Dual Scanning Research Articles

Terahertz single/dual beam scanning with tunable field of view by cascaded metasurfaces

Dynamic beam scanning with a dynamically tunable beam number, beam direction, and beam polarization remains a challenge in the terahertz gap, which is urgently needed for terahertz radar, next-generation wireless communication, and imaging applications. Different from programmable metasurfaces with element-level phase control, the beam direction is dynamically controlled by two cascaded all-dielectric metasurfaces during in-plane rotation. For a pair of circularly polarized beams with opposite handedness, the scanning field of view (FOV) can be the same or different according to the independent phase modulation in both layers and for both polarization states. Switchable single-beam and dual-beam scanning is achieved by controlling the incident polarization, which covers the ±60° FOV at 0.291 THz with an angular step of 1° and an average gain of 16.2 dBi. The output beam is quasi-circular polarized with an average ellipticity of 0.83. Single beam scanning along a Fibonacci spiral trajectory and dual beam scanning along symmetric and asymmetric trajectories are experimentally validated. Different beam scanning processes are recorded using a terahertz camera, which show good agreement with the theoretical prediction. The wide field-of-view continuous beam scanning with a switchable number of beams and a flexible FOV may have a significant impact on the development of terahertz radar and terahertz intelligent antennas.

Patient radiation risk reduction by controlling the tube start angle in single and dual source spiral CT scans: A simulation study.

Organ doses in spiral CT scans depend on the tube startangle. To determine the effective dose in single source CT (SSCT) and dual source CT (DSCT) scans as a function of tube start angle and spiral pitch value to identify the dose reduction potential by selecting the optimal startangle. Using Monte Carlo simulations, dose values for different tube positions with an angular increment of and a longitudinal increment of were simulated over a range of with collimations of , , and . The simulations were performed for the thorax region of six adult patients based on clinical CT data. From the resulting dose distributions, organ doses and effective dose were determined as a function of tube angle and longitudinal position. Using these per-view dose data, the individual organ doses, as well as the total effective dose, were determined for spiral scans with and without tube current modulation (TCM) with pitch values ranging from 0.5 to 1.5 for SSCT and up to 3.0 for DSCT. The dose of the best and worst tube start angle in terms of dose was determined and compared to the mean dose over all tube startangles. With increasing pitch and collimation, the dose variations from the effective dose averaged over all start angles increase. While for a collimation of , the variations from the mean dose value stay below for SSCT, we find that for a spiral scan with a pitch of 3.0 for DSCT with TCM and collimation of , the dose for the best starting angle is on average lower than the mean value and lower than the maximumvalue. Variation of the tube start angle in spiral scans exhibits substantial differences in radiation dose especially for high pitch values and for high collimations. Therefore, we suggest to control the tube start angle to minimize patientrisk.

Application research on asthma-COPD overlap using low-dose CT scan and quantitative analysis

The aim of this study was to assess the proximal airway remodeling, emphysema, and air trapping of asthma-COPD Overlap. 20 ACO patients, 55 mild to moderate COPD patients and 38 non-severe asthma patients were participated in low-dose dual phase CT scanning and pulmonary function test, comparative analysis was performed to identify differences in CT measurements among three groups. (Ⅰ) The average age and smoking index of ACO and mild to moderate COPD were both higher than non-severe asthma. ACO and mild to moderate COPD group had a higher proportion of males than non-severe asthma. (Ⅱ) In terms of pulmonary function test, FEV1 (%Pred), FEV1/FVC%, MEF25% (%Pred), MEF 50% (%Pred), MMEF (%Pred), and PEF (%Pred) in ACO were significantly reduced than those in non-severe asthma. (Ⅲ) On proximal airway parameters, ACO exhibited higher WA% and Pi10 compared to mild to moderate COPD. However, there was no statistically significant difference in WA% and Pi10 between ACO and non-severe asthma. (Ⅳ) On CT lung function, the emphysema index VI-910ex of ACO was significantly higher than non-severe asthma.Additionally, ACO demonstrated higher MLDex and VI-856ex compared to non-severe asthma. Compared with non-severe asthma, ACO is more common in male patients with older age and a longer history of smoking, which had more severe airflow obstruction and airway dysfunction than non-severe asthma.ACO showed more obvious proximal airway remodeling than mild to moderate COPD, and was more similar to non-severe asthma.The extent of emphysema and air trapping in ACO were more pronounced compared to non-severe asthma.

