods: A total of 48 CT scans, including 23 from patients with Lisfranc joint injuries and 25 from healthy controls without midfoot trauma, were retrospectively analyzed. For both groups, 3D models of the first three metatarsals (M1–M3) and cuneiforms (C1–C3) were reconstructed to measure bone length, articular surface areas, volumes, M1–M2/M2–M3 depth differences, and dorsal step-off (dorsal subluxation of M2 relative to C2). Correlations of these measurements with M2 length were additionally assessed in each group. Results: Comparisons between injury and healthy control groups revealed no significant differences in bony morphometrics (p > 0.05). Correlation analysis showed that a longer M2 were associated with greater cuneiform volumes and larger metatarsal articular surface areas (p < 0.05). Conclusions: This comprehensive 3D morphometric assessment of the Lisfranc joint indicates that intrinsic bony anatomy alone is unlikely to represent a primary predisposing factor for Lisfranc injuries. The observed positive relationship between M2 length and cuneiform articular surface areas and volumes demonstrates structural interdependence within the medial and central columns. Overall, injury susceptibility does not appear to be explained by variations in osseous morphology alone. Full article

Background/Objectives: To determine the optimal reconstruction parameters for accurate visualization of peripheral in-stent restenosis using photon-counting detector CT (PCD-CT), and to evaluate its potential advantages over energy-integrated detector CT (EID-CT). Methods: Endovascular peripheral stents with varying degrees of in-stent restenosis were scanned in a custom-made phantom using EID-CT (Somatom Force) and PCD-CT (Naeotom Alpha) under clinical acquisition protocols. EID-CT images were reconstructed with Bv40 and Bv59 kernels at 512 matrices. PCD-CT data were acquired in standard-resolution (SR) and ultra-high-resolution (UHR) modes. In both modes, images were reconstructed with multiple kernels (Bv40, Bv56 and Bv72) and matrix sizes (512 and 1024 matrix). In SR mode, additional virtual monoenergetic images (40–100 keV) were generated, while UHR mode included only polychromatic reconstructions. Quantitative image quality (noise, contrast, contrast-to-noise ratio [CNR]) was measured, and two blinded readers performed qualitative assessments of restenosis visualization. Results: PCD-CT with SR mode at VMI 40 keV achieved the highest image contrast and CNR, significantly outperforming EID-CT and PCD-CT_UHR under matched conditions (all p < 0.05). The sharper reconstruction kernel further enhanced the image contrast and improved subjective visualization despite increased image noise. Both readers ranked PCD-CT_{SR-Bv72-40keV} at 1024 matrix highest for detecting all degrees of restenosis, with excellent inter-reader agreement (ρ > 0.80). Conclusions: PCD-CT in SR mode at VMI 40 keV, specifically using the Bv72 kernel with a 1024 matrix, optimizes the visualization of peripheral in-stent restenosis. Compared to EID-CT, PCD-CT provides superior image quality and detectability of restenosis. Full article

Accurate delineation of tumor margins is critical for complete resection and minimizing recurrence, yet existing imaging modalities such as MRI, CT, and fluorescence imaging suffer from limitations including high cost, limited accessibility, and intraoperative constraints. In this study, we propose a low-cost, non-invasive approach for subsurface imaging based on near-infrared (NIR) illumination combined with deep learning. A controlled experimental setup was developed in which structured patterns displayed on an electronic paper screen were concealed beneath a tissue-mimicking chicken phantom and imaged using a NIR-sensitive camera under halogen illumination. A convolutional autoencoder based on a U-Net architecture was trained on approximately 10,000 paired samples to reconstruct hidden structures from highly scattered surface images. The proposed method achieved strong reconstruction performance, with the best model reaching a peak signal-to-noise ratio (PSNR) of 20.14 dB, structural similarity index (SSIM) of 0.92, and feature similarity index (FSIM) of 0.94, significantly outperforming conventional Wiener filtering. Qualitative results demonstrated accurate recovery of subsurface shapes with minor smoothing artifacts. While generalization to out-of-distribution samples remains limited, the findings highlight the potential of combining NIR imaging and deep learning for safe, rapid, and cost-effective subsurface visualization. This work establishes a foundation for future development toward clinically relevant tumor margin detection. Full article

