Search Results (258)

Background/Objectives: Accurate diagnosis of brain tumors is one of the most important challenges in neuro-oncology since tumor classification and volumetric segmentation inform treatment planning. Two-dimensional classification and three-dimensional segmentation deep learning models can augment radiological workflows, particularly if paired with explainable AI techniques to improve model interpretability. The objective of this research was to develop a web-based brain tumor segmentation and classification diagnosis platform. Methods: A diagnosis system was developed combining 2D tumor classification and 3D volumetric segmentation. Classification employed a fine-tuned MobileNetV2 model trained on a glioma, meningioma, pituitary tumor, and normal control dataset. Segmentation employed a SegResNet model trained on BraTS multi-channel MRI with synthetic no-tumor data. A meta-classifier MLP was used for binary tumor detection from volumetric features. Explainability was offered using XRAI maps for 2D predictions and Gaussian overlays for 3D visualizations. The platform was incorporated into a web interface for clinical use. Results: MobileNetV2 2D model recorded 98.09% classification accuracy for tumor classification. 3D SegResNet obtained Dice coefficients around 68–70% for tumor segmentations. The MLP-based tumor detection module recorded 100% detection accuracy. Explainability modules could identify the area of the tumor, and saliency and overlay maps were consistent with real pathological features in both 2D and 3D. Conclusions: Deep learning diagnosis system possesses improved brain tumor classification and segmentation with interpretable outcomes by utilizing XAI techniques. Deployment as a web tool and a user-friendly interface made it suitable for clinical usage in radiology workflows. Full article

Objectives: Nasal reconstructive surgery following skin cancer resection is challenging, with esthetic concerns impacting patients’ quality of life. Non-surgical rhinoplasty may be an alternative to repeated surgeries. This study aimed to evaluate non-surgical rhinoplasty esthetic benefits and subjective patient outcomes after skin cancer resection. Methods: We conducted a retrospective study on patients with post-operative esthetic dissatisfaction after nasal skin cancer surgery, who underwent non-surgical rhinoplasty with hyaluronic acid. Subjective benefits were evaluated with the FACE-Q Rhinoplasty self-questionnaire at three consultations: before injection (baseline), and at one and two months after. Two-dimensional and three-dimensional Vectra H2 photographs were used to assess subjective esthetic concerns and objective volumetric changes. Results: The study included six female patients with an average age of 58.3 years. They had undergone, on average, five nasal surgeries for cancer. The mean FACE-Q scores were 53.3 (±10.31), 77.5 (±4.18), and 79.7 (±6.76), respectively, at baseline, one month, and two months. Significant differences were observed between baseline and one month (p < 0.001) and between baseline and two months (p < 0.001), but not between one and two months. The was a mean volumetric gain of 1.13 mL at one month and 1.19 mL at two months. Conclusions: This preliminary study suggested that hyaluronic acid-based non-surgical rhinoplasty could improve esthetic outcomes and quality of life in patients who had undergone nasal skin cancer surgery. These findings highlight a potential role for this minimally invasive technique in selected post-reconstructive cases, although the small sample size limited the generalizability of the results and underlined the need for further prospective evaluation. Full article

Everolimus (EVE), an mTOR inhibitor, is widely used in solid organ transplantation (SOT) because of its immunosuppressive properties. Due to its narrow therapeutic window and significant pharmacokinetic variability, therapeutic drug monitoring (TDM) is essential for achieving optimal outcomes. We developed and thoroughly validated a robust LC-MS/MS method to measure EVE levels in venous whole blood (WB) and capillary blood collected using two microsampling devices: Mitra™ (volumetric absorptive microsampling, VAMS) and Capitainer^® (quantitative dried blood spot, qDBS). The validation followed EMA and IATDMCT guidelines, assessing linearity (1.27–64.80 ng/mL for WB and 0.50–60 ng/mL for VAMS/qDBS), as well as selectivity, accuracy, precision, matrix effects, recovery, stability, and incurred sample reanalysis. Clinical validation involved 66 matched samples from 33 adult SOT recipients. The method demonstrated high accuracy and precision across all matrices, with no significant carryover or matrix interference. Statistical analysis using Passing–Bablok regression and Bland–Altman plots showed excellent agreement between the microsampling methods and the venous reference. Hematocrit effects were tested both in laboratory conditions and on clinical samples and were found to be negligible. This study provides the first comprehensive analytical and clinical validation of the Mitra and Capitainer devices for EVE monitoring. The validated LC-MS/MS microsampling method supports decentralized, patient-centred TDM, offering a reliable alternative to conventional blood sampling in transplant care. Full article

