Cross-sectional Imaging Research Articles

Rapid patient-specific organ dose estimation in computed tomography scans via integration of radiomics features and neural networks.

Computed tomography (CT) offers detailed cross-sectional images of internal anatomy for disease detection but carries a risk of solid cancer or blood malignancies due to exposure to X-ray radiation. This study aimed to develop a new method to quickly predict patient-specific organ doses from CT examinations by training neural networks (NNs) based on radiomics features. CT Digital Imaging and Communications in Medicine (DICOM) image data were exported to DeepViewer, a clinical autosegmentation software, to segment the regions of interest (ROIs) for patient organs. Radiomics feature extraction was performed based on the selected CT data and ROIs. Reference organ doses were computed using Monte Carlo (MC) simulations. Patient-specific organ doses were predicted by training a NN model based on radiomics features and reference doses. For the dose prediction performance, the relative root mean squared error (RRMSE), mean absolute percentage error (MAPE), and coefficient of determination (R2) were evaluated on the test sets. The robustness of the NN model was evaluated via the random rearrangement of patient samples in the training and test sets. The maximal difference between the reference and predicted doses was less than 1 mGy for all investigated organs. The range of MAPE was 1.68% to 5.2% for head organs, 11.42% to 15.2% for chest organs, and 5.0% to 8.0% for abdominal organs; the maximal R2 values were 0.93, 0.86, and 0.89 for the head, chest, and abdominal organs, respectively. The radiomics feature-based NN model can achieve accurate prediction of patient-specific organ doses at a high speed of less than 1 second using a single central processing unit, which supports its use as a user-friendly online clinical application.

Morphological analysis of the trigeminal nerve in trigeminal neuralgia using the nerve's centerline and multiple cross-sections of a 3D model.

Morphological changes such as angulation and torsion of the trigeminal nerve have been reported to cause trigeminal neuralgia (TN). The authors sought to quantify and objectively evaluate the morphological changes of the trigeminal nerve and to elucidate the cause of TN. The authors retrospectively analyzed the cases of patients with primary TN who had undergone microvascular decompression at a single facility between January 2016 and December 2022 and had both single-artery compression and a good postoperative outcome. The authors performed segmentation of the trigeminal nerve by using the patients' pre- and postoperative high-resolution MR images, and they then created a 3D model. The centerline of the trigeminal nerve was obtained using volume skeletonization, and the authors created multiple cross-sectional images by reslicing the 3D model perpendicular to the centerline. The parameters analyzed were as follows: the 1) centerline length; 2) centerline curvature; 3) centerline torsion; 4) cross-sectional area; 5) cross-sectional flattening ratio; and 6) cross-sectional long-axis angle. Comparisons were made for each parameter between the affected and unaffected side and between preoperative and postoperative trigeminal nerve findings. After exclusions, 70 of the 127 patients who underwent microvascular decompression during the study period were included in the analysis. In the preoperative images, the trigeminal nerve on the affected side had a significantly longer centerline length (p = 0.0003), greater curvature (p = 0.0012), smaller cross-sectional area (p < 0.0001), and greater flattening ratio (p = 0.0059) than the unaffected side. On the affected side, the preoperative trigeminal nerve had a significantly longer centerline length (p < 0.0001), greater curvature (p = 0.0028), and smaller cross-sectional area (p < 0.0001) compared to the postoperative trigeminal nerve. It is possible to analyze the morphological changes of the trigeminal nerve by using this method. In the preoperative trigeminal nerve on the affected side, the centerline is long and curved, and the cross-sectional area is small and flat. Further analyses may help clarify the pathophysiology, aid in diagnoses, and predict the efficacy of treatment.

A critical appraisal of the unmet needs for cross-sectional imaging techniques in Nigeria

A critical appraisal of the unmet needs for cross-sectional imaging techniques in Nigeria

Imaging of pancreatic serous cystadenoma and common imitators.

