Search Results (286)

This report describes a unique constellation of accessory ossicles, highlighting their anatomical, clinical, and radiological significance. A 43-year-old female undergoing imaging for suspected fracture was evaluated using multi-detector computed tomography (MDCT) with 1.25 mm slice thickness. Multiplanar reconstructions (axial, coronal, sagittal) and three-dimensional volume-rendered images were analyzed. CT imaging revealed the coexistence of an os subfibulare and a tripartite os naviculare. Multiplanar and three-dimensional reconstructions confirmed the presence and configuration of variants. The combination of supernumerary bones and a multipartite ossicle represents an exceedingly uncommon anatomical presentation. This case illustrates an exceptional coexistence of multiple accessory ossicles, including an exceedingly rare tripartite os naviculare. Thorough radiological evaluation using MDCT and multiplanar reconstructions is essential for accurate identification and differentiation from fractures or other pathology. Full article

Background/Objectives: Differentiating mediastinal lymphadenopathy associated with lung cancer from sarcoidosis remains a clinical challenge because of overlapping imaging findings. This study evaluated whether CT-derived radiomic features, alone and in combination with clinical variables, could support the non-invasive differentiation of these two entities. Methods: In this retrospective single-center study, 204 histopathologically confirmed mediastinal lymph nodes were analyzed. A total of 107 radiomic features were extracted from manually segmented contrast-enhanced thoracic CT images. Multiple feature selection methods, dimensionality reduction techniques, and machine learning classifiers were evaluated using patient-level five-fold cross-validation. Additional clinical-only, combined clinical–radiomic, one-node-per-patient sensitivity, and exploratory interobserver feature stability analyses were performed. Results: Among radiomics-only models, LASSO achieved the highest ROC–AUC of 0.9108, whereas ElasticNet achieved the highest accuracy of 81.20%. The clinical-only ensemble model using age, sex, and smoking status showed strong performance, with an accuracy of 94.92% and an ROC–AUC of 0.9733. Selected combined clinical–radiomic models showed numerically higher performance; the combined correlation-filtered ensemble model achieved the highest accuracy of 97.78% and an ROC–AUC of 1.0000. Clinical integration also yielded more compact feature subsets in some methods, as combined LASSO selected 9.6 variables while improving ROC–AUC from 0.9108 to 0.9667 compared with radiomics-only LASSO. In the one-node-per-patient sensitivity analysis, clinical-only and combined models retained high performance, whereas radiomics-only LASSO showed reduced performance. Exploratory interobserver analysis showed moderate reproducibility for only a subset of radiomic features. Conclusions: CT-derived radiomic features may provide complementary information for differentiating mediastinal lymphadenopathy associated with lung cancer from that associated with sarcoidosis. However, clinical variables were highly informative, and the incremental value of radiomics should be interpreted cautiously. Further multicenter studies with external validation, standardized segmentation protocols, and clinically balanced cohorts are required before routine clinical implementation can be recommended. Full article

Background/Objectives: Hypoattenuated leaflet thrombosis (HALT) is a frequent finding after transcatheter aortic valve replacement (TAVR). Although high residual platelet reactivity (HPR) increases thrombotic risk after coronary stent implantation, its role in HALT remains unclear. This study aimed to determine the incidence and predictors of HALT in TAVR patients treated with dual antiplatelet therapy, focusing on the impact of HPR. Methods: This was a prospective, multicenter observational study. Between June 2018 and February 2022 patients with symptomatic severe aortic stenosis undergoing successful TAVR and treated with dual antiplatelet therapy for 3 months were included. Platelet reactivity was assessed 1–3 months post-TAVR using either VerifyNow (72%) or the Multiplate Analyzer (28%). HALT was evaluated using contrast-enhanced multidetector computed tomography. Results: A total of 169 patients were included (mean age 81.5 ± 5 years; 51% female). The incidence of HALT was 22%. Independent predictors of HALT were self-expanding valve (OR 3.05; 95% CI, 1.30–7.14; p = 0.010). Protective factors included larger prosthesis size (OR 0.78; 95% CI, 0.65–0.93; p = 0.007), statin-treated dyslipidemia (OR 0.37; 95% CI, 0.16–0.88; p = 0.024), and higher creatinine clearance (OR 0.98; 95% CI, 0.96–1.00; p = 0.035). HALT incidence was similar in patients with and without HPR (23.7% vs. 33.6%; p = 0.29). No differences in clinical outcomes were observed at 1 year. Conclusions: HALT occurred in nearly one-quarter of TAVR patients treated with dual antiplatelet therapy and was unrelated to platelet reactivity. Valve characteristics, renal function, and statin-treated dyslipidemia were associated with HALT, highlighting the multifactorial nature of its development. Full article