Peak detection is a fundamental task in spectral and time-series data analysis across diverse scientific and engineering disciplines, yet traditional approaches are highly sensitive to the choice of algorithm parameters, complicating reliable and consistent interpretation. Triggered by the requirement for the energy calibration for the 128 detectors of the PI3SO gamma ray scanner, we introduce a versatile methodology inspired by concepts from persistent homology, extending the traditional notion of persistence to a multi-parameter setting. Our approach systematically explores the space defined by multiple detection parameters and quantifies peak robustness through the hyper-volume in the parameter space where each peak is consistently identified. This volumetric multi-parameter persistence (VM-PP) measure enables robust peak ranking and significantly reduces the sensitivity of detection outcomes to individual parameter selection, demonstrating utility across simulated and experimental spectral datasets. Extensive validation reveals that this method reliably differentiates genuine peaks from noise-induced fluctuations under diverse noise conditions, proving effective in practical spectroscopic calibration scenarios. This framework, general by design, can be readily adapted to diverse signal-processing applications, enhancing interpretability and reliability in complex feature-detection tasks. Full article

Material wear significantly impacts the clinical success and longevity of dental ceramic restorations. This in vivo study aimed to assess the wear behavior of IPS Empress^® glass-ceramic inlays and onlays over 14 years, considering the influence of different antagonist materials. Fifty-four indirect restorations of 21 patients were available for comprehensive wear analysis, with complete follow-up data for up to 14 years. Three-dimensional measurements relied on digitized epoxy resin models produced immediately post-insertion (baseline) and subsequently at 2, 4, and 14 years. The occlusal region on the baseline model was delineated for comparative analysis. Three-dimensional superimpositions with models from subsequent time points were executed to assess wear in terms of average linear wear and volumetric loss. Statistical analyses were conducted in R (version 4.4.1), employing Mann–Whitney U tests (material comparisons) and Wilcoxon signed rank tests (time point comparisons), with a significance threshold of p ≤ 0.05. During the entire study period, an increase in wear was observed at each assessment interval, gradually stabilizing over time. Significant differences in substance loss were found between the follow-up time points, both for mean (−0.536 ± 0.249 mm after 14a) and integrated distance (−18,935 ± 11,711 mm³ after 14a). In addition, significantly higher wear was observed after 14 years with gold as antagonist compared to other materials (p ≤ 0.03). The wear behavior of IPS Empress^® ceramics demonstrates clinically acceptable long-term outcomes, with abrasion characteristics exhibiting stabilization over time. Full article

Objectives: To employ artificial intelligence (AI) to automatically measure bone mineral density (BMD) and intramuscular fat in computed tomography (CT) images of patients with fractures and explore the association between these parameters and fracture healing. Methods: This retrospective study included patients who underwent baseline CT scans for rib fracture diagnosis and follow-up CT scans for fracture healing assessment at our hospital between 2012 and 2023. The volumetric BMD of the entire first lumbar vertebra (L1) and the paraspinal intramuscular fat area (PIFA) at the midsection of L1 in the baseline CT were extracted using AI. The primary outcomes, including callus formation, volume increase, and poor healing, and logistic regression were used to analyze the relationships between BMD and PIFA with primary outcomes. Results: Overall, 297 fractures from 53 patients (24 males; mean age: 53.83 ± 10.86 years) were included in this study. In multivariate regression analysis, a 1 standard deviation (SD) decrease in BMD was identified as an independent prognostic factor for reduced callus formation (odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.50–0.97), diminished volume increase (OR = 0.70, 95% CI = 0.51–0.96), and elevated poor fracture healing at follow-up (OR = 2.08, 95% CI = 1.38–3.13). Similarly, a 1 SD increase in PIFA was an independent prognostic factor for reduced callus formation (OR = 0.24, 95% CI = 0.16–0.37), diminished volume increase (OR = 0.33, 95% CI = 0.23–0.49), and elevated poor fracture healing at follow-up (OR = 2.09, 95% CI = 1.50–2.93). Therefore, a model combining BMD, PIFA, and clinical characteristics significantly outperformed a model that included only clinical characteristics in predicting callus formation, volume increase, and poor fracture healing, with areas under the curve of 0.790, 0.749, and 0.701, respectively (all p < 0.001). Conclusions: BMD and PIFA can be used as early predictors of fracture healing outcomes and can help clinicians select appropriate interventions to prevent poor healing. Full article

Background: We evaluated the utility of HNSCC LN R2* relaxation times to infer the oxygenation status of LN non-invasively at baseline and when breathing air and 100% oxygen to predict chemoradiotherapeutic locoregional response at 2 years. Hypoxia within LNs has been associated with poorer outcomes following CRT. Deoxyhaemoglobin decreases MRI transverse relaxation time (T2*) (lengthening inverse, R2*). Methods: A total of 54 patients underwent 1.5T-MRI before CRT. Conventional MR sequences were supplemented with T2* sequences breathing both air and 100% oxygen; pathological nodes identified in consensus were volumetrically contoured to T2* parametric maps. Results: Patients followed-up with for >2 years were categorised by multidisciplinary consensus into post-therapy complete local response (CR; n = 32/54) and local nodal disease relapse (RD; n = 22/54). Our data demonstrated, by R2*, that nodes that sustained post-therapy CR are significantly more hypoxic compared with relapsing nodes and paradoxically demonstrate a significant increase in hypoxia on 100% oxygen. Pre-treatment LN short axis diameter, various qualitative descriptors of malignancy, and quantitative DWI were not useful in discriminating successful response to CRT. Conclusions: This study demonstrates that a significant differential response to 100% oxygen and higher baseline R2* LN measurements could be exploited in risk stratification prior to CRT, and future work could be directed towards understanding the contrast mechanisms of R2* imaging, underpinning the observed differences in the context of hypoxia. Full article

Background/Objectives: Early and accurate prediction of stroke severity is crucial for optimizing guided therapeutic decisions and improving outcomes. This study investigates the predictive value of lesion size and functional connectivity for neurological deficits, assessed by the National Institutes of Health Stroke Scale (NIHSS score), in patients with acute or subacute subcortical ischemic stroke. Methods: Forty-four patients (mean age: 68.11 years, 23 male, and admission NIHSS score 4.30 points) underwent high-resolution anatomical and resting-state functional Magnetic Resonance Imaging (rs-fMRI) within seven days of stroke onset. Lesion size was volumetrically quantified, while functional connectivity within the motor, default mode, and frontoparietal networks was analyzed using seed-based correlation methods. Multiple linear regression and cross-validation were applied to develop predictive models for stroke severity. Results: Our results showed that lesion size explained 48% of the variance in NIHSS scores (R² = 0.48, cross-validated R² = 0.49). Functional connectivity metrics alone were less predictive but enhanced model performance when combined with lesion size (achieving an R² = 0.71, cross-validated R² = 0.73). Additionally, left hemisphere connectivity features were particularly informative, as models based on left-hemispheric connectivity outperformed those using right-hemispheric or bilateral predictors. This suggests that the inclusion of contralateral hemisphere data did not enhance, and in some configurations, slightly reduced, model performance—potentially due to lateralized functional organization and lesion distribution in our cohort. Conclusions: The findings highlight lesion size as a reliable early marker of stroke severity and underscore the complementary value of functional connectivity analysis. Integrating rs-fMRI into clinical stroke imaging protocols offers a potential approach for refining prognostic models. Future research efforts should prioritize establishing this approach in larger cohorts and analyzing additional biomarkers to improve predictive models, advancing personalized therapeutic strategies for stroke management. Full article

Background: Intraoperative ultrasound (IOUS) provides real-time imaging during brain tumor surgery but remains underused in brain metastasis resection. This study evaluates the effectiveness of 2D IOUS in improving the extent of resection compared to standard neuronavigation. Methods: We retrospectively analyzed 55 adult patients with brain metastases treated surgically at a single center. Patients were divided into two groups: IOUS-guided surgery (n = 20) and standard neuronavigation (n = 35). Gross total resection (GTR) was defined as the extent of resection > 96%, assessed volumetrically. Statistical analyses included chi-square tests, logistic regression, and ROC curve analysis. Results: GTR > 96% was achieved in 80% of IOUS-guided cases compared to 42.86% in the control group (p = 0.008). IOUS significantly increased the odds of achieving GTR (OR = 5.33, p = 0.011). Larger tumor volume reduced the likelihood of GTR (OR = 0.469, p = 0.025), but this effect was mitigated by IOUS use (interaction OR = 1.986, p = 0.044). The regression model showed excellent discrimination (AUC = 0.930, p < 0.001). Functional outcomes improved postoperatively in both groups. Conclusions: 2D IOUS significantly enhances the extent of resection in brain metastasis surgery, including that for larger tumors. Its accessibility, real-time feedback, and low cost support its wider adoption in neurosurgical practice, especially in settings with limited resources. Full article

Biodegradable vascular stents (BVSs) face challenges related to inadequate mechanical strength, which can lead to adverse clinical outcomes. Improving the mechanical behavior of biodegradable vascular stents through structural design has been extensively explored. However, the corresponding effects of these mechanical enhancements on degradation characteristics remain under-investigated. The present work focuses on examining how different stent design strategies affect the mechanical behavior and degradation characteristics of poly (lactic acid) (PLA) stents. The commercial PLA stent DESolve was adopted, and nine modified stents were constructed based on the geometrical configuration of the DESolve stent. The mechanical properties of the modified stents during radial crimping and three-point bending simulations were thoroughly studied. The degradation dynamics of the stents were characterized by four indices (i.e., mean number average molecular weight, residual volume fraction, mean von Mises stress, and stent diameter). The results indicated that both the widening ratio and direction affected the mechanical performance of the stents by increasing the radial stiffness and radial strength, minimizing recoil%, and decreasing the bending flexibility. Although the widening direction had a relatively minor influence on stent degradation, the associated increase in material volume contributed to an improved volumetric integrity and enhanced lumen preservation. This study established a theoretical basis for evaluating both the mechanical and degradation behaviors of PLA stents, offering valuable insights for future structural design optimization. Full article

Optical coherence tomography (OCT) is a non-invasive imaging technique that provides high-resolution, real-time visualization of soft and hard periodontal tissues. It offers micrometer-level resolution (typically ~10–15 μm) and a scan depth ranging from approximately 0.5 to 2 mm, depending on tissue type and system configuration. The field of view generally spans a few millimeters, which is sufficient for imaging gingiva, sulcus, and superficial bone contours. Over the past two decades, its application in periodontology has gained increasing attention due to its ability to detect structural changes in gingival and alveolar tissues without the need for ionizing radiation. Various OCT modalities, including time-domain, Fourier-domain, and swept-source OCT, have been explored for periodontal assessment, offering valuable insights into tissue morphology, disease progression, and treatment outcomes. Recent innovations include the development of three-dimensional (3D) OCT imaging and OCT angiography (OCTA), enabling the volumetric visualization of periodontal structures and microvascular patterns in vivo. Compared to conventional imaging techniques, such as radiography and cone beam computed tomography (CBCT), OCT offers superior soft tissue contrast and the potential for dynamic in vivo monitoring of periodontal conditions. Recent advancements, including the integration of artificial intelligence (AI) and the development of portable OCT systems, have further expanded its diagnostic capabilities. However, challenges, such as limited penetration depth, high costs, and the need for standardized clinical protocols, must be addressed before widespread clinical implementation. This narrative review provides an updated overview of the principles, applications, and technological advancements of OCT in periodontology. The current limitations and future perspectives of this technology are also discussed, with a focus on its potential role in improving periodontal diagnostics and personalized treatment approaches. Full article

Background: PSMA PET/CT imaging has become a cornerstone in the management of prostate cancer, particularly in the setting of biochemical recurrence (BCR). While semi-quantitative parameters such as SUVmean have been evaluated as prognostic biomarkers in metastatic castration-resistant prostate cancer (mCRPC), particularly after the VISION trial, the prognostic role of volumetric measures such as Total Molecular Volume (TMV) remain largely unexplored, especially in earlier stages of the disease such as in biochemical recurrence following primary treatment. Methods: This retrospective monocentric study included 84 patients with BCR who underwent PSMA PET/CT imaging between 2020 and 2021 using either [⁶⁸Ga]Ga-PSMA-11(Ga-PSMA) or [¹⁸F]-PSMA-1007 (F-PSMA) as tracers. Total tumor burden was assessed through manual 3D segmentation to derive whole-body Total Molecular Volume (wb TMV) and Total Lesion PSMA (wb TL-PSMA). Clinical and imaging variables were correlated with overall survival (OS) and progression-free survival (PFS) using Cox regression models. Kaplan–Meier analyses were performed based on wb TMV and thresholds determined by the Youden index. Results: A PSMA PET/CT correlation for BCR was identified in 69% of patients, with comparable detection rates between tracers (Ga-PSMA 67% vs. F-PSMA 63%, p = 0.7). A higher wb TMV was significantly associated with worse OS (HR 2.20, p < 0.001) and PFS (HR 2.01, p < 0.001) in univariable analyses. In multivariable models, log₂(wb TMV) remained an independent prognostic factor for PFS (HR 1.78, p = 0.005). Patients with log₂(wb TMV) > 2.87 exhibited significantly poorer survival outcomes. A PSA at diagnosis > 17 ng/mL also predicted shorter PFS. Conclusions: Tumor segmentation from PSMA PET/CT imaging provides powerful prognostic information in patients with biochemical recurrence of prostate cancer, independently of the tracer used. The wb TMV represents a promising volumetric biomarker for future risk stratification and therapeutic decision-making, particularly in earlier stages of prostate cancer progression, where predictive imaging biomarkers remain largely undefined. Full article

Background: Hyaluronic acid (HA) has emerged as a favored adjunct to restore volume after blepharoplasty and is very effective in the treatment of postoperative hollowness, sagging, and asymmetry. Its efficacy, rate of complications, and optimal injection technique are different in different clinical studies. Hyaluronidase has been studied by diverse methods in the treatment of HA complications, including chronic edema and surgical distortion. This study critically evaluated the efficacy, safety, and technical aspects of HA in the context of blepharoplasty outcomes. Methods: A systematic review was performed to evaluate the use of HA and hyaluronidase for post-blepharoplasty volume rejuvenation and the treatment of complications. Studies describing HA injection technique, time interval between blepharoplasty and injection, volumetric maintenance, complication rates, esthetic and functional results, and patient satisfaction scores were considered. Risk of bias was estimated with the ROBINS-I tool. Results: Sample sizes across the five included studies ranged from 5 to 109 patients, and follow-up intervals ranged from 1 month to 7 years. The age of patients ranged from 31 to 76 years, and females accounted for 86% of the participants in some studies. Injection of HA successfully restored meaningful volume, with retention persisting for over 12 months in the majority of cases. HA preoperative injection caused significant patient satisfaction in a short duration and was not associated with severe complications; delayed injection caused slight distortions in some revision operations. Lipofilling showed a reduced rate of complications (12%) compared with isolated blepharoplasty (20%), suggesting its utility as an adjuvant procedure of volume restoration. Hyaluronidase successfully treated recalcitrant edema, with improvements ranging from 50% to 100%, while the application of adjuvant RF microneedling caused complete remission (100%) in subjects with multiple treatments. The application of ultrasound imaging made measurements more precise, although methods of clinical assessment were significantly heterogeneous among the studies. Conclusions: HA displayed efficacy in terms of efficient volume restoration after blepharoplasty, especially when technique, time, and filler selection are meticulously optimized. In comparison to lipofilling, HA is seen as somewhat safer because of its reversibility and lower likelihood of adverse vascular events. Nonetheless, considerable variability in filler type, amount, timing of administration, and result evaluation constrains conclusive clinical recommendations. The use of hyaluronidase is an effective remedial approach for overcorrection or ongoing edema. Full article

Background: The geriatric nutritional risk index (GNRI), a composite metric of serum albumin and body weight, has emerged as a prognostic tool in various cancers. However, its relevance in nasopharyngeal carcinoma (NPC) patients treated with volumetric modulated arc therapy (VMAT) remains unexplored. The aim of this study was to assess the effect of the GNRI in the prediction of the prognosis of nasopharyngeal carcinoma in the era of VMAT. Methods: This retrospective study analyzed 498 newly diagnosed, non-metastatic NPC patients treated with VMAT between 2010 and 2011. The GNRI was calculated using serum albumin and body weight ratios, with receiver operating characteristic (ROC) curve analysis determining its optimal prognostic cutoff. Patients were stratified into training (70%) and validation (30%) cohorts. Cox regression identified independent prognostic factors, which were integrated into a nomogram predicting 3- and 5-year overall survival (OS). Model performance was assessed via the concordance index (C-index), calibration curves, and decision curve analysis (DCA). Results: In the study, 348 patients were included in the training cohort and 150 patients were included in the validation cohort according to a ratio of 7:3. The median follow-up was 68 months, with 5-year OS rates of 79.3%. A GNRI > 102 independently predicted improved survival (HR = 0.64; p = 0.044), alongside tumor volume, age, and N-stage. The nomogram demonstrated strong discrimination (C-index: 0.757–0.762 for training; 0.737–0.744 for validation) and calibration, aligning closely with observed survival. DCA confirmed superior clinical utility over default strategies. NPC patients treated with VMAT with a high GNRI, female sex, and a lower N-stage exhibited significantly better OS (p < 0.05). Conclusions: The GNRI is a robust prognostic marker for NPC patients receiving VMAT, reflecting the interplay of nutrition, inflammation, and treatment response. The validated nomogram provides a practical tool for individualized risk stratification, enhancing clinical decision-making in the era of precision radiotherapy. Full article

Background and Objectives: Adequate soft tissue thickness and keratinized mucosa are essential for the long-term health and esthetics of the peri-implant area. A porcine acellular dermal matrix (PADM) has shown promise in augmenting soft tissue, but reliable fixation remains a challenge. Materials and Methods: This case series describes the use of a PADM fixed with resorbable magnesium screws (NOVAMag^®) in three patients requiring peri-implant soft tissue augmentation. The grafts were stabilized with magnesium screws on the buccal side. The clinical outcomes were evaluated over a period of 3–6 months using STL imaging and direct measurements. Results: All patients showed an improvement in their mucosal volume and keratinization. The mean vertical increase in soft tissue was 0.87 ± 0.16 mm and the mean horizontal increase was 1.00 ± 0.13 mm. The mucosal thickness increased from a baseline value of 1.0–1.2 mm to 1.9–2.1 mm, and the width of the keratinized mucosa improved by an average of 1.0 mm. No complications were observed, and in all cases there was tension-free healing and esthetic results. Conclusions: A PADM in combination with resorbable magnesium fixation screws offers a predictable and minimally invasive solution to improve peri-implant soft tissue with favourable short-term volumetric and esthetic results. Full article