Search Results (376)

The robust detection of small targets is crucial in infrared (IR) search and tracking applications. Considering that many state-of-the-art (SOTA) methods are still unable to suppress various edges satisfactorily, especially under complex backgrounds, an effective infrared small target detection algorithm inspired by modified fast saliency and the weighted guided image filter (WGIF) is presented in this paper. Initially, the fast saliency map modulated by the steering kernel (SK) is calculated. Then, a set of edge-preserving smoothed images are produced by WGIF using different filter radii and regularization parameters. After that, utilizing the fuzzy sets technique, the background image is predicted reasonably according to the results of the saliency map and smoothed or non-smoothed images. Finally, the differential image is calculated by subtracting the predicted image from the original one, and IR small targets are detected through a simple thresholding. Experimental results on four sequences demonstrate that the proposed method can not only suppress background clutter effectively under strong edge interference but also detect targets accurately with a low false alarm rate. Full article

Background: Arteriovenous malformations (AVMs) are rare vascular anomalies that can cause intracerebral hemorrhage, particularly in pediatric patients. Low-flow AVMs may not be visualized on initial non-invasive imaging modalities such as MR angiography. Methods: We report a 6-year-old boy who presented with intracerebral hemorrhage and initially had no detectable vascular anomaly on MR angiography and MR venography. Two years later, he was re-admitted with a recurrent hemorrhage. Repeating MR angiography again failed to reveal any vascular pathology. Results: Digital subtraction angiography (DSA) performed later identified a grade 3 low-flow AVM in the left posterior temporal region. The patient underwent successful endovascular treatment with no subsequent neurological deficits. Conclusions: This case underscores the limitations of MR angiography in detecting low-flow AVMs and highlights the essential role of DSA in the definitive diagnosis and management of unexplained intracerebral hemorrhages in pediatric patients. Full article

Background/Objectives: Digital prosthodontics increasingly utilize both additive (3D printing) and subtractive Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), yet comprehensive comparisons remain limited. This scoping review evaluates their relative performance across prosthodontic applications. Methods: Systematic searches (PubMed, Scopus, Web of Science, Embase, 2015–2025) identified 28 studies (27 in vitro, 1 retrospective). Data were extracted on accuracy, efficiency, materials, and outcomes. Results: CAD/CAM milling demonstrated superior accuracy for fixed prostheses, with marginal gaps for milled zirconia (123.89 ± 56.89 µm), comparable to optimized 3D-printed interim crowns (123.87 ± 67.42 µm, p = 0.760). For removable prostheses, milled denture bases achieved a trueness of 65 ± 6 µm, while SLA-printed dentures post-processed at 40 °C for 30 min showed the lowest root mean square error (RMSE) (30 min/40 °C group). Three-dimensional printing excelled in material efficiency (<5% waste vs. milling > 30–40%) and complex geometries, such as hollow-pontic fixed dental prostheses (FDPs) (2.0 mm wall thickness reduced gaps by 33%). Build orientation (45° for crowns, 30–45° for veneers) and post-processing protocols significantly influenced accuracy. Milled resins exhibited superior color stability (ΔE00: 1.2 ± 0.3 vs. 3D-printed: 4.5 ± 1.1, p < 0.05), while 3D-printed Co-Cr frameworks (SLM) showed marginal fits of 8.4 ± 3.2 µm, surpassing milling (130.3 ± 13.8 µm). Digital workflows reduced chairside time by 29% (154.31 ± 13.19 min vs. 218.00 ± 20.75 min). All methods met clinical thresholds (<120 µm gaps). Conclusions: Milling remains preferred for high-precision fixed prostheses, while 3D printing offers advantages in material efficiency, complex designs, and removable applications. Critical gaps include long-term clinical data and standardized protocols. Future research should prioritize hybrid workflows, advanced materials, and AI-driven optimization to bridge technical and clinical gaps. Full article