Background/Objectives: Temporal bone surgery in children is technically challenging due to their smaller anatomical structures, developmental differences, and the closer proximity of critical neurovascular structures. The limited availability of conventional training materials and pediatric cadaveric specimens has led to greater enthusiasm for simulation-based methods. The aim of this systematic review was to identify existing otologic simulation models and evaluate their anatomical accuracy, teaching effectiveness, and supporting evidence. Methods: In accordance with PRISMA guidelines, the PubMed, Embase, Scopus, and Cochrane Library databases were searched for studies reporting simulation tools for pediatric otologic surgery. Articles describing three-dimensional printed (3DP) models, virtual reality (VR) platforms, cadaver specimens, and animal models were included. Studies focusing on children and providing educational outcomes were selected. The extracted data were synthetized and analytically discussed. Results: Thirteen studies met the inclusion criteria: nine on 3DP models and four on VR environments. No research involving cadavers or animals was identified. 3DP models exhibited consistent anatomical accuracy and notable educational advantages. Five studies used surveys for their evaluations, and three relied on expert observer assessments. The studies including validation analyses showed a high correlation between printed models and computed tomography (CT) images. VR systems supported anatomical reconstruction and segmentation tasks, as well as guided simulation exercises. However, most of the research consisted of feasibility studies with limited participant groups. Conclusions: Simulation-based training with 3DP and VR models could be ethical and accurate methods for obtaining relevant skills in pediatric otologic surgery. The reviewed data suggest that these tools may be suitable as a first-line step within an integrated, multimodal training pathway prior to direct patient contact. Full article

The reconstruction of complex orbitomaxillary defects requires biomaterials that can simultaneously provide structural stability, biocompatibility, and accurate restoration of facial volume and contour. While rigid polymers such as polyetheretherketone (PEEK) offer reliable mechanical support, they do not adequately replicate the viscoelastic behavior of soft tissues. This report presents a translational revision case employing a personalized hybrid biomaterial approach that combines a 3D-printed PEEK implant for structural orbital floor support with a patient-specific polydimethylsiloxane (PDMS) implant for malar volumetric augmentation. Reconstruction was planned using CT segmentation and contralateral mirroring. Patient-specific implants were subsequently designed using CAD/CAM techniques, combining a rigid PEEK implant for structural orbital support with a flexible PDMS implant for malar volumetric augmentation with complementary mechanical properties. Revision surgery included the removal of inadequately positioned titanium hardware, the release of incarcerated extraocular muscles, and the restoration of orbital anatomy and facial symmetry. Postoperative imaging demonstrated stable implant positioning and sustained orbitomaxillary stability. Despite successful anatomical reconstruction, residual functional sequelae, including strabismus related to the severity of the initial orbital trauma, persisted and were addressed separately in a staged manner, resulting in satisfactory ocular alignment and resolution of diplopia in primary gaze. This case underscores the complementary functional roles of rigid and elastic polymers and highlights the translational potential of PDMS as a permanent, patient-specific implant material for volumetric and contour restoration in craniofacial reconstruction. Full article

Background: Autologous fat grafts are widely used for skull base reconstruction following endoscopic endonasal surgery. However, uncertainty regarding their postoperative volumetric evolution may complicate the distinction between expected postoperative changes and residual or recurrent disease on imaging. Methods: We performed a retrospective volumetric imaging analysis of patients undergoing endoscopic endonasal skull base surgery with reconstruction using autologous fat and the 3F technique between 2013 and 2023. Fat graft volumes were measured on postoperative day 1 CT scans and on 3-, 9-, and 15-month postoperative MRI using standardized volumetric segmentation analysis (method described in detail in the main text). It should be noted that baseline measurements were derived from CT, whereas follow-up assessments were performed using MRI. Resorption rates were correlated with demographic, pathological, surgical, and postoperative variables. Results: Thirty-four patients met inclusion criteria. Mean initial fat graft volume was 3.01 ± 2.65 cm³. Overall, fat graft volume demonstrated a consistent temporal decline, with mean reductions of 56.8% at 3 months, 75.3% at 9 months, and 81.8% at 15 months. In subgroup analysis, differences in resorption were observed according to surgical approach, with higher resorption following transsellar compared with transtuberculum approaches (87.4% vs. 74.8% at 15 months, p = 0.042). These findings were closely related to graft compartment, although compartment and surgical approach showed substantial overlap in this cohort. No significant associations were detected between resorption rate and age, sex, comorbidities, postoperative CSF leak, extent of resection, or adjuvant radiotherapy. Conclusions: Autologous fat grafts used for skull base reconstruction demonstrate substantial early postoperative resorption followed by slower progressive volume loss. Recipient anatomical compartment was associated with differences in observed resorption patterns, although this relationship should be interpreted in the context of overlap with surgical approach and limited sample size. These findings may assist in improving interpretation of postoperative imaging by clarifying the expected temporal pattern of fat graft evolution after endoscopic skull base reconstruction. Full article