Spoof surface plasmon Polaritons dual beam scanning antenna for 5G application

Dual beam scanning (DBS) antenna exited by two different spoof surface plasmon polaritons (SSPPs) transmission lines is proposed in this paper. The antenna is constructed by placing three rows of circular patches on both sides of two different planar SSPPs waveguide. These patches convert the SSPP guided waves into radiating waves. This simple single-layer antenna is characterized by dual without need to use switches or other complex configurations. It is designed to support application of several 5G sub-6 GHz bands (3.5 (n78) GHz, 3.7 (n77) GHz, and 4.5 (n79) GHz). The proposed antenna realizes the dual beam scanning by controlling the dispersion properties and field confinement along two different SSPPs transmission lines, based on different propagation constant. Numerical simulations are carried out by CST Microwave Studio and Ansys HFSS. These numerical simulations are verified by experimental results over the operating frequency band from 1 GHz to 6 GHz.

Computer-Assisted Implant Planning: A Review of Data Registration Techniques.

Computer-assisted implant planning allows for a comprehensive treatment plan by combining radiographic data provided by a Cone Beam Computed Tomography (CBCT) with surface optical scan (IOs) data that includes patient intraoral situation and the intended restorative planning. Integrating a tailored restorative design with the patient's anatomical conditions through virtual implant planning allows for an ideal bio-restorative treatment planning to maximize biological, functional, and esthetic outcomes. This article discusses dataset registration techniques that combine radiographic CBCT data with restorative information as the main path to create a virtual patient. The described techniques include the use of removable radiographic templates with radiopaque markers, dual scan technique, and direct digital file registration of intra-oral scans using anatomical references. Depending on the individual clinical situation, different factors must be considered to appropriately select methods that achieve an optimal registration of diverse datasets. An inherent challenge lies in the presence of scattering artifacts in CBCT scans. Two approaches are proposed for these situations - the use of chairside-fabricated composite resin markers or adhesive spot-markers fabricated for the use with CBCT scans. Both techniques exhibit limitations that need to be taken into consideration. Further approaches should be developed for situations involving scattering in CBCT.

Sensitive Multiplexed MicroRNA Spatial Profiling and Data Classification Framework Applied to Murine Breast Tumors.

MicroRNAs (miRNAs) are small RNAs that are often dysregulated in many diseases, including cancers. They are highly tissue-specific and stable, thus, making them particularly useful as biomarkers. As the spatial transcriptomics field advances, protocols that enable highly sensitive and spatially resolved detection become necessary to maximize the information gained from samples. This is especially true of miRNAs where the location their expression within tissue can provide prognostic value with regard to patient outcome. Equally as important as detection are ways to assess and visualize the miRNA's spatial information in order to leverage the power of spatial transcriptomics over that of traditional nonspatial bulk assays. We present a highly sensitive methodology that simultaneously quantitates and spatially detects seven miRNAs in situ on formalin-fixed paraffin-embedded tissue sections. This method utilizes rolling circle amplification (RCA) in conjunction with a dual scanning approach in nanoliter well arrays with embedded hydrogel posts. The hydrogel posts are functionalized with DNA probes that enable the detection of miRNAs across a large dynamic range (4 orders of magnitude) and a limit of detection of 0.17 zeptomoles (1.7 × 10-4 attomoles). We applied our methodology coupled with a data analysis pipeline to K14-Cre Brca1f/fTp53f/f murine breast tumors to showcase the information gained from this approach.