Marine oil spills cause significant environmental damage worldwide. Marine radar imagery is used for oil spill detection. However, the rapid attenuation of backscatter intensity with increasing distance limits detectable coverage. A multi-stage image enhancement framework integrating background clutter fitting subtraction, Multi-Scale Retinex, and Gamma correction is proposed. Experimental results using marine radar images sampled in the oil spill incident in Dalian 2010 are used to demonstrate the significant improvements. Compared to Contrast-Limited Adaptive Histogram Equalization and Partially Overlapped Sub-block Histogram Equalization, the proposed method enhances image contrast by 24.01% and improves the measurement of enhancement by entropy by 17.11%. Quantitative analysis demonstrates 95% oil spill detection accuracy through visual interpretation, while significantly expanding detectable coverage for oil extraction. Full article

Background/Objectives: Assessment of a novel deep-learning (DL)-based T1w volumetric interpolated breath-hold (VIBE_DL) sequence in breast MRI in comparison with standard VIBE (VIBE_Std) for image quality evaluation. Methods: Prospective study of 52 breast cancer patients examined at 1.5T breast MRI with T1w VIBE_Std and T1 VIBE_DL sequence. T1w VIBE_DL was integrated as an additional early non-contrast and a delayed post-contrast scan. Two radiologists independently scored T1w VIBE _Std/DL sequences both pre- and post-contrast and their calculated subtractions (SUBs) for image quality, sharpness, (motion)–artifacts, perceived signal-to-noise and diagnostic confidence with a Likert-scale from 1: Non-diagnostic to 5: Excellent. Lesion diameter was evaluated on the SUB for T1w VIBE_Std/_DL. All lesions were visually evaluated in T1w VIBE_Std/_DL pre- and post-contrast and their subtractions. Statistics included correlation analyses and paired t-tests. Results: Significantly higher Likert scale values were detected in the pre-contrast T1w VIBE_DL compared to the T1w VIBE_Std for image quality (each p < 0.001), image sharpness (p < 0.001), SNR (p < 0.001), and diagnostic confidence (p < 0.010). Significantly higher values for image quality (p < 0.001 in each case), image sharpness (p < 0.001), SNR (p < 0.001), and artifacts (p < 0.001) were detected in the post-contrast T1w VIBE_DL and in the SUB. SUB_DL provided superior diagnostic certainty compared to SUB_Std in one reader (p = 0.083 or p = 0.004). Conclusions: Deep learning-enhanced T1w VIBE_DL at 1.5T breast MRI offers superior image quality compared to T1w VIBE_Std. Full article

Pulmonary dynamic contrast-enhanced (DCE) MRI is clinically useful for assessing pulmonary perfusion, but its signal-to-noise ratio (SNR) is limited. A self-supervised learning network-based plug-and-play (PnP) denoising model was developed to improve the image quality of pulmonary perfusion MRI. A dataset of patients with suspected pulmonary diseases was used. Asymmetric pixel-shuffle downsampling blind-spot network (AP-BSN) training inputs were two-dimensional background-subtracted perfusion images without clean ground truth. The AP-BSN is incorporated into a PnP model (PnP-BSN) for balancing noise control and image fidelity. Model performance was evaluated by SNR, sharpness, and overall image quality from two radiologists. The fractal dimension and k-means segmentation of the pulmonary perfusion images were calculated for comparing denoising performance. The model was trained on 29 patients and tested on 8 patients. The performance of PnP-BSN was compared to denoising convolutional neural network (DnCNN) and a Gaussian filter. PnP-BSN showed the highest reader scores in terms of SNR, sharpness, and overall image quality as scored by two radiologists. The expert scoring results for DnCNN, Gaussian, and PnP-BSN were 2.25 ± 0.65, 2.44 ± 0.73, and 3.56 ± 0.73 for SNR; 2.62 ± 0.52, 2.62 ± 0.52, and 3.38 ± 0.64 for sharpness; and 2.16 ± 0.33, 2.34 ± 0.42, and 3.53 ± 0.51 for overall image quality (p < 0.05 for all). PnP-BSN outperformed DnCNN and a Gaussian filter for denoising pulmonary perfusion MRI, which led to improved quantitative fractal analysis. Full article