Pancreatic cystic neoplasms are lesions comprised of cystic components that show different biological behaviors, epidemiology, clinical manifestations, imaging features, and malignant potential and management. Benign cystic neoplasms include serous cystic neoplasms (SCAs). Other pancreatic cystic lesions have malignant potential, such as intraductal papillary mucinous neoplasms and mucinous cystic neoplasms. SCAs can be divided into microcystic (classic appearance), honeycomb, oligocystic/macrocystic, and solid patterns based on imaging appearance. They are usually solitary but may be multiple in von Hippel-Lindau disease, which may depict disseminated involvement. The variable appearances of SCAs can mimic other types of pancreatic cystic lesions, and cross-sectional imaging plays an important role in their differential diagnosis. Endoscopic ultrasonography has helped in improving diagnostic accuracy of pancreatic cystic lesions by guiding tissue sampling (biopsy) or cyst fluid analysis. Immunohistochemistry and newer techniques such as radiomics have shown improved performance for preoperatively discriminating SCAs and their mimickers.

Natural photosensitizer extraction from Delonix regia flowers for future photosensor for DSSCs applications

This study explores the utilization of Delonix regia (DR) (Gulmohar flower) as a natural photosensitizer in the fabrication of self-powered photosensors via dye-sensitized solar cells (DSSCs). Various photoanodes, including ZnO, ZnO/TiO2, and ZnO/TiO2/Nb2O5, were investigated for their performance enhancement in DR-based photosensors. The photoanodes were fabricated using different deposition methods sensitized with DR photosensitizer and characterized through X-ray diffraction analysis, Field emission scanning electron microscopy (FE-SEM), UV–visible, Fluorescence spectroscopy, and Fourier transform infrared spectroscopy (FTIR) analysis. The absorbance spectrum results indicate improved photosensitizer adsorption in visible light for the ZnO/TiO2/Nb2O5/DR photoanode compared to other configurations. The scanning electron microscopy (SEM) cross-section image of ZnO/TiO2/Nb2O5 confirmed the formation of a multilayer photoanode. Chronoamperometry experiments were conducted to evaluate the photo sensing behavior, focusing on sensitivity, photoresponsivity, specific detectivity, and quantum efficiency within the solar spectrum range. Among the devices, ZnO/TiO2/Nb2O5 exhibited the highest photoresponsivity (1.2 × 10 −3 A/W) and photodetectivity (26.78 × 104 Jones), demonstrating promising advancements in DR-sensitized photosensors. This research highlights the exceptional performance of DR-sensitized photoanodes, particularly ZnO/TiO2/Nb2O5, in advancing the capabilities of photo-sensing devices. The investigated configuration exhibited a rapid response speed of 723 ms and a remarkable sensitivity of 89.87% in detecting photo signals. These findings emphasize the potential of DR photosensitizers to enhance photo-sensing activities, with significant implications for diverse applications in photodetection. By leveraging the unique properties of DR, particularly its incorporation into ZnO/TiO2/Nb2O5, this study underscores the promising prospects for developing efficient self-powered photosensors. The insights gleaned from this work pave the way for further exploration and optimization in organic photosensors.

Optimization of 3D imaging time reduction by assessing spatial resolution in the slice selective direction using the ladder method

PurposeAssessing spatial resolution in MRI is challenging due to non-linearity. Despite the widespread use of 3D imaging in clinical practice for lesion detection and multi-planar reconstruction (MPR), the extended acquisition time poses a shortcoming. To address this, the “Slice resolution” parameter is utilized; however, its impact on MPR images is unclear. This study aims to assess spatial resolution using the ladder method, investigate the effects of diverse slice resolution settings in various imaging sequences, and propose optimal conditions. MethodsImages were acquired using various 3D imaging sequences—SPACE T1WI, SPACE T2WI, and VIBE T1WI—with different slice resolutions. Axial cross-section images were acquired and reconstructed into coronal cross-sections. The ladder method was employed for objective evaluation, including spatial frequency analysis. Additionally, visual evaluation was conducted and compared with ladder method results. ResultsFor three imaging sequences, the evaluated value of ladder method remained relatively constant from 100 % to 80 % slice resolution. However, the evaluated value decreased in low-spatial frequency for slice resolution below 70 %. ConclusionsResults from both ladder method and visual evaluations indicated image quality remained stable when the slice resolution was decreased to 80 %, potentially enabling a 20 % reduction in imaging time while preserving resolution in other cross-sections reconstructed by MPR.