Innovative Method For Simplifying Dual Scan Technique

Innovative Method For Simplifying Dual Scan Technique

Miniaturized confocal Raman and Laser-induced breakdown spectroscopy imaging system based on micro-electro-mechanical mirror

Detection of the elemental and molecular structural distribution with high resolution and miniaturization of unknown minerals is a main bottleneck in deep space exploration and geology analysis. The aim is to enhance the accuracy of the chemical analysis of micro-samples by combining the distribution information from Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS). The existing Raman-LIBS imaging methods are difficult to balance the imaging performance and system volume. There is an urgent need to develop a Raman-LIBS imaging method with miniaturization, and high imaging performance. A miniaturized Raman-LIBS imaging instrument based on the micro-electro-mechanical (MEMS) mirror has been developed to overcome these challenges. The instrument utilizes dual 2D MEMS mirror scanning technology to shorten the optical length of the system and improve the detection efficiency of hybrid spectral signals. The optical probe measures 94 mm × 66 mm, and has an axial focusing ability of approximately 40 nm, with a lateral resolution of approximately 700 nm for Raman maps and 9.5 μm for LIBS maps. As a proof experiment, 3D high-resolution Raman-LIBS hybrid spectral distribution maps of meteorite Tisserlitine 001 were obtained. The attainment of high imaging performance and miniaturization in hybrid spectral imaging is crucial for on-site chemical analysis. The proposed instrument enables in-situ spectrum and multispectral imaging with miniaturization, high spatial resolution, and high stability. The instrument is a powerful tool for composition and structural information characterization in the fields of space exploration and geological exploration.

Construction of a cryogenic dual scanner magnetic force microscope equipped with piezoresistive cantilever

We present a low-temperature magnetic force microscope (MFM) incorporating a piezoresistive cantilever and a dual-range scanner for experiments across a wide temperature range from cryogenic levels to room temperature. The piezoresistor-based MFM eliminates the need for optical readjustment, typically required due to thermal expansion at varying temperatures, thereby providing a more stable and precise measurement environment. The integration of a dual scanner system expands the versatility of scanning operations, enabling accurate sample positioning for detailed exploration of magnetic and superconducting properties under diverse thermal conditions. To demonstrate the capabilities of our MFM, we show detailed imaging of Fe3GaTe2, a van der Waals ferromagnet, and Yb0.7Y0.3CuAs2, a ferromagnetic cluster glass material. These studies demonstrate the potential of our MFM in revealing intricate details of magnetic domain dynamics and contribute to our understanding of materials exhibiting the anomalous Hall effect as well as superconducting phenomena.

The Application of 68Ga-Somatostatin Analog and 18F-FDG PET/CT for Bone Metastasis from Neuroendocrine Tumors

Introduction: Aims of the study were to assess the differences in the diagnostic efficacy of 68Ga-somatostatin receptor analogs (68Ga-SSAs) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) for detecting bone metastases in neuroendocrine neoplasm (NEN) and to analyze the correlation between imaging features and clinical features of BMs. Methods: We retrospectively analyzed the clinical and imaging data of 213 NEN patients who underwent 68Ga-SSA PET/CT and were finally diagnosed as BMs by pathology or follow-up. Of those, 103 patients underwent 18F-FDG PET/CT within 7 days after 68Ga-SSA PET/CT. Result: The BM detection rate of 68Ga-SSA PET/CT was higher than 18F-FDG PET/CT (86.4% vs. 66.0%, p = 0.02) in 103 patients with dual scanning. Meanwhile, the number of positive lesions in 68Ga-SSA PET/CT was significantly more than in 18F-FDG PET/CT (3.37 ± 1.95 vs. 2.23 ± 2.16, t = 4.137, p < 0.001). Most bone metastasis lesions presented as osteogenic change in CT (55.4%, 118/213). Concerning the primary tumor, the most frequent were of pancreatic origin (26.3%, 56/213), followed by rectal origin (22.5%, 48/213), thymic origin in 33 cases (15.5%), pulmonary origin in 29 cases (13.6%), paraganglioma in 20 cases (9.4%). The efficiency of 68Ga-SSA PET/CT to detect BMs was significantly correlated with the primary site (p = 0.02), with thymic carcinoid BMs being the most difficult to detect, and the positive rate was only 60.6% (20/33). However, 18F-FDG PET/CT positive rate was 76.92% (10/13) in thymic carcinoid BMs. In addition, the BMs of 7 patients in this study were detected by 68Ga-SSA PET earlier than CT for 4.57 months (range: 2–10 months). Conclusion: 68Ga-SSA PET/CT has higher sensitivity for detecting the BMs of NEN than 18F-FDG and detects the BM earlier than CT. Moreover, 18F-FDG PET/CT should be a complement for diagnosing the BMs of thymic carcinoids.