Background/Objectives: The increase in life expectancy and the share of the elderly population has the effect of increasing the number of osteoporotic hip fractures. At the same time, the number of total hip arthroplasty (THA) interventions is continuously increasing. The objective of this study is to investigate the incidence rates of hip fractures during the period 2008–2019, in Romania, among people who are at least 40 years old, as well as to determine the extent to which the increase in the prevalence of people who have undergone THA has affected the incidence of hip fractures, given that the operated hip no longer presents a risk of fracture. Methods: We extracted the information, between 2008 and 2019, from nationwide retrospective studies about the incidence and time trend of hip fractures in Romania. Information on primary THA interventions during the period 2001–2019 was obtained from the Romanian Arthroplasty Register (RAR). We obtained the population size, by gender and age groups, from the reports of the National Institute of Statistics. For the period 2008–2019, we calculated the standardized annual hip fracture incidence rates by sex and by age. Given that each person has two hips at risk of fracture, we calculated hip fracture rates in a scenario without THA interventions. For this, we subtracted 0.5 people from the at-risk population for each prevalent hip prosthesis. Thus, we revealed the effects of decreasing fracture rates due to having hip prostheses. Results: From 2008 to 2019, age-standardized incidence rates of hip fractures increased by 10.8% in women, and by 2.8% in men. By excluding hips being replaced with prostheses in the at-risk population, we obtained higher hip fracture incidence rates. These recorded values were considerably higher for the elderly population. The variation in hip fracture rates during the observed period was 10.16% (9.76% in women and 11.68% in men) lower due to the increased prevalence of hip prostheses. Conclusions: Although the incidence of hip fractures has continued to rise, the growing number of people who have undergone THA and are living with hip prostheses has helped to blunt this increase. Full article

Background: To examine the association between allostatic load and the progression of multimorbidity and the role of socioeconomic factors among older Americans. Methods: Data from the Health and Retirement Study (HRS), a longitudinal study of older American adults, were used. Data were included from waves 8 (2006), 10 (2010), 11 (2012), and 13 (2016). Self-reported diagnoses of five chronic conditions (diabetes, heart disease, lung diseases, cancer, and stroke) indicated multimorbidity and were dichotomised to reflect having two or more conditions versus one or fewer. Multimorbidity in 2006 was subtracted from that in 2016 to calculate ten-year change in multimorbidity. Sociodemographic data (age, gender, education, and wealth) were from wave 8 (2006). Behaviours (physical activity and smoking) were from wave 10 (2010). Allostatic load, indicated by five biomarkers (waist circumference, high blood pressure, glycosylated haemoglobin, high-density lipoprotein, and c-reactive protein), was from wave 11 (2012). Structural Equation Modelling (SEM) was used to assess the longitudinal association between the aforementioned factors and the incidence of multimorbidity in 2016. Results: Given that allostatic load was assessed in a subsample of HRS, 8222 were excluded for lack of relevant data. A total of 3336 participants were included in the final analysis. The incidence of multimorbidity in 2016 was 19%. Allostatic load in 2012 was significantly associated with the incidence of multimorbidity in 2016 (estimate 0.10, 95% Confidence Interval (CI) 0.07, 0.14); in other words, for an additional marker of allostatic load, there was an average 0.1 change in the incidence of multimorbidity. Wealth and education (2006) were indirectly associated with multimorbidity through allostatic load and behaviours. Smoking (2010) was positively associated with multimorbidity in 2016, while physical activity showed a negative association. Conclusions: Biological markers of stress indicated by allostatic load were associated with multimorbidity. Adverse socioeconomic conditions appear to induce allostatic load and risk behaviours, which impact the progression of multimorbidity. Full article