Purpose: To critically evaluate the role or effect of platelet-rich plasma (PRP) in anterior cruciate ligament (ACL) reconstruction in terms of clinical and radiological outcomes. Method: We conducted a systematic search of PubMed, Embase, the Cochrane Library, and Web of Science to identify relevant studies. Clinical outcomes included the Visual Analogue Scale (VAS), International Knee Documentation Committee (IKDC) subjective and objective evaluations, Lysholm score, Tegner score, anterior knee laxity, Knee Injury and Osteoarthritis Outcome Score (KOOS), Kujala score, Victorian Institute of Sport Assessment (VISA) scale, proprioception, isokinetic strength, and physical examination tests (anterior drawer, Lachman, and pivot-shift tests). Radiological outcomes encompassed measures obtained via magnetic resonance imaging (MRI), computed tomography (CT), X-ray, and ultrasound. Statistical significance was defined as a p value < 0.05, and all analyses were performed using R software (version 4.1.3). Results: A total of 23 studies, including 19 randomized controlled trials, met the inclusion criteria, encompassing 1072 patients overall. The meta-analysis showed significant differences between PRP group and non-PRP group with regard to VAS score at 6- and 12-month follow-up, Lysholm score at 6-month follow-up, and Tegner score at 6-month follow-up. Meta-regression showed that the two group differences in VAS score changed significantly with follow-up time (p < 0.01). In terms of radiological findings, about half of the assessments favored PRP to facilitate the graft maturation and integration at 6-month follow-up. Conclusions: PRP application in ACL reconstruction compared with non-PRP, may produce short-term but not long-term clinical outcomes such as VAS score, Lysholm score and Tegner score. While some short-term statistical differences exist, their magnitude and durability do not yet justify routine clinical adoption of PRP in ACL reconstruction. Larger samples and higher-quality studies are needed to support our results and further explore the advantages of PRP in other aspects. Level of evidence: Level II. Full article

Acute traumatic aortic injury (ATAI) is a rare but life-threatening consequence of blunt trauma that requires prompt diagnosis and accurate imaging assessment. This review presents an imaging-based approach to ATAI, with emphasis on computed tomography angiography (CTA) as the first-line modality for diagnosis, grading, treatment planning, and follow-up. CTA enables the detection of both direct and indirect signs while also allowing for the assessment of lesion severity, extent, and associated findings that may influence management. Familiarity with common mimics and anatomic variants improves diagnostic confidence and helps avoid false positive interpretations. Careful protocol optimization, including multiphasic acquisition, bolus timing, and postprocessing reconstructions, can further enhance image quality and diagnostic performance. Recognition of patient-related and technical CTA artifacts, along with strategies to reduce them, including the selective use of ECG-gated CTA, may further decrease diagnostic uncertainty. We also discuss the complementary roles of emerging CT technologies and magnetic resonance angiography in selected patients. Finally, we review current classification systems, imaging-guided management, post-treatment surveillance, and potential complications. Awareness of ATAI imaging findings, protocol optimization, and diagnostic pitfalls is essential for accurate interpretation and effective multidisciplinary care. Full article