Cleaning strategies for 3D-printed porous scaffolds used for bone regeneration fabricated via ceramic vat photopolymerization

Vat photopolymerization has gained prominence in bone tissue engineering owing to its capability to fabricate intricate structures that closely mimic the natural bone tissue. Thorough cleaning of uncured ceramic slurry from the as-printed structures is essential, as the presence of residue within the structure can obstruct pores during sintering. Given the limitations of conventional spray cleaning for these structures, this study seeks to investigate alternative cleaning approaches. Specifically, the efficacy of dibasic ester (DBE) and LithaSol 80, coupled with ultrasonic and soaking methods, is examined to identify optimal strategies for the thorough removal of viscous residual slurry (LithaBone HA 480). To examine the effect of temperature on cleaning ability, printed scaffolds were soaked in the cleaning solutions at 23, 30, 40, and 50 °C for 24 h. Based on the results, 50 °C was chosen as the temperature for further analysis while using both soaking (24, 48, 72 and 96 h) and ultrasonic (5, 15 and 30 min; 1, 2, 3, and 4 h) as the cleaning methods. The cross-sectional image of the scaffolds showed that at least 48 h and 30 min is required for effective cleaning with soaking and ultrasonic, respectively. Microstructure analysis of scaffolds cleaned with LithaSol 80 revealed smoother surfaces, while scaffolds treated with DBE showed visibly contracted pores with peeling effect suggesting that DBE exerts a more aggressive action on the cured slurry in contrast to LithaSol 80. Notably, significant difference in mass loss was observed between scaffolds treated with LithaSol 80 and DBE. The significantly higher mass loss observed with DBE suggests that it not only impacts uncured slurry but also possibly affects cured slurry. Accordingly, the results indicate that DBE is notably more effective in cleaning; however, LithaSol 80 is more appropriate for maintaining structural integrity combined with soaking cleaning method. No significant difference was observed in compressive strength between most sintered scaffolds.

Non-ketotic hyperglycemia-induced hemichorea-hemiballism – A case presentation and literature review

Non-ketotic hyperglycemia-induced hemichorea-hemiballism (NKHHH) is an infrequent hyperkinetic movement disorder, also known as diabetic striatopathy or Chorea hyperglycemia basal ganglia syndrome (C-H-BG), characterized by repetitive, uncontrollable movements in the unilateral or bilateral limbs. An insult to the contralateral basal ganglia causes NKHHH to develop. NKHHH is caused by ischemia, followed by non-ketotic hyperglycemia and poorly controlled diabetes. NKHHH is a rare condition with a unique cause that only affects one side of the corpus striatum (caudate nucleus and putamen). Clinical events of hemichorea-hemiballism, laboratory tests (elevated blood glucose and hemoglobin A1c levels), and imaging modalities (computed tomography and magnetic resonance imaging) all contribute to diagnosing NKHHH. The objective of this case report is to represent cross-sectional imaging findings in a 55-year-old female who presented with hemichorea-hemiballism following non-ketotic hyperglycemia. In conclusion, the clinical manifestation of NKHHH and its computed tomography (CT) and magnetic resonance imaging (MRI) findings are crucial in determining the appropriate management.

Multi-scale and multi-receptive field-based feature fusion for robust segmentation of plant disease and fruit using agricultural images

The accurate and fast assessment of plant diseases and fruits is important for sustainable and productive agriculture. However, typically manual methods are adopted for the assessment of plant diseases and fruit, which is a time-consuming, resource-intensive, and error-prone approach. A few artificial intelligence (AI)-based methods have been introduced to automate this process, but they show limitations in attaining high performance in challenging imaging conditions such as occlusions, poor lighting, noise, indistinctive boundaries, and excessive morphological variations. Moreover, current approaches also lack in providing computationally efficient solutions. To overcome these issues, two novel architectures are developed to segment plant diseases and fruits with higher segmentation performance and less computational requirements. The efficient feature fusion segmentation network (EFFS-Net) is the base network, and a multi-scale dilated feature fusion segmentation network (MDFS-Net) is the final network of this study. EFFS-Net uses an identity skip path-based feature fusion mechanism with an efficient grouped convolutional depth (EGCD) to provide satisfactory segmentation performance with high computational efficiency. MDFS-Net uses a multi-scale feature fusion mechanism and fuses low-level information in the EGCD and other sections of the network to learn detailed input features for delivering promising performance even in challenging imaging conditions. MDFS-Net also applies multiple receptive fields to the low-level information in the effective receptive field processing (ERFP) block for fusion near the pixel classification stage for further performance enhancement.Both networks are evaluated using a Brazilian Arabica coffee leaf (BRACOL) image dataset, an Australian Center for Field Robotics orchard fruit (apple) dataset, and a necrotized cassava root cross-section image dataset. The proposed method provides a promising segmentation performance, achieving dice similarity coefficients of 88.81 %, 95.01 %, and 86.04 % with performance improvement of 3.5 %, 2.6 %, and 1.07 % on the three datasets, respectively, with approximately ten times less number of required trainable parameters compared with the state-of-the-art methods.

Estimated Disease Progression Trajectory of White Matter Disruption in Unilateral Temporal Lobe Epilepsy: A Data-Driven Machine Learning Approach.

Although the involvement of progressive brain alterations in epilepsy was recently suggested, individual patients' trajectories of white matter (WM) disruption are not known. We investigated the disease progression patterns of WM damage and its associations with clinical metrics. We examined the cross-sectional diffusion tensor imaging (DTI) data of 155 patients with unilateral temporal lobe epilepsy (TLE) and 270 age/gender-matched healthy controls, and we then calculated the average fractional anisotropy (FA) values within 20 WM tracts of the whole brain. We used the Subtype and Stage Inference (SuStaIn) program to detect the progression trajectory of FA changes and investigated its association with clinical parameters including onset age, disease duration, drug-responsiveness, and the number of anti-seizure medications (ASMs). The SuStaIn algorithm identified a single subtype model in which the initial damage occurs in the ipsilateral uncinate fasciculus (UF), followed by damage in the forceps, superior longitudinal fasciculus (SLF), and anterior thalamic radiation (ATR). This pattern was replicated when analyzing TLE with hippocampal sclerosis (n = 50) and TLE with no lesions (n = 105) separately. Further-progressed stages were associated with longer disease duration (p < 0.001) and a greater number of ASMs (p = 0.001). the disease progression model based on WM tracts may be useful as a novel individual-level biomarker.

Comparative Analysis of Impacted Mandibular Third Molar Root Proximity to the Mandibular Canal using Orthopantomography and Cone-beam Computed Tomography Imaging Modalities: A Pilot Study

Abstract Introduction: Fully detect risks of nerve damage, which can lead to temporary or permanent issues. Cone-beam computed tomography (CBCT) offers a three-dimensional (3D) view, providing more detailed visualisation of anatomical structures and their spatial relationships, which improves the accuracy of predicting nerve exposure. The study aims to evaluate and compare these imaging techniques’ effectiveness in categorising the relationship between third molars and the inferior alveolar canal, emphasising the importance of precise imaging for safer surgical outcomes. Materials and Methods: A pilot study involving 20 patients, representing 10% of the total sample size of 200, was conducted at Ahmedabad Dental College’s Department of Oral Medicine and Radiology. Investigators, trained to interpret radiological images from orthopantomography (OPG) and CBCT, compared their interpretations with those of two experts. A high inter-rater reliability was confirmed with a kappa statistic of 0.98. Following ethical approval, data were retrospectively collected from 20 cases, with digital OPG and CBCT images analysed and classified according to established criteria. Results: The results revealed a significant association between the results diagnosed through OPG and CBCT indicating similarity in their diagnosis. It was also seen that there was no bias towards the gender and the distribution was similar in case of diagnosis through OPG or CBCT. Conclusion: CBCT demands an in-depth understanding of anatomy and pathology, coupled with proficiency in operating imaging software and the ability to identify abnormalities in cross-sectional images. When executed and interpreted accurately, CBCT proves to be an exceptionally valuable tool in clinical dental practice. Its detailed 3D imaging capabilities enhance the assessment of complex cases, such as those involving intricate anatomical structures and pathologies. By providing comprehensive views that surpass traditional two-dimensional imaging, CBCT aids in precise diagnosis and treatment planning, making it an indispensable resource for addressing various dental conditions effectively.