Background/Objectives: The course of treatment for renal artery stenosis following renal transplantation depends on the severity of the condition. Mild cases are typically managed medically, while more significant stenosis with flow limitation and graft dysfunction requires percutaneous intervention. Surgical treatment is generally reserved as a last resort. This study aimed to evaluate the outcomes of interventional radiology in managing renal artery stenosis at our transplant center. Methods: The electronic medical records of patients who underwent renal transplantation at our center between January 2020 and December 2024 were reviewed to identify cases of renal artery stenosis and their subsequent management through interventional radiology. Sociodemographic and clinical data were collected for both recipients and donors. Data analysis was performed using SPSS version 26. Results: Out of the total 368 patients who received renal allograft at our center from January 2020 to December 2024, 25 patients were confirmed with duplex ultrasound to have renal artery stenosis. The majority of affected patients were African American, had Class I Obesity and presented with cardiovascular co-morbidities. The mean time from transplant to the diagnosis of RAS was 4.25 (SD ± 3.81) months. The mean serum creatinine level at presentation was 2.54 (SD ± 1.21 mg/dL). All 25 patients underwent digital subtraction angiography, and 24 patients were confirmed to have renal artery stenosis requiring further intervention. The creatinine levels at one week, three months and one year post-intervention were 2.12 (SD ± 1.00), 1.83 (SD ± 0.63) and 2.15 (SD ± 1.68) mg/dL, respectively. Conclusions: Percutaneous interventional treatment for renal artery stenosis is associated with improvements in hemodynamic parameters and the stabilization of allograft function. Follow-up is needed to monitor for the potential occurrence of restenosis. Full article

Microfluidic modulation spectroscopy-infrared (MMS) offers a label-free, high-sensitivity approach for quantifying changes in protein secondary structures under native solution conditions. MMS subtracts the solvent backgrounds from sample signals by alternately flowing proteins and matched buffers through a microfluidic chamber, yielding clear amide I spectra from microliter volumes. In this study, we validated MMS on canonical globular proteins, bovine serum albumin, mCherry, and lysozyme, demonstrating accurate detection and resolution of α-helix, β-sheet, and mixed-fold structures. Applying MMS to the intrinsically disordered protein Tau, we detected environment-driven shifts in transient conformers: both the acidic (pH 2.5) and alkaline (pH 10) conditions increased the turn/unordered structures and decreased the α-helix content relative to the neutral pH, highlighting the charge-mediated destabilization of the labile motifs. Hyperphosphorylation of Tau yielded a modest decrease in the α-helical fraction and an increase in the turn/unordered structures. Comparison of monomeric and aggregated hyperphosphorylated Tau revealed a dramatic gain in β-sheet and a loss in turn/unordered structures upon amyloid fibril formation, confirming MMS’s ability to distinguish disordered monomers from amyloids. These findings establish MMS as a robust platform for detecting protein secondary structures and monitoring aggregation pathways in both folded and disordered systems. The sensitive detection of structural transitions offers opportunities for probing misfolding mechanisms and advancing our understanding of aggregation-related diseases. Full article