Background/Objectives: We aim to evaluate whether digital imaging and communications in medicine (DICOM)-level deep learning-based iodine-boosting applied to dual-source dual-energy computed tomography (DECT) source DICOM improves image quality in low-iodine-dose abdominal DECT in adults undergoing post-procedure follow-up computed tomography (CT). Methods: This retrospective study included 43 adults (April–September 2025) who underwent dynamic dual-source DECT using a low-iodine protocol. Three CT reconstructions were compared: mixed images, conventional 50-keV virtual monoenergetic images (VMIs), and 50-keV VMIs generated after applying DICOM-based deep learning iodine-boosting/denoising to the tube-specific dual-energy source DICOM series prior to VMI/iodine-map reconstruction (deep learning-based reconstruction [DLR]-VMI). Iodine material density (IMD) images were compared between the conventional and DLR-processed datasets. Quantitative attenuation and signal-to-noise ratio (SNR) were assessed using paired and repeated-measures tests. Image quality was scored by two readers using a five-point Likert scale. Results: Attenuation varied across CT reconstructions for all regions of interest in both phases (all overall p < 0.001). Liver attenuation increased from 94.9 ± 22.0 Hounsfield units (HU) (VMI) to 114.5 ± 34.6 HU (DLR-VMI) during the arterial phase and from 127.6 ± 25.6 HU to 166.6 ± 39.9 HU during the portal venous phase (both p < 0.001). Liver SNR improved with DLR-VMI compared to VMI (arterial: 9.11 ± 3.62 vs. 6.06 ± 1.90; portal: 12.74 ± 3.56 vs. 7.90 ± 1.82; both p < 0.001). On IMD images, DLR increased HU-equivalent values and liver SNR (arterial: 5.20 ± 2.89 vs. 2.61 ± 1.39; portal: 9.22 ± 2.81 vs. 4.48 ± 1.28; both p < 0.001). Qualitatively, DLR-VMI yielded the highest overall image-quality scores for both reviewers in both phases (Reviewer 1, arterial/portal: 4 (4–5)/5 (4–5); Reviewer 2, arterial/portal: 4 (3–4)/4 (4–4)). DLR also improved the overall image quality of IMD images for both reviewers (all p < 0.001). Conclusions: Raw DICOM-level iodine-boosting DLR applied to dual-source DECT-source DICOM enabled enhanced image quality and improved quantitative and qualitative metrics in low-iodine-dose abdominal DECT. Full article

Purpose: Thymic involution, a hallmark of immune ageing, is associated with chronic low-grade inflammation (“inflammaging”) and has been implicated in age-associated inflammatory diseases, including atherosclerosis. This study aimed to evaluate the association between persistent thymus and coronary artery calcification based on the Agatston score. Materials and Methods: In an exploratory effort, we retrospectively analyzed 206 patients aged 40–64 years who underwent ECG-triggered thoracic CT between 2019 and 2024. Coronary artery calcifications were quantified on virtual non-contrast reconstructions using the Agatston score. Thymic tissue was graded on a five-point scale based on the extent of fatty replacement, with higher grades indicating greater thymic preservation. Results: The cohort included 126 men and 80 women. Complete fatty replacement of the thymus (Grade 0) was seen more often in men compared to women (51/126 vs. 18/80; p = 0.011). Linear regression analysis revealed a significant inverse association between thymus grade and coronary Agatston score (Beta (B) = −28.8 (95% CI −45.3 to −12.3); p = 0.001). After adjusting for age and sex, higher thymic grades remained significantly associated with lower coronary Agatston scores (B = −22.2 (95% CI: −41.7 to −2.6); p = 0.03). Further analysis with adjustments for cardiovascular risk factors was not performed. Conclusions: Residual thymic tissue was significantly inversely associated with coronary artery calcification, and this association persisted after adjustment for age and sex. These findings support the hypothetical concept that morphologically detectable thymic remnants may reflect interindividual differences in immune ageing and inflammaging that are associated with age-related inflammatory disease phenotypes. The results of this hypothesis-generating study give incentive to further investigate the nature and strength of these associations in prospective studies. Full article

Volumetric modulated arc therapy-computed tomography (VMAT-CT), which is the CT reconstructed using the portal images collected during VMAT, can potentially be an effective onsite imaging tool. The goal of this study was to propose an iterative reconstruction algorithm that can further improve the image quality of VMAT-CT and reduce the number of failed reconstructions. An iterative algorithm combining total variation (TV) with block-matching and 3D filtering (BM3D) was proposed, addressing the L1-L2 regularization problem using the split Bregman method. We collected portal images from 67 VMAT cases including 50 phantom and 17 real-patient cases. Both Feldkamp–Davis–Kress (FDK) and TV-BM3D iterative algorithms were used to reconstruct VMAT-CT using the collected images. The preprocessing methods developed by our group previously were also used in this study. A total of 48 out of 50 phantom cases and 15 out of 17 real-patient cases were successfully reconstructed using the iterative algorithm together with image preprocessing. In contrast, 39 phantom cases and 8 patient cases could be reconstructed using the original FDK algorithm, and 44 phantom cases and 11 patient cases could be reconstructed using the FDK algorithm together with preprocessing. Compared with the FDK algorithm, the TV-BM3D iterative algorithm significantly improved the image quality of VMAT-CT at all treatment sites. To the best of our knowledge, this study is the first to develop an iterative VMAT-CT reconstruction algorithm. It can be used to reconstruct CT images locally, and is superior to FDK-based algorithms in terms of the success rate and reconstructed image quality. This strongly supports the use of VMAT-CT as a promising imaging tool for treatment monitoring and adaptive radiotherapy. Full article