Oxygen Vacancy Compensation-Induced Analog Resistive Switching in the SrFeO3-δ/Nb:SrTiO3 Epitaxial Heterojunction for Noise-Tolerant High-Precision Image Recognition.

Neuromorphic computing, inspired by the brain's architecture, promises to surpass the limitations of von Neumann computing. In this paradigm, synaptic devices play a crucial role, with resistive switching memory (memristors) emerging as promising candidates due to their low power consumption and scalability advantages. This study focuses on the development of metal/oxide-semiconductor heterojunctions, which offer several technological advantages and have broad potential for applications in artificial neural synapses. However, constructing high-quality epitaxial interfaces between metal and oxide semiconductors and designing modifiable contact barriers are challenging. Herein, we construct high-quality epitaxial metal/semiconductor interfaces based on the metallicity of the perovskite phase SrFeO3-δ (PV-SFO) and a small Schottky barrier in contact with Nb-doped SrTiO3 (NSTO). X-ray diffraction patterns, reciprocal space mapping results, and cross-sectional transmission electron microscopy images reveal that the prepared PV-SFO film exhibits a perfect single-crystal structure and an excellent epitaxial interface with the NSTO (111) substrate. The corresponding memristor exhibits analog-type resistive-variable characteristics with an ON/OFF ratio of ∼1000, stable data retention after 10,000 s, and no noticeable fluctuation in resistance after 10,000 pulse cycles. Electron energy loss spectroscopy, first-principles calculations, and electrical measurements reveal that compensating or restoring oxygen vacancies at the NSTO surface decreases or increases the contact barrier between PV-SFO and NSTO, respectively, thereby gradually regulating the resistance value. Furthermore, high-quality epitaxial PV-SFO/NSTO devices achieve up to 98.21% recognition accuracy for handwriting recognition tasks using LeNet-5-based network structures and 92.21% accuracy for color images using visual geometry group (VGG) network structures. This work contributes to the advancement of interface-type memristors and provides valuable insights into enhancing synaptic functionality in neuromorphic computing systems.

In-Situ X-ray Diffraction/Fluorescence Analysis of Dy–Cu Electrochemical Alloying and Dealloying in Molten LiCl–KCl–DyCl3

Recycling spent Nd magnets is essential for maintaining a stable supply of rare earth (RE) elements prompting the development of a one-step recycling process using molten salt and alloy diaphragms. In this study, to investigate the mechanism of rapid alloy formation, an in-situ X-ray diffraction/fluorescence analysis of Dy–Cu electrochemical alloying and dealloying in molten LiCl–KCl–DyCl3 was performed. During the electrolysis, a diffraction peak corresponding to Cu was observed. In addition, X-ray fluorescence peaks of Dy were observed throughout the process. The area of the Dy X-ray fluorescence peak increased as the alloying progressed but remained relatively constant during the dealloying process. Compared with Dy–Ni alloying/dealloying, the areas of the fluorescence peaks were smaller. The results suggest a slower alloy formation rate with Cu than with Ni. Cross-sectional images show that the alloy formation rate is lower for Cu, which can be attributed to a larger crystal mismatch between the substrate and alloyed layer.

Assessment of the Trabecular Bone Microstructure Surrounding Impacted Maxillary Canines Using Fractal Analysis on Cone-Beam Computed Tomography Images.