Aphasia is a complex neurological syndrome that includes a multitude of signs and symptoms that describe a patient’s inability to use language (understanding and producing spoken and/or written language) after it has already been acquired, which is caused by cerebral lesions situated in the dominant (left) cerebral hemisphere in right-handed people. Aphasia has a prevalence of 25–30% in acute ischemic stroke (especially in arterial infarcts). In patients who suffered cerebral venous and dural sinuses thrombosis (CVST), aphasia has been noticed in almost 20% of cases, its presence being considered a negative predictive factor. We report the case of a 22-year-old right-handed woman with obesity and active smoking (10 cigarettes/day), undergoing treatment with oral contraceptives who presented to the Emergency Department with an intense headache, resistant to usual analgesic treatment, accompanied by language disorders onset within 24 h. The neurological examination was normal, except for language assessment, which revealed the severe impairment of the repetition domain (she was unable to repeat simple words), and difficulty in naming objects with some hesitations and mild comprehension difficulties (especially in complex orders). She underwent neuroimaging examinations at admission. Native Head Computed Tomography revealed spontaneous hyperdensity (parenchymatous hematoma) in the left temporal lobe. Cranial magnetic resonance imaging (MRI) confirmed venous infarction in the left temporal area and a hypointense signal on MRI T2*SW (susceptibility-weighted) in the region of the left lateral sinus and left jugular vein bulb, which confirmed the thrombosis at this level. Associated cortical vein thrombosis was diagnosed on indirect radiological grounds, since hemorrhagic transformation obscured the direct visualization of the adjacent cortical veins. MR venography was not performed at that time, but instead at the 1-month follow-up, MR venography confirmed the chronic, partial thrombosis of the left lateral sinus and left jugular vein bulb. Laboratory data demonstrated an elevated D-dimer and the presence of homozygosity for MTHFR C677T and PAI-1 4G/4G. Anticoagulation in the form of low-molecular-weight heparin was immediately started, followed by chronic treatment with oral anticoagulant (apixaban) and folic acid. The headaches resolved within three days, and her neurological examination was almost normal: the repetition continued being altered for complex phrases. We did not observe any left lateral sinus thrombosis recurrence, or other extra-cerebral embolic events (deep vein thrombosis or pulmonary embolism) during the follow-up year. The immediate anticoagulation since the admission resulted in a favorable outcome. Taking into consideration our interest in monitoring patients with aphasia secondary to CVST, we also analyzed data from the literature regarding the incidence of conduction aphasia and other aphasic syndromes in this CVST. Due to the limited number of articles identified in the last 21 years (2005–2026) in the literature, we concluded that conduction aphasia is an extremely rare clinical presentation in this kind of pathology and further studies should be conducted in order to identify significant statistical data. Full article

The quantitative measurement of nuclear material hold-up in the process equipment is one of the technical challenges in nuclear material measurement for nuclear facilities. Its results are directly related to the optimization of radiation protection, the criticality safety control of nuclear materials, and the accurate accounting of nuclear material. As a key core equipment in the nuclear material reprocessing process, the precipitation reactor is restricted by the complex on-site environment, compact spatial layout, and continuous operation process, making it difficult for traditional measurement technologies to conduct accurate quantitative analysis of the internal hold-up. To address this issue, this paper proposes a method for measuring and analyzing the hold-up in the precipitation reactor based on the passive neutron counting method. A laboratory model of the precipitation reactor is constructed, and a multi-detector neutron measurement system is developed in this work. By combining Monte Carlo (MC) simulation with experimental calibration of standard point sources, a mathematical model suitable for hold-up measurement of the precipitation reactor is established. Meanwhile, uncertainty analysis of key data was carried out, and the accuracy of the model was verified by operational Pu samples of various masses, effectively reducing the measurement deviation caused by the uneven distribution of hold-up in the equipment and model assumptions. This research provides a more reliable technical reserve and reference paradigm for the measurement of nuclear material hold-up in nuclear facilities. Full article