Prevalence of osteoporosis &amp; osteopenia in transfusion-dependent thalassemia in Sulaimaniyah city, Iraq

Background and objectives: Although blood transfusion and iron chelation increase the lifespan of thalassemic patients, these patients face many complications, including osteoporosis and osteopenia. Thus, we aimed to determine prevalence rates of osteoporosis/osteopenia using Dual Energy X-Ray Absorptiometry in transfusion-dependent thalassemia patients and its relationship with chelation agents and body mass index. Methods: This retrospective study included 150 patients with transfusion-dependent thalassemia in the Thalassemia and Congenital Blood Disorders Center, Sulaimaniyah, Iraq, from December 2021 to July 2022. The participant’s information was collected from the hospital database, including sociodemographic characteristics, bone mineral density status, and the number of items used for chelation. A Dual Energy X-Ray Absorptiometry bone scan was used to check the bone mineral density. Results: The mean age of patients was 19.59±7.59, body mass index was 21.23±18.13, and most (53.3%) were females. Dual Energy X-Ray Absorptiometry results showed that 53.3% of the patients had osteopenia, 21.3% had osteoporosis, 36.7% had average bone mineral density, and 6.7% had low bone mineral density for age. In addition, there was a significant difference between the frequencies of bone density disorders in patients who used one chelating agent (46.4%) versus two chelating agents (85%) (P?0.001). Also, there was a significant difference between the incidence of bone density disorders with low and average body mass index (78%) in comparison with overweight and obese patients (8%) (P?0.001). Conclusions: There is a high prevalence of osteoporosis and osteopenia in transfusion-dependent thalassemia patients, which are more prone to trauma and bone fracture.

Facilitating Atom Probe Tomography of 2D MXene Films by In Situ Sputtering.

2D materials are emerging as promising nanomaterials for applications in energy storage and catalysis. In the wet chemical synthesis of MXenes, these 2D transition metal carbides and nitrides are terminated with a variety of functional groups, and cations such as Li+ are often used to intercalate into the structure to obtain exfoliated nanosheets. Given the various elements involved in their synthesis, it is crucial to determine the detailed chemical composition of the final product, in order to better assess and understand the relationships between composition and properties of these materials. To facilitate atom probe tomography analysis of these materials, a revised specimen preparation method is presented in this study. A colloidal Ti3C2Tz MXene solution was processed into an additive-free free-standing film and specimens were prepared using a dual beam scanning electron microscope/focused ion beam. To mechanically stabilize the fragile specimens, they were coated using an in situ sputtering technique. As various 2D material inks can be processed into such free-standing films, the presented approach is pivotal for enabling atom probe analysis of other 2D materials.

The 3D-printed shell complete denture technique: Simplifying prosthodontic diagnosis prior to implant planning.

Traditionally, artificial teeth arrangements or the definitive complete dentures are used to establish important prosthodontic parameters such as the occlusal plane orientation, vertical dimension, and the incisal edge position. The relationship of these elements with the underlying bony structures is commonly evaluated using advanced planning protocols such as the dual scan technique. This technique article presents an uncomplicated alternative approach to establish these parameters intraorally using a 3D-printed shell complete denture generated from a 3D scan of the patient's existing complete denture.

Active Dual Line-Laser Scanning for Depth Imaging of Piled Agricultural Commodities for Itemized Processing Lines.

The accurate depth imaging of piled products provides essential perception for the automated selection of individual objects that require itemized food processing, such as fish, crabs, or fruit. Traditional depth imaging techniques, such as Time-of-Flight and stereoscopy, lack the necessary depth resolution for imaging small items, such as food commodities. Although structured light methods such as laser triangulation have high depth resolution, they depend on conveyor motion for depth scanning. This manuscript introduces an active dual line-laser scanning system for depth imaging static piled items, such as a pile of crabs on a table, eliminating the need for conveyor motion to generate high-resolution 3D images. This advancement benefits robotic perception for loading individual items from a pile for itemized food processing. Leveraging a unique geometrical configuration and laser redundancy, the dual-laser strategy overcomes occlusions while reconstructing a large field of view (FOV) from a long working distance. We achieved a depth reconstruction MSE of 0.3 mm and an STD of 0.5 mm on a symmetrical pyramid stage. The proposed system demonstrates that laser scanners can produce depth maps of complex items, such as piled Chesapeake Blue Crab and White Button mushrooms. This technology enables 3D perception for automated processing lines and offers broad applicability for quality inspection, sorting, and handling of piled products.

A dual-energy CT reconstruction method based on anchor network from dual quarter scans.

Compared with conventional single-energy computed tomography (CT), dual-energy CT (DECT) provides better material differentiation but most DECT imaging systems require dual full-angle projection data at different X-ray spectra. Relaxing the requirement of data acquisition is an attractive research to promote the applications of DECT in wide range areas and reduce the radiation dose as low as reasonably achievable. In this work, we design a novel DECT imaging scheme with dual quarter scans and propose an efficient method to reconstruct the desired DECT images from the dual limited-angle projection data. We first study the characteristics of limited-angle artifacts under dual quarter scans scheme, and find that the negative and positive artifacts of DECT images are complementarily distributed in image domain because the corresponding X-rays of high- and low-energy scans are symmetric. Inspired by this finding, a fusion CT image is generated by integrating the limited-angle DECT images of dual quarter scans. This strategy enhances the true image information and suppresses the limited-angle artifacts, thereby restoring the image edges and inner structures. Utilizing the capability of neural network in the modeling of nonlinear problem, a novel Anchor network with single-entry double-out architecture is designed in this work to yield the desired DECT images from the generated fusion CT image. Experimental results on the simulated and real data verify the effectiveness of the proposed method. This work enables DECT on imaging configurations with half-scan and largely reduces scanning angles and radiation doses.

Evaluating Prognosis of Gastrointestinal Metastatic Neuroendocrine Tumors: Constructing a Novel Prognostic Nomogram Based on NETPET Score and Metabolic Parameters from PET/CT Imaging.

The goal of this study is to compare the prognostic performance of NETPET scores, based on gallium-68 DOTANOC (68Ga-DOTANOC) and fluorine-18 fluorodeoxyglucose (18F-FDG) Positron Emission Tomography-Computed Tomography (PET-CT), and PET-CT metabolic parameters in metastatic gastrointestinal neuroendocrine tumors (GI-NET), while constructing and validating a nomogram derived from dual-scan PET-CT. In this retrospective study, G1-G3 GI-NET patients who underwent 68Ga-DOTANOC and 18F-FDG PET scans were enrolled and divided into training and internal validation cohorts. Three grading systems were constructed based on NETPET scores and standardized uptake value maximum (SUVmax). LASSO regression selected variables for a multivariable Cox model, and nomograms predicting progression-free survival (PFS) and overall survival (OS) were created. The prognostic performance of these systems was assessed using time-dependent receiver-operating characteristic (ROC) curves, concordance index (C-index), and other methods. Nomogram evaluation involved calibration curves, decision curve analysis (DCA), and the aforementioned methods in both cohorts. In this study, 223 patients (130 males; mean age ± SD: 52.6 ± 12 years) were divided into training (148) and internal validation (75) cohorts. Dual scans were classified based on NETPET scores (D1-D3). Single 68Ga-DOTANOC and 18F-FDG PET-CT scans were stratified into S1-S3 and F1-F3 based on SUVmax. The NETPET score-based grading system demonstrated the best OS and PFS prediction (C-index, 0.763 vs. 0.727 vs. 0.566). Nomograms for OS and PFS exhibited superior prognostic performance in both cohorts (all AUCs > 0.8). New classification based on NETPET score predicts patient OS/PFS best. PET-CT-based nomograms show accurate OS/PFS forecasts.

Methane gas spectral imaging method based on dual wedge scanning mirrors

With the increase in the number of oil and gas pipelines laid in China, more attention needs to be paid to pipeline maintenance work. At present, the main methods of detecting natural gas leaks in oil and gas transmission stations include manual inspections, opposing natural gas detection equipment, and cloud desktop natural gas detection equipment. Hand held natural gas detection equipment is used for manual inspection, which requires regular manual inspection. However, the response speed is poor and gas leaks cannot be detected in a timely manner. The opposed laser gas detection method can only detect the presence of gas on the beam path. If a larger area of leakage detection is desired, more equipment needs to be installed, resulting in a greatly increase in hardware costs. The existing cloud desktop laser gas detection method controls the deflection of the laser beam through the cloud platform to achieve leak detection at various points in the area to be tested. However, the rotation speed of the cloud platform is slow, and a complete detection cycle takes dozens of minutes, and only the presence of gas can be detected. For accurate leak location, manual on-site survey is also required to further determine the leak location. In order to meet the needs of the real-time monitoring and rapid positioning of oil and gas pipeline leaks, in this work, a fast and accurately controlled dual wedge scanning mirror system is designed, which combines tunable semiconductor laser absorption spectroscopy technology to convert the gas measurement laser beam from point measurement to surface measurement, thereby obtaining the two-dimensional distribution of gas, which is conducive to subsequent analysis and positioning of gas leakage sources. By using the inverse solution iterative optimization algorithm, the angle of the wedge mirror is controlled to obtain an efficient and uniform beam scanning trajectory. The deflection direction and detection position of the laser beam are fused with the corresponding methane concentration information, and a methane concentration data containing position information is constructed. In order to quantitatively verify the measurement accuracy and spatial resolution in the experiment, a standard air bag is used to simulate the methane leakage distribution. The results show that the minimum detection limit of the system can be lower than 5×10&lt;sup&gt;–4&lt;/sup&gt; m, and the spatial resolution can be less than 6 cm. At the same time, this method can adjust the scanning step node based on the measurement distance of the oil from gas station, thereby achieving adjustable imaging resolution. This imaging method provides a new idea for accurately positioning and detecting the methane leakage location and amount.

Aperture Fed Microstrip Dual Polarization Wide Scan Phased Array Antenna With Mutual Coupling Reduction

Aperture Fed Microstrip Dual Polarization Wide Scan Phased Array Antenna With Mutual Coupling Reduction

Dual Frequency Multi-Functional via-Less Leaky Wave Antenna Featuring Enhanced Frequency Sensitivity and Dual Beam Scanning Capability

Dual Frequency Multi-Functional via-Less Leaky Wave Antenna Featuring Enhanced Frequency Sensitivity and Dual Beam Scanning Capability

Application of artificial intelligence-based dual source CT scanning in the differentiation of lung adenocarcinoma in situ and minimally invasive adenocarcinoma.

Lung adenocarcinoma is the most common type of lung cancer with highly incidence and mortality. Due to the overlap of morphological features, it is difficult to distinguish clinically between preinvasive lesions (in situ adenocarcinoma, AIS) and invasive lesions (minimally invasive adenocarcinoma, MIA), which appear as ground glass cloudy nodules. This study was performed to probe the application value of artificial intelligence (AI)-based dual source CT scanning in the differentiation of AIS as well as MIA. The clinical data of 136 patients in Shanghai Baoshan Hospital of Integrated Traditional Chinese and Western Medicine from January 2019 to January 2022 were retrospectively analyzed. The accuracy of AI in distinguishing lung AIS (n=76) and MIA (n=60) were analyzed. The effectiveness of AI in detecting nodules and its diagnostic efficacy for AIS and MIA were explored. The proportion of patients with clear and regular lesion boundaries in AIS was higher than that in MIA. The mean lesion diameter of AIS patients was shorter than MIA patients. There was no difference in the CT value between AIS and MIA in the ground glass nodule density area of pure ground glass nodule and mixed ground glass nodule, but the CT value of the solid nodule density area in AIS was lower. The occurrence of pulmonary vascular abnormality, air bronchogram sign, and pleural depression in AIS patients were lower than MIA patients. The detection rate of AI for lung adenocarcinoma with nodule diameter ≤ 5 mm, complete solid nodules and ground glass nodules was significantly higher than radiologists. The sensitivity, specificity, positive prediction rate, negative prediction rate and accuracy of AI detection were significantly higher than radiologists. AI-based dual source CT scanning can clearly show the morphological characteristics of lung adenocarcinoma, which is helpful for the differential diagnosis of lung AIS as well as MIA.