To assess the impact of the presence or position (buccal/palatal) of impacted canines on trabecular bone density using fractal analysis (FA) on cone-beam computed tomography (CBCT) images, and to compare the results with a control group without impacted canines. This retrospective study included 41 patients with unilateral impacted canines (30 palatal, 11 buccal) and a control group of 39 patients who underwent surgically assisted rapid maxillary expansion. All patients had CBCT images recorded for diagnostic and treatment purposes. Cross-sectional CBCT images were obtained between the first and second premolars on both sides of the patients' maxilla. From these images, fractal dimension (FD) was measured in a 20 × 20 pixel region of interest in the trabecular bone using the ImageJ software. The FD values were significantly higher on the impacted side in the impacted canine group (p = 0.02). Within the impacted canine group, a significant increase in FD was observed on the impacted side in the buccal-impacted subgroup (p = 0.02), while no significant difference was observed in the palatal-impacted subgroup (p > 0.05). According to the results of our study, there is an association between the position of the impacted canine and trabecular bone density. An increased trabecular bone density may play a role in the etiology of buccally impacted canines. Clinicians should consider anchorage planning, and appropriate force level, during the forced eruption of buccally impacted canines with high surrounding bone density, to minimize undesirable movements and achieve optimal treatment outcomes.

Experimental study on tribological behavior of a binderless cemented carbide at high contact stress

Knowledge of frictional evolution and associated damage mechanism during sliding wear conditions using binderless WC-based cemented carbide is lacking. In this study, the frictional evolution and corresponding transformation of microstructure, and wear mechanisms of Al2O3/WC-based cemented carbide due to the effect of different contact pressure, especially high pressure have been explored using a reciprocating ball-on-flat sliding wear tester, which was experimentally simulated following the ASTM G133–02 standard. The dynamic curves in friction coefficient with the sliding time were described. The microscopic 3D topography of contact surface was obtained by the MFP-3D atomic force microscope. The material removal and the wear rate were discussed. Worn surface morphologies at different moments, cross-sectional images of wear tracks at different loads, and wear debris were taken by field emission scanning electron microscope. The results suggested that the pressure plays a decisive role in frictional evolution and wear characteristics. Two models of frictional evolution were declared. A novel “surge” phenomena in friction coefficient was found and explained at high contact pressure. Wear transition from mild wear to severe wear was confirmed. More than one wear mechanism was observed, including micro-cutting (polishing), generation and propagation of cracks, cracking-induced spalling, plastic deformation, and the formation of tribolayer.

Back to basics: lung volumes on pediatric chest X-rays-pitfalls and diagnostic implications.

Evaluating lung "volumes" when interpreting pediatric chest radiographs is useful for supporting the diagnosis of lung pathology in children. Lung volumes can be estimated using semi-objective criteria such as anterior rib counting. Estimating lung volumes is one advantage plain radiographs have over other imaging modalities such as ultrasound or even cross-sectional imaging (Computed Tomography and Magnetic Resonance Imaging, where volumes can be calculated, but remain difficult to quickly be appreciated subjectively or semi-objectively in clinical practice). Lung hyperinflation is often a surrogate of air-trapping and may be suggestive of diseases such as bronchiolitis. Identifying under-inspired chest radiographs is also important to avoid misinterpreting findings related to low lung volumes as pathology, which is a significant diagnostic pitfall in children. This pictorial review will demonstrate the method for evaluating lung volumes, specifically for identifying lung hyperinflation as a surrogate of air-trapping and under-inspiration for avoiding false positive diagnoses.

Study on microwave ablation temperature prediction model based on grayscale ultrasound texture and machine learning.

Temperature prediction is crucial in the clinical ablation treatment of liver cancer, as it can be used to estimate the coagulation zone of microwave ablation. Experiments were conducted on 83 fresh ex vivo porcine liver tissues at two ablation powers of 15 W and 20 W. Ultrasound grayscale images and temperature data from multiple sampling points were collected. The machine learning method of random forests was used to train the selected texture features, obtaining temperature prediction models for sampling points and the entire ultrasound imaging area. The accuracy of the algorithm was assessed by measuring the area of the hyperechoic area in the porcine liver tissue cross-section and ultrasound grayscale images. The model exhibited a high degree of accuracy in temperature prediction and the identification of coagulation zone. Within the test sets for the 15 W and 20 W power groups, the average absolute error for temperature prediction was 1.14°C and 4.73°C, respectively. Notably, the model's accuracy in measuring the area of coagulation was higher than that of traditional ultrasonic grey-scale imaging, with error ratios of 0.402 and 0.182 for the respective power groups. Additionally, the model can filter out texture features with a high correlation to temperature, providing a certain degree of interpretability. The temperature prediction model proposed in this study can be applied to temperature monitoring and coagulation zone range assessment in microwave ablation.