Background/Objectives: Perimesencephalic subarachnoid hemorrhage (pmSAH) is generally considered to be a benign variant of spontaneous SAH. However, in rare cases, an underlying aneurysm may be present, altering both clinical management and prognosis. The aim of this study was to evaluate the prognostic impact of aneurysmal pathology in patients presenting with perimesencephalic hemorrhage, focusing on the occurrence of complications and functional outcomes. Methods: This single-center, retrospective study included 77 patients diagnosed with perimesencephalic hemorrhage between 2012 and 2022. Clinical and radiological data were extracted, including demographics, risk factors, complications (hydrocephalus, vasospasm, and delayed cerebral ischemia (DCI)), and outcome scores (Glasgow Outcome Scale (GOS) and modified Rankin scale (mRS) at discharge). Patients were divided into two groups based on the presence or absence of an aneurysm confirmed through digital subtraction angiography (DSA). Results: Of the 77 patients, 7 (9.1%) were found to have an aneurysm. While rates of complications such as hydrocephalus and DCI were higher in the aneurysm group, these differences did not reach statistical significance. However, patients with aneurysms had significantly worse functional outcomes, with higher mRS and lower GOS scores at discharge. Logistic regression confirmed the presence of aneurysms as an independent factor associated with poor outcomes (OR = 21.6; 95% CI: 1.00−467.3; p = 0.050), while other variables such as age, sex, and World Federation of Neurosurgical Societies (WFNS) score were not statistically significant. ROC analysis showed moderate discriminative power of aneurysm presence for poor outcomes (AUC = 0.72). Conclusions: The presence of an aneurysm, although rare in pmSAH, significantly worsens functional outcomes. These findings highlight the necessity of early and sensitive vascular diagnostics—particularly DSA—to reliably exclude aneurysms. Differentiating between aneurysmal and non-aneurysmal perimesencephalic bleeding is essential not only for clinical decision-making but also for optimizing resource allocation in neurocritical care. Full article

Based on the concept of an equivalent eddy current, anomaly field inversion provides an efficient and rapid inversion method for borehole transient electromagnetic (BHTEM) measurements. It enables the utilization of the equivalent eddy current to rapidly process and interpret BHTEM data. This method allows for the accurate determination of the central position and spatial distribution of anomalies. However, the equivalent eddy current method is solely applicable to the inversion of the anomaly field. Given that the measured data frequently contain strong background field information, it is challenging to directly apply the equivalent eddy current approach to the inversion and interpretation of the measured data. To address the aforementioned issues, in this study, we innovatively put forward a method. Specifically, we utilize the response of the layered earth to simulate the background field and subtract the background field from the measured data through the “difference method” to extract the anomaly field. Subsequently, by integrating the equivalent eddy current method, the inversion of the anomaly field was accomplished. Eventually, a rapid quantitative inversion and interpretation of BHTEM data were achieved. We applied this approach to extract the pure anomaly from the measured data of the zk506 borehole in the Baishiquan mining area, Xinjiang, and then conducted equivalent eddy current inversion. The spatial position and distribution characteristics of the concealed ore bodies near the zk506 borehole were successfully pinpointed. Validation by the zk507 and zk508 boreholes confirmed that the main anomaly of the nickel ore body is positioned in the southeast of the boreholes, dipping northwestward. This outcome validates the accuracy of the BHTEM inversion interpretation and rectifies the geological understanding obtained from the zk506 single borehole. It demonstrates the effectiveness and significance of the pure anomaly extraction based on the layered-earth model and equivalent eddy current inversion in the exploration of high-conductivity sulfide ores. Full article

Background/Objectives: Biportal endoscopic spine surgery (BESS) is one of the minimally invasive spine surgery techniques. BESS has several advantages, such as better visualization, less muscle injury, early rehabilitation, etc. Due to its clear visualization, delicate intraoperative hemostasis of the bleeding foci, including cancellous bone and small epidural vessels, can be achieved. Therefore, some authors have reported that BESS resulted in less intraoperative visible blood loss (VBL) compared to conventional open surgery. However, it is difficult to analyze the exact amount of intraoperative blood loss because of the continuous normal saline irrigation. In addition, hidden blood loss (HBL) tends to be overlooked, and the amount of HBL might be larger than expected. We aim to calculate the amount of HBL during BESS and to compare our findings with convention open surgery. Methods: We retrospectively obtained the clinical data of patients that underwent lumbar central decompression from July 2021 to June 2024. Patients were divided into two groups: the BESS group that underwent biportal endoscopic lumbar decompression, and the open surgery group that underwent open decompression. Both groups used unilateral laminotomy and bilateral decompression techniques. Total blood loss (TBL) using preoperative and postoperative change in hematocrit (Hct) was measured using Gross’s formula and the Nadler equation. Since TBL consists of VBL and HBL, HBL was calculated by subtracting the VBL measured intraoperatively from TBL. Results: A total of sixty-six patients in the BESS group and seventeen patients in the open surgery group were included in the study. The TBL was 247.16 ± 346.88 mL in the BESS group and 298.71 ± 256.65 mL in the open surgery group, without significant difference (p = 0.569). The calculated HBL values were 149.44 ± 344.08 mL in the BESS group and 171.42 ± 243.93 mL in the open surgery group. The HBL in the BESS group was lower than the HBL in the open surgery group, without significant difference (p = 0.764). Conclusions: The TBL and HBL during lumbar central decompression were smaller in patients who underwent BESS compared to those who underwent open surgery. While TBL was significantly lower in BESS, HBL did not show statistical significance between the two groups. HBL during BESS should not be neglected, and related hemodynamics should be considered postoperatively. Full article

An accurate thermal measurement of low-frequency stimulation (LFS) pads for thermotherapy was investigated using background subtraction (BGS) methods. The safety of LFS thermal pads must be investigated to prevent low-temperature burns (LTBs), because they frequently contact the sensitive skin in neck, shoulder and abdominal regions. The thermal measurement was based on thermal imaging using the active region-of-interest (ROI) from a foreground. The shape of the LFS thermal pad consists of complicated curves, thus it is difficult to extract the foreground using conventional shapes of ROIs. We proposed the foreground extraction using background subtraction (BGS) and digital and morphological filters to time-variant thermal images. The foreground extraction was implemented using open sources and experimented for abdominal, cervical and patellar pads. The results showed that the foreground can be separated from background regardless of the size, position, orientation and shape of the pad. The thermal characteristics of the LFS thermal pads were evaluated from the complicated shapes of the foreground with high accuracy. This study demonstrated that standard deviation of pixel history (SDPH) is a simple method for the BGS, but the SDPH is useful to find the safety risk of LTBs and prevent them in advance. The results also showed that the proposed SDPH was simple but had remarkable accuracy compared with the conventional BGS methods. These BGS methods are expected to increase the reliability of products used on the human body. Further, the BGS methods can be used to inspect the temperatures of static products in industrial processes. Full article

Background/Objectives: Aortic stiffness is a strong independent factor in cardiovascular outcomes. The method of choice for evaluating aortic stiffness is the measurement of aortic pulse wave velocity (PWV). Endovascular aortic repair (EVAR) increases aortic rigidity and thus aortic stiffness. The aim of this study is to investigate the correlation between endograft length and post-operative increases in PWV in patients with abdominal aortic aneurysms (AAAs) subjected to EVAR. Methods: A prospective observational study enrolling 107 patients from February to December 2025 was conducted. Patient demographics and comorbidities were recorded. The length of the endografts was calculated by studying computed tomography angiograms (CTAs) and digital subtraction angiographies (DSAs) of the patients. PWV was measured pre-operatively and post-operatively during the first 24 h after EVAR, and the difference in PWV (dPWV) was calculated. Results: The mean age of the patients was 72 ± 7.5 years, and 93.5% of them were males. The mean transverse AAA diameter was 5.7 ± 1.1 mm, and the mean endograft length was 169.7 ± 26.9 mm. An extension to the external iliac artery was deployed in 10 patients (9.3%). A strong positive correlation was observed between dPWV and endograft length, indicating that each additional 1 mm in graft length corresponded to a 0.541% increase in dPWV. Patients with an extension to external iliac arteries exhibited a significantly higher mean dPWV (9.95 ± 2.08% vs. 27.12% ± 12.15%, t = −4.463, p = 0.002). No statistically significant differences in dPWV between the different endograft types were found (p = 0.74). Conclusions: Endograft length is strongly related to PWV elevation during the immediate post-operative time after EVAR, especially when the endograft is extended to the external iliac arteries. Full article