Primary pulmonary artery sarcoma (PPAS) is a mesenchymal tumor originating from the pulmonary artery, accounting for approximately 0.001–0.003% of all sarcomas. The early clinical symptoms are atypical, and diagnosis is often delayed, making the management of this disease challenging. The widespread availability of multidetector computed tomography (MDCT), ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT), and high-resolution echocardiography has significantly improved the diagnostic capability for PPAS. We herein report a 74-year-old female patient who presented with a 3-week history of exertional dyspnea without an apparent trigger. She had received anti-inflammatory therapy at another hospital for one week. Five days before admission, she experienced right-sided chest pain without apparent cause, which was respiratory-related. On the day of admission, laboratory tests revealed a slight elevation in D-dimer levels. Echocardiography showed an irregular, moderately echogenic mass at the origin of the right pulmonary artery. Enhanced computed tomography (CT) of the chest revealed a filling defect in the right pulmonary artery accompanied by bilateral pleural effusion. The patient was given heparin anticoagulation therapy. To confirm the nature of these lesions, a PET/CT scan was conducted five days after admission, which indicated hypermetabolism in the right pulmonary artery, suggesting primary pulmonary artery sarcoma. Due to the poor efficacy of anticoagulation therapy, the patient continued to experience breath-holding after physical activity. Subsequently, catheter-guided interventional angiography was carried out for pulmonary artery thrombectomy and biopsy, and histopathological examination revealed pulmonary artery sarcoma. Given the patient’s respiratory failure and heart failure, as well as the uncertain efficacy of radiotherapy and chemotherapy, interventional pulmonary artery thrombectomy alleviated the chest pain. Currently, the patient’s overall condition is stable. Full article

Cerebral venous sinus thrombosis (CVST) is a rare form of stroke with heterogeneous clinical presentation and etiological profile. This study aimed to evaluate the demographic, clinical, imaging, etiological, treatment, and outcome characteristics of CVST in a Romanian population. We conducted a retrospective monocentric cohort study including 55 patients diagnosed over a six-year period in a tertiary neurological center. CVST accounted for 1.2% of all stroke cases, with an incidence of 13.75 per million per year. Gender distribution was relatively balanced, differing from international cohorts, and traditional female-specific risk factors were less prominent. Thrombophilia (68.6%) and infections (38.2%) were the most frequent etiologies. Younger patients were more frequently associated with thrombophilia, while a higher inflammatory response was observed in older individuals; additionally, female patients showed a higher prevalence of the MTHFR C677T mutation. Transverse and sigmoid sinuses were the most affected, while cavernous sinus involvement was more frequent than typically reported and associated with infections. At discharge, long-term anticoagulation was recommended in 67.3% of patients, tailored to underlying etiology and risk profile. Outcomes were favorable, with 70–80% achieving a modified Rankin Scale score ≤2 at discharge and over 90% at 90-day follow-up, despite inconsistent correlation with imaging findings. These results highlight the heterogeneous nature of CVST and the need for comprehensive, individualized evaluation and management. Full article

NanoArduSiPM represents a paradigm shift in the ArduSiPM (Architected Detection Unit for Silicon Photomultipliers) roadmap, evolving from a standalone instrument into a high-density modular building block (36 mm × 42 mm × 3 mm, 7 g). This revision does not merely pursue miniaturization; it re-engineers the signal-processing chain to maintain high performance within a scaled-down footprint, enabling the transition from single-unit detection to scalable, distributed multi-detector systems. NanoArduSiPM is based on a three-layer architecture comprising an external scintillator and Silicon Photomultiplier (SiPM) detection module, a dedicated high-speed discrete analog front-end, and a System-on-Chip (SoC) for embedded acquisition and processing. The physical implementation adopts high-integrity PCB routing and rigorous isolation techniques designed to suppress digital–analog coupling, a critical requirement in such a compact form factor. This deterministic layout strategy provides the architectural foundation for time-tagging capabilities, currently under quantitative characterization, by addressing the fundamental sources of signal interference at the hardware level. Beyond hardware integration, NanoArduSiPM introduces the capability for extended firmware functionality, including event tagging via external inputs and the implementation of coincidence and veto logic. This framework supports the acquisition of multiple correlated histograms and allows multiple units to be interconnected on a shared SPI bus. By shifting from standalone operation to a coordinated, hierarchical architecture, NanoArduSiPM enables distributed detection schemes where event selection and correlation are handled natively within the system, reducing the dependency on external data acquisition electronics. The compact modular architecture, together with the high-performance discrete analog front-end and embedded data handling, makes NanoArduSiPM suitable for applications where low mass and low power consumption are critical, targeting applications such as space-based payloads, laboratory instrumentation, remote sensing, and large-scale distributed multi-channel detection systems. While no radiation-tolerance qualification of the complete system has been performed in this work, the microcontroller family used in the design is also available in radiation-tolerant variants, which may support future implementations targeting more demanding radiation environments. Full article

The range of possible inflammatory changes in the oral cavity and in the maxillary and mandibular bones may present with diverse patterns and characteristics in both clinical and radiological evaluation. In most cases, a standard radiological examination, such as dental panoramic radiograph (DPR), has significant limitations in assessing early or complex bone changes associated with chronic bone inflammation. Advanced imaging with multidetector computed tomography or cone-beam computed tomography (MDCT or CBCT) can improve lesion characterization and surgical planning when a detailed evaluation of tooth-bearing structures, tooth apices, cortical plates, and cancellous bone is required. Such imaging allows more detailed assessment of alterations in medullary bone morphology and architecture, as well as identification of possible periosteal reactions adjacent to chronic bone inflammation. Osteomyelitis of the jaws comprises a heterogeneous group of inflammatory bone disorders characterized by variable clinical presentations and a broad spectrum of radiological appearances. Depending on disease chronicity, host factors, and microbial burden, mandibular osteomyelitis may mimic odontogenic tumors, fibro-osseous lesions, or malignant bone pathologies. Quite often, dental treatment affects bone status and condition, leading to unwanted events such as bone inflammation. Imaging plays a central role in diagnosis; however, radiographic findings are often nonspecific, particularly in early or chronic stages. Each case of osteomyelitis underscores the importance of correlating imaging findings with clinical history and highlights the role of repeated imaging in distinguishing inflammatory bone disease from aggressive jaw lesions. This study aims to characterize diverse patterns of chronic mandibular osteomyelitis associated with various prior treatment modalities using CBCT. By presenting a series of illustrative cases from heterogeneous clinical settings, the authors highlight the nonspecific radiographic features and diagnostic challenges inherent in chronic bone inflammation. The focus remains on the interpretation of complex imaging findings rather than a comparative analysis of technical protocols. Full article

Background: Traditional intraoperative sizing for sutureless aortic valves, such as the Corcym Perceval Plus (CPP), often relies on subjective tactile feedback, which can lead to excessive over-sizing. Significant over-sizing is associated with complications like increased trans-prosthetic gradients, valve thrombosis, and conduction disturbances requiring permanent pacemakers. This study aims to develop an AI-driven predictive recommendation system using Multidetector Computed Tomography (MDCT) data to optimize valve sizing and improve patient outcomes. Methods: Data were collected from 380 consecutive patients who underwent aortic valve replacement with a CPP prosthesis between 2011 and 2026. Two machine learning models were trained using preoperative MDCT features, including annular area, perimeter, and diameters. The first model predicted “normal” clinical labels, while the second used “penalized” labels adjusted for postoperative hemodynamic performance to discourage over-sizing. The dataset was split into training (80%) and testing (20%) subsets. Results: The mean patient age was 77.6 years. The model using normal labels achieved an overall accuracy of 91.84% (68.75% on the test set). The penalized label model showed improved performance with an overall accuracy of 92.89% (72.16% on the test set). MDCT provided highly reproducible objective metrics superior to echocardiography for calculating optimal sizing. Conclusions: The AI-driven recommendation system proves to be a reliable and reproducible tool for preoperative planning. By transitioning from subjective tactile assessment to predictive modeling, surgeons can better select valve sizes that minimize complications, particularly in minimally invasive approaches. Full article

Compared with the conventional push-broom imaging mode, conical scanning extends the imaging swath through rotational scanning and is suitable for high-resolution, wide-swath remote sensing. To achieve continuous full-coverage imaging, the camera must be mounted at a certain tilt angle and employ an off-axis optical system with a sufficiently large field of view (FOV). However, the tilted installation causes nonuniform irradiance and increased off-axis distortion, while wide-field off-axis imaging also introduces radiometric consistency problems in focal-plane multi-detector stitching. To address these issues, this study investigates the optical design of a tilted off-axis camera for conical-scan imaging. Under the constraints of full coverage and swath requirements, key optical parameters were jointly determined, and a lightweight wide-coverage off-axis three-mirror system was designed, optimized, and evaluated. The final system has a focal length of 1545 mm, an F-number of 8.4, and a full FOV of 23.4° × 11.7°. The modulation transfer function is greater than 0.41 at the Nyquist frequency, and the maximum distortion is less than 2.5446%. In addition, for the focal-plane optical stitching structure, the coupled effects of local structural vignetting and global geometric vignetting induced by the tilted installation were analyzed. The results show that the gray-level difference in the adjacent detector overlap regions is only 0.31–0.53 digital numbers (DN), and the full focal plane shows a smooth gray-level attenuation rate of 5.39–6.77%. These results indicate that vignetting has no significant effect on focal-plane stitching. The proposed camera is well suited for conical-scan imaging. Full article

To address the demand for wide-swath, high-resolution short-wave infrared (SWIR) imaging on resource-constrained spaceborne platforms, this study presents the design and on-orbit validation of a compact dual-channel push-broom (line-scanning) imaging system. The system adopts a transmissive optical architecture and a centralized, compact electronic control unit (ECU) configuration. By interleaving and mosaicking sixteen InGaAs linear array detectors, the system achieves an imaging swath of approximately 187 km and a nominal ground sampling distance of about 24 m, while maintaining a total instrument mass of 10.62 kg and a power consumption of approximately 12 W, thereby demonstrating a high level of integration and efficient resource utilization. To address focal plane consistency issues arising from multi-detector mosaicking, a closed-loop leveling method was developed using the modulation transfer function (MTF) as the primary performance metric. Through defocus estimation and quantitative correction of protrusions on a SiC substrate, convergence toward a unified confocal focal plane among multiple detectors was achieved. On-orbit image quality assessment indicates that the full width at half maximum (FWHM) of the line spread function (LSF) for both channels is approximately 1.38 pixels, with favorable signal-to-noise ratio (SNR) performance. These results validate the effectiveness of the proposed focal plane leveling strategy as well as the opto-mechanical-thermal design of the system. The proposed approach provides a practical pathway for the engineering implementation and consistency control of multi-detector mosaicked SWIR payloads under stringent resource constraints. Full article

Background and Objectives: Carotid artery stenosis has traditionally guided therapeutic decision-making; however, plaque morphology and composition are increasingly recognized as more reliable indicators of cerebrovascular risk than luminal narrowing alone. As imaging strategies shift toward vulnerability-based assessment, reproducibility of plaque characterization becomes essential for consistent clinical decision-making. This study aimed to evaluate interobserver agreement in carotid plaque assessment using multidetector computed tomography angiography (MDCTA) and to assess intermodality agreement with duplex ultrasonography (DUS). Materials and Methods: In this single-center study (January–September 2022), 50 patients with ≥60% internal carotid artery stenosis diagnosed by DUS (NASCET criteria), the majority of whom were asymptomatic (90%), were included. MDCTA examinations were independently analyzed by two radiologists, while DUS examinations were evaluated by a third observer. Plaque composition (lipid, fibrous, calcified), surface characteristics (regular, irregular, ulcerated), degree of stenosis, and plaque length were assessed. CT plaque characterization was based on Hounsfield unit (HU) thresholds (<50 HU lipid; 50–120 HU fibrous; >120 HU calcified). Interobserver agreement and intermodality agreement were calculated using Cohen’s kappa coefficient. Results: Good interobserver agreement was observed between the two MDCTA readers (κ = 0.751). Intermodality agreement between MDCTA and DUS was moderate (κ = 0.624 and κ = 0.595). Although significant differences were identified in 3 of 16 HU measurement points, no significant differences were found in overall plaque composition classification between MDCTA observers. DUS yielded significantly higher stenosis values (p = 0.007 and p = 0.005) and greater plaque length measurements (p < 0.0005) compared with MDCTA. Significant differences were also observed in plaque surface assessment between modalities (p = 0.044 and p = 0.033). Conclusions: MDCTA demonstrates good interobserver reproducibility for carotid plaque characterization, while intermodality agreement between MDCTA and DUS is moderate. Minor attenuation measurement differences do not significantly affect plaque classification; however, systematic intermodality differences in stenosis grading, plaque surface evaluation, and plaque length measurement should be considered in clinical decision-making. Full article

Background: This study aims to evaluate the prevalence, spectrum, and coexistence of anatomical variations in the major branches of the abdominal aorta using Multidetector Computed Tomography (MDCT) angiography, with a specific emphasis on analyzing sex-related differences in a large-scale cohort. Methods: A retrospective analysis was conducted on 1174 patients (63.8% male, 36.2% female; mean age 60.54) who underwent abdominal CT angiography between January 2023 and June 2024. Images were acquired using a 128-slice MDCT scanner and reconstructed for detailed vascular assessment. Statistical comparisons between genders were performed using Chi-square and Fisher–Freeman–Halton tests, with p < 0.05 considered significant. Results: The celiac trunk (93.3%), superior mesenteric artery (SMA) (97.1%), and inferior mesenteric artery (IMA) (98.5%) predominantly showed classical patterns. However, significant sex-related differences were identified. Females exhibited significantly higher rates of classical patterns for the celiac trunk (96.2% vs. 91.7%), IMA (99.1% vs. 98.1%), right hepatic artery (RHA) (91.5% vs. 82.6%), and left hepatic artery (LHA) (95.8% vs. 85.4%). Conversely, males showed a higher prevalence of complex variations, including replaced/accessory hepatic arteries and the absence of the common hepatic artery. The number of right and left renal arteries was similar between sexes and did not show a significant difference, while horseshoe kidney was detected only in males. Conclusions: Abdominal vascular structures adhere to classical anatomy more frequently in females, while males exhibit greater morphological variability. These findings emphasize the necessity of gender-specific preoperative vascular mapping to optimize surgical outcomes and reduce morbidity. Full article

Cone-beam computed tomography (CBCT) offers advantages of low radiation dose and rapid acquisition but suffers from scatter-induced shading artifacts that limit diagnostic value compared to multi-detector CT (MDCT). While CycleGAN enables unpaired image translation, its uniform loss application struggles with localized artifact removal. We propose a two-stage learning framework with YOLO-based region correction loss. Stage 1 trains a standard CycleGAN to establish stable CBCT-MDCT domain mapping. Stage 2 fine-tunes the model by applying gradient magnitude minimization loss selectively to artifact regions detected by a pretrained YOLO detector, enabling focused correction while preserving anatomical structures. Using 11,000 2D CBCT slices from 17 patients (14 training, 3 testing) and 23,500 2D MDCT slices from 50 patients, our method achieves a 14.0% reduction in artifact score compared to baseline CycleGAN while maintaining high structural similarity (SSIM > 0.96). Independent evaluation using integral nonuniformity (INU) and shading index (SI) confirms consistent improvement across physics-based metrics. The self-regulating mechanism, where YOLO detection confidence naturally decreases as artifacts diminish, provides automatic adjustment without manual intervention. This work demonstrates that combining staged learning with object detection offers an effective solution for localized artifact removal in medical image translation, potentially improving diagnostic accuracy while preserving the low-dose benefits of CBCT. Full article