Role of Optical Coherence Tomography in Vasculitis-Associated Pulmonary Hypertension and Chronic Thromboembolic Pulmonary Hypertension.

Identifying and understanding the microstructural changes within the wall of the pulmonary artery (PA) is crucial for elucidating disease mechanisms and guiding treatment strategies. We assessed the utility of optical coherence tomography (OCT) in identifying such changes within segmental/subsegmental PAs and compared the morphological variations in WHO group 4 pulmonary hypertension associated with Behcet Disease (BD), Takayasu arteritis (TA) and chronic thromboembolic pulmonary hypertension (CTEPH). Idiopathic pulmonary arterial hypertension (IPAH) patients served as controls.Methods and Results: A total of 197 cross-sectional images were analyzed from 20 consecutive patients. BD patients exhibited lower %wall area and mean wall thickness (MWT) compared with CTEPH, TA and, IPAH patients. TA patients showed a notably higher %wall area, which was significant in IPAH and BD patients. Variations in %wall area measurements were observed across distinct cross-sectional segments of the PA within individual patients (22% in CTEPH, 19% in BD, 16% in TA, 23% in IPAH patients). Intravascular webs, bands, and thrombi were observed in BD and CTEPH patients. OCT provided clear delineation of vascular wall calcifications and adventitial vasa vasorum. No procedure-related complications were observed. PA involvement differs among the various etiologies of PH, with the PA being heterogeneously affected. OCT offers promise in elucidating microstructural vascular wall changes and providing insights into disease mechanisms and treatment effects.

Characteristics of Open-Graded Friction Course Macrotexture and Macrostructure and Its Effect on Skid Resistance under Rainfall.

An Open-Graded Friction Course (OGFC) presents a rough surface and a porous structure and provides skid resistance under wet conditions, differing from that of a dense graded mixture. This study explored the distribution of surface macrotexture with depth in OGFC. Using cross-sectional images and semantic image segmentation techniques, the internal structure, porosity, and void size distribution were analyzed to assess the effectiveness of rainfall drainage. Skid resistance was evaluated with a British Pendulum Tester, focusing on the influence of surface macrotexture and internal macrostructure, particularly with regard to contact depth. Results show that finer gradations increase surface roughness peaks, which are concentrated near the top surface. In contrast, coarser mixtures exhibit a greater effective contact depth and more peaks with higher curvature. Finer gradations also result in lower porosity, greater void dispersion, and smaller average void diameters. During heavy rainfall, OGFC-13 exhibits the highest friction coefficient due to its effective contact, surface roughness, and internal voids, which facilitate water expulsion. This research provides insights into the skid resistance mechanism of OGFC in wet conditions and offers practical guidance for selecting the optimal gradation.

Welding electrical connections between battery sheet metal materials and additively manufactured (AM) aluminum components: The effect of surface roughness

The integration of additive manufacturing's design versatility with a push for electrification can lead to unique innovations. In this context, when discussing welded joints, their quality and reliability play a significant role. The restricting factor for the use of laser powder bed fusion of metal (PBF-LB/M) additive manufactured (AM) parts is often their surface quality in the as-built state. In addition, the surface quality changes when part plane orientation changes. In this study, AlSi10Mg aluminum test samples were additive manufactured in seven different build angles. The AM samples were glass bead blasted after manufacturing, and the surface roughness of the joint surface area was optically measured. After the measurement, the AM samples were welded to nickel-plated copper and aluminum sheet metals. A continuous wave single-mode fiber laser with scanner optics was used to carry out the welding experiments in lap joint configuration. The structural and mechanical properties of the welds were evaluated by the macroscopic images of weld cross sections and tensile testing of the samples. The electric resistivity of the samples was also tested. Based on the measurement results of the samples, the impact of surface quality was discussed. The results indicated that there was no clear effect of building angle on the final weld quality. The worst surface quality in the joint area was on the test pieces in which the joint surface was facing down toward the build plate.