Tomography Research Articles

Size-specific dose estimates calculated using patient size measurements from scanned projection radiograph in high-resolution chest computed tomography.

Size-specific dose estimates (SSDE) are used to assess patient-specific radiation exposure in Computed Tomography (CT), complementing the volume CT dose index (CTDIvol). This study compared SSDE calculated using patient's lateral size from scan projection radiograph (SPR) with SSDE calculated using water equivalent diameter (Dw) from tomographic images in adult chest high-resolution CT (HRCT). In a single-centre study, the CTDIvol and dose-length product (DLP) were recorded from HRCT dose reports of adult patients. Lateral width (SLat), at the centre of the scan range, from the SPR was measured and the SSDE (SSDER) was calculated using conversion factors related to SLat. Average CT number, area of the slice, and lateral size of the patient (AxLat) were measured on the middle slice. The Dw and SSDE from Dw (SSDEW) were calculated. SSDER and SSDEW were compared using Wilcoxon signed rank test. Correlation between patient size and dosimetry parameters were investigated using Spearman Correlation test with statistical significance at P < 0.05. Bland-Altman plot was also used to test agreement between the two SSDE values. Median CTDIvol, DLP, SSDER and SSDEW were 11.0 mGy, 372 mGy.cm, 11.6 mGy and 12.9 mGy, respectively. Small but statistically significant differences (P < 0.03) were found between SLat and AxLat as well as between SSDER and SSDEW. Bland-Altman analysis resulted in borderline agreement between SSDE values. Moderate correlations were observed between dosimetry quantities and patient size measurements (ρ > 0.640; P < 0.001). SSDEw showed statistically significant correlation (ρ = 0.587 and P < 0.001) with SSDER. SSDER may be used to assess patients' absorbed radiation dose, before the scan, in adult chest HRCT. The median value of SSDER was about 10% lower than the median value SSDEW. However, the SSDEW should be used after the scan to establish effective dose and radiation risk to the patient.

Multiple-Input Multiple-Output Microwave Tomographic Imaging for Distributed Photonic Radar Network

This paper deals with the imaging problem from data collected by means of a microwave photonics-based distributed radar network. The radar network is leveraged on a centralized architecture, which is composed of one central unit (CU) and two transmitting and receiving dual-band remote radar peripherals (RPs), it is capable of collecting monostatic and multistatic phase-coherent data. The imaging is herein formulated as a linear inverse scattering problem and solved in a regularized way through the truncated singular value decomposition inversion scheme. Specifically, two different imaging schemes based on an incoherent fusion of the tomographic images or a fully coherent data processing are herein developed and compared. Experimental tests carried out in a port scenario for imaging both a stationary and a moving target are reported to validate the imaging approach.

Lung MRI: The future is now.

Tomographic imaging via MRI can capture structural abnormalities at high resolution and reveal functional abnormalities if acquired during respiration. In infants and children with chronic lung diseases, MRI can serve as a safe and effective tool to characterize cardiorespiratory disease where PFTs are not feasible. Functional lung imaging via hyperpolarized Xe MRI has been shown to have very high sensitivity to regional airway obstruction, changes in alveolar-airspace size/structure, and gas-exchange due to abnormalities in the interstitium or blood-flow; the technique is routinely used in ages 5 and up. This summary outlines each of the functional measures currently available using Xe MRI.

Neutrophil‑to‑lymphocyte ratio and risk of disease progression in patients with nivolumab‑treated unresectable or recurrent gastric cancer.

Studies have associated neutrophil-to-lymphocyte ratio (NLR) with overall survival (OS) and progression-free survival (PFS) in patients with gastric cancer (GC). The present study aimed to examine the relationship between dynamic changes in NLR during treatment and disease progression in patients with unresectable or recurrent GC treated with nivolumab monotherapy as a third-line or later regimen. Patients treated with nivolumab as a third-line or later therapy for unresectable or recurrent GC at Gifu University Hospital (Gifu, Japan) from April 2017 to December 2021 were included. Pretreatment data and those obtained every 2 weeks after the treatment commenced were evaluated. The association between all NLR values and disease progression for each patient was evaluated using a time-dependent Cox proportional hazards model and restricted cubic spline (RCS) curves. The study included 44 patients (23 men and 21 women). The response and disease control rates were 6.8 and 27.3%, respectively. The median PFS and OS of all patients were 1.84 months [95% confidence interval (CI), 1.32-2.14] and 5.93 months (95% CI, 3.75-10.75), respectively. The risk for progressive disease (PD) increased with higher NLR (hazard ratio, 2.25; 95% CI, 1.3-3.87). The RCS curves also indicated that the higher the NLR, the higher the risk for PD, especially if the NLR value was <3.0. NLR during treatment could predict the risk of PD, suggesting that NLR could be integrated with tumor markers, computed tomographic images and other modalities to enable treatment selection without delay.

Liver anatomy for totally laparoscopic segment 7 resection from a caudal magnified view-a 3-dimensional computed tomographic analysis.

Laparoscopic resection of hepatic segment 7 is considered particularly difficult. We analyzed anatomic variation of this segment in caudally oriented 3-dimensional (3D) magnified computed tomographic (CT) images obtained prior to liver resection. Analysis included 105 patients with preoperative 3D CT evaluation preceding liver resection for hepatobiliary malignancies between April 2021 and April 2024. Five ramification patterns were evident from a caudal magnified view. Some patients who had multiple segment 7 (S7) portal pedicles and an S7 pedicle branching ventrally posed difficulty in performing segmentectomy for the exact extent of S7. Distance from the point where a perpendicular line from the right rim of the inferior vena cava (IVC) intersected the right posterior portal pedicle to the point of bifurcation of the S6 and 7 pedicles was 34.6mm (range, 3.9-78.8; mean ± standard deviation, 35.2 ± 14.8mm). The median angle between the perpendicular line from the right rim of the IVC and the line from the root of the S7 pedicle to the right rim of the IVC was 77° (10-140); the mean ± standard deviation was 75.3° ± 28.1. Differences among ramification patterns also were evident. The angle between the right posterior portal pedicle and the S7 pedicle was 143° (79-215) or 143.3 ± 26.7, and that between S7 and S6 pedicles was 71°(15-123) or 75.5 ± 21.7°, representing relatively little variation. Understanding these details of caudal-view anatomy may resolve difficulties and clarify access required for exposing S7 portal pedicles.

Positron Emission Tomography/Computed Tomography Imaging in Therapeutic Clinical Trials in Alzheimer's Disease: AnOverview of the Current State of the Artof Research.

The integration of positron emission tomography/computed tomography (PET/CT) has revolutionized the landscape of Alzheimer's disease (AD) research and therapeutic interventions. By combining structural and functional imaging, PET/CT provides a comprehensive understanding of disease pathology and response to treatment assessment. PET/CT, particularly with 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG), facilitates the visualization of glucose metabolism in the brain, enabling early diagnosis, staging, and monitoring of neurodegenerative disease progression. The advent of amyloid and tau PET imaging has further propelled the field forward, offering invaluable tools for tracking pathological hallmarks, assessing treatment response, and predicting clinical outcomes. While some therapeutic interventions targeting amyloid plaque load showed promising results with the reduction of cerebral amyloid accumulation over time, others failed to demonstrate a significant impact of anti-amyloid agents for reducing the amyloid plaques burden in AD brains. Tau PET imaging has conversely fueled the advent of disease-modifying therapeutic strategies in AD by supporting the assessment of neurofibrillary tangles of tau pathology deposition over time. Looking ahead, PET imaging holds immense promise for studying additional targets such as neuroinflammation, cholinergic deficit, and synaptic dysfunction. Advances in radiotracer development, dedicated brain PET/CT scanners, and Artificial Intelligence-powered software are poised to enhance the quality, sensitivity, and diagnostic power of molecular neuroimaging. Consequently, PET/CT remains at the forefront of AD research, offering unparalleled opportunities for unravelling the complexities of the disease and advancing therapeutic interventions, although it is not yet enough alone to allow patients' recruitment in therapeutic clinical trials.

Application of X-Ray Computed Tomography to Identify Defects in Lost Wax Ceramic Moulds for Precision Casting of Turbine Blades.

This article presents the results of testing the suitability of X-ray computed tomography for the quality control of the casting moulds used for producing turbine blades. The research was focused on the analysis of cross-sectional images, spatial models and the porosity of moulds using a Phoenix L 450 microtomograph. The research material consisted of samples from three mixtures of ceramic materials and binders intended for producing casting moulds using the lost wax method. Various configurations of filling materials (Molochite and quartz flours) and binder (Remasol, Ludox PX 30 and hydrolysed ethyl silicate) mixtures were considered. X-ray computed tomography enabled the detection of a number of defects in the ceramic mass related to the distribution of mass components, porosity concentration and defects resulting from the specificity of the mould production. It was found that casting mould quality control on cross-sectional tomographic images is faster and as accurate as the analysis of three-dimensional models and allows for the detection of a whole range of ceramic defects, but the usefulness of the images is greatest only when the cross-sections are taken at an appropriate angle relative to the object being examined.

Morphometric Tomographic Analysis of the Head of the Tridactyl Humanoid Specimen from Nasca-Peru

Objective: To report the tomographic and morphometric analysis of the head of the tridactyl humanoid specimen from Nazca, Peru. Method: A qualitative case study approach. RadiAnt DICOM Viewer software version 4.2.1 was used to analyze lengths, diameters, and volume in tomographic images of the head. The morphological biometric analysis applied anthropometric methods using some craniometric points and cephalometric angles. Results and Discussion: As a result, it is reported that there are atypical, strange, and exceptional morphometric imaging features in the cephalic segment of specimen M01. The cephalometric analysis based on the ANB angle revealed a class II skeletal pattern, and according to the Bjorl-Jarabak analysis, it has a convex facial profile with hypodivergent growth (brachyfacial). The patient also has maxillary biprotrusion, severe protrusion of upper and lower incisors, loss of teeth, presence of root remnants, severe dental abrasion, non-assessable canine class, absence of three third molars and ocular protrusion. Based on craniometric points, the SNA angle (Sella, Nasion and Point A) and the SNB angle (Sella, Nasion and Point B) maxillary protrusion and mandibular protrusion were diagnosed. Implications of the research: It is concluded that the combination of uncommon morpho-anatomical features in the maxillofacial and cranial massif do not correspond to a human craniofacial biotype, but could be considered as suggestive findings of morpho-anatomical features typical of a hominid species similar to humans. Originality/Value: The expansion of biometric and morphoanatomical data of the head reinforces the hypothesis that morphologically it would be a non-human hybrid species.

Synchrotron X-ray imaging of soft biological tissues - principles, applications and future prospects.

Synchrotron-based tomographic phase-contrast X-ray imaging (SRµCT or SRnCT) is a versatile isotropic three-dimensional imaging technique that can be used to study biological samples spanning from single cells to human-sized specimens. SRµCT and SRnCT take advantage of the highly brilliant and coherent X-rays produced by a synchrotron light source. This enables fast data acquisition and enhanced image contrast for soft biological samples owing to the exploitation of phase contrast. In this Review, we provide an overview of the basics behind the technique, discuss its applications for biologists and provide an outlook on the future of this emerging technique for biology. We introduce the latest advances in the field, such as whole human organs imaged with micron resolution, using X-rays as a tool for virtual histology and resolving neuronal connections in the brain.

Adria microplate: a puzzling key stone in west-central Mediterranean geodynamics

The Mediterranean region denotes a special plate tectonic environment as the two big plates, Africa and Eurasia, primarily provide the main frame while the dominant players are the small oceanic basins and the continental micro plates (MP) that for the past 80 Ma was the Adria MP. In this environment slab rollback subduction, orogenic arc formation and rotation of crustal blocks are common. While the tectonic setting and involvement in geodynamic processes of Adria MP might not be unique in global terms, it presents Adria as an ideal natural laboratory to study the geodynamic processes individually and in their combined effects in a generally well-studied and rather wellaccessible region. The current extension of the Adria MP is defined by the continental Moho as far into the bounding orogens as the latter could be confirmed. The slabs surrounding Adria dominate and characterize the geodynamics of this MP and in most cases their geometries and the possible connection with Adria are well defined by tomographic images. The Ionian oceanic lithosphere slab subducting beneath Calabria has been torn off and detached from the very short South Apennines slab remaining attached to Adria. On the southeastern side we observe the Adria slab beneath the Hellenides that seems detached from the Ionian oceanic lithosphere slab of the Hellenic subduction zone. Along the Dinarides a slab gap is observed analogue to the slab window on Adria MP’s western side between the South Apennines and the North Apennines. Encircled by three orogens, the Adria continental lithosphere has been and still is strongly affected by the subductions surrounding it. In the northern part of the Adria MP, the North Apennines slab rollback is the obvious dominant geodynamic force acting locally on the plate while in contrast, the slabs beneath the Eastern Alps and beneath the Hellenides seem stagnant. This study presents a brief overview of the wealth of information aiming to summarize the main constraints on Adria MP available and it discusses some of the questions surrounding this key player in west-central Mediterranean geodynamics.

Moxifloxacin HCl -loaded Cellulose Acetate Butylate In Situ Forming Gel for Periodontitis Treatment.

Periodontitis presents significant treatment challenges due to its complexity and potential complications. In response, an in situ forming gel (ISG) loaded with moxifloxacin HCl (Mx) and cellulose acetate butyrate (CAB) was developed for targeted periodontitis therapy. Mx-loaded 10-45% CAB-based ISGs were developed, and their physicochemical properties such as rheology, viscosity, contact angle, gel morphology and gel formation, interface interaction were investigated. Moreover, the formulation performance studies including drug release and kinetics, in vitro degradation, and antimicrobial activities were also evaluated. The Mx-loaded ISGs containing 25-45% CAB demonstrated rapid matrix formation in both macroscopic and microscopic examinations and presented plastic deformation matrix. Tracking with sodium fluorescein and Nile red fluorescence probes indicated delayed solvent movement owing to CAB matrix formation. Adequate CAB content sustained Mx release for one week, following Peppas-Sahlin model and indicating a predominantly Fickian diffusion mechanism. Higher CAB content likely contributed to a denser matrix structure, leading to a slower in vitro degradation rate. Synchrotron radiation X-ray tomographic and SEM imaging provided insights into the CAB matrix structure and porous network formation. These ISG formulations effectively inhibited Staphylococcus aureus, Escherichia coli, Candida albicans, and Porphyromonas gingivalis. The Mx-loaded 40% CAB-based ISG shows promise as a dosage form for treating periodontitis. Further clinical trials are necessary to ensure the safety of this new ISG formulation, despite existing safety data for other medicinal uses of CAB. HIGHLIGHTS: Moxifloxacin HCl-loaded 10-45% cellulose acetate butyrate (CAB)-based in situ forming gels (ISG) were developed. They were evaluated for physicochemical properties, drug release, in vitro degradation, and antimicrobial activities. ISGs with 25-45% CAB showed swift matrix formation and plastic deformation Adequate CAB content sustained Mx release with Fickian diffusion mechanism They promise for periodontitis treatment because of effective inhibition of related pathogens.

Dynamic sparse x-ray nanotomography reveals ionomer hydration mechanism in polymer electrolyte fuel-cell catalyst.

Tomographic imaging of time-evolving samples is a challenging yet important task for various research fields. At the nanoscale, current approaches face limitations of measurement speed or resolution due to lengthy acquisitions. We developed a dynamic nanotomography technique based on sparse dynamic imaging and 4D tomography modeling. We demonstrated the technique, using ptychographic x-ray computed tomography as its imaging modality, on resolving the in situ hydration process of polymer electrolyte fuel cell (PEFC) catalyst. The technique provides a 40-time increase in temporal resolution compared to conventional approaches, yielding 28 nm half-period spatial and 12 min temporal resolution. The results allow a quantitative characterization of the water intake process inside PEFC catalysts with nanoscale resolution, which is crucial for understanding their electrochemical mechanisms and optimizing their performance. Our technique enables high-speed operando nanotomography studies and paves the way for wider application of dynamic tomography at the nanoscale.

Automatic maxillary sinus segmentation and pathology classification on cone-beam computed tomographic images using deep learning

BackgroundMaxillofacial complex automated segmentation could alternative traditional segmentation methods to increase the effectiveness of virtual workloads. The use of DL systems in the detection of maxillary sinus and pathologies will both facilitate the work of physicians and be a support mechanism before the planned surgeries.ObjectiveThe aim was to use a modified You Only Look Oncev5x (YOLOv5x) architecture with transfer learning capabilities to segment both maxillary sinuses and maxillary sinus diseases on Cone-Beam Computed Tomographic (CBCT) images.MethodsData set consists of 307 anonymised CBCT images of patients (173 women and 134 males) obtained from the radiology archive of the Department of Oral and Maxillofacial Radiology. Bilateral maxillary sinuses CBCT scans were used to identify mucous retention cysts (MRC), mucosal thickenings (MT), total and partial opacifications, and healthy maxillary sinuses without any radiological features.ResultsRecall, precision and F1 score values for total maxillary sinus segmentation were 1, 0.985 and 0.992, respectively; 1, 0.931 and 0.964 for healthy maxillary sinus segmentation; 0.858, 0.923 and 0.889 for MT segmentation; 0.977, 0.877 and 0.924 for MRC segmentation; 1, 0.942 and 0.970 for sinusitis segmentation.ConclusionThis study demonstrates that maxillary sinuses can be segmented, and maxillary sinus diseases can be accurately detected using the AI model.

Radiographic differences in deep fascial space infections versus localized acute apical abscesses: A cone-beam computed tomographic-based observational study

ABSTRACT Aim: The objective of this study was to evaluate anatomical differences and patterns of bone loss in patients with acute apical abscess (AAA) clinically presenting as a localized swelling or with concomitant fascial space involvement (FSI) using cone-beam computed tomographic (CBCT) imaging. Materials and Methods: Thirty CBCT images of AAA cases presenting with fascial space involvement (FSI) and 31 cases of localized acute apical abscess (LAAA) were evaluated. Factors that were recorded included the presence/absence of cortical disruption, the distance of the involved tooth apex to the buccal and lingual/palatal cortex, the length of the anatomic root/s of the involved tooth, and the volume of the endodontic lesions. Results: The median for the volume of the lesions was 138 mm3 for the FSI group and 154 mm3 for the LAAA group (P &gt; 0.05). Radiographic evidence of cortical disruption was seen in 26.7% of the cases with FSI and 41.9% of the cases with LAAA (P &gt; 0.05). The mean for the distance of the apex to the buccal cortex was the only statistically significant difference between the two groups and was 4.2 mm for the FSI group and 3 mm for the LAAA group (P &lt; 0.05). Conclusions: CBCT assessment showed root apices associated with fascial space involvement tended to be more confined in cancellous bone. Although a significant difference between the two conditions was found, the inflammatory process is complex, and CBCT assessment alone cannot predict AAA remaining as a localized swelling versus spreading to fascial spaces.

Regularity and correlation analysis of regional lymph node metastasis in nonoperative patients with non-small cell lung cancer based on positron emission tomography/computed tomography images

BackgroundDefinitive concurrent chemoradiotherapy (CCRT) is the standard treatment for locally advanced, inoperable non-small cell lung cancer (NSCLC). Previous studies have mainly focused on examining local failure and recurrence patterns after surgery and the principles of lymph node metastasis (LNM) in surgical candidates with NSCLC. However, these studies were just only able to guide postoperative radiotherapy (PORT) and the patterns of LNM in patients with resected NSCLC was inadequate to represent that in locally advanced inoperable NSCLC patients for guiding target volume delineation of CCRT. In this study, we aimed to analyze the metastasis regularities and establish the correlations between different lymph node levels in NSCLC patients without any intervention using positron emission tomography/computed tomography (PET/CT) images.MethodsOverall, 358 patients with N1–N3 NSCLC admitted in our hospital between 2018 and 2022 were retrospectively analyzed. The diagnosis of metastatic lymph nodes was reviewed and determined using the European Organization for Research and Treatment of Cancer standard and the standardized value of the PET/CT examination. Univariate and multivariate analysis were performed to investigate the correlations between the different levels were evaluated by using of the chi-square test and logistic regression model.ResultsThe lymph nodes with the highest metastasis rates in patients with left lung cancer were in order as follows: 10L, 4L, 5, 4R, and 7; while in those with right lung cancer they were 10R, 4R, 7, 2R, and 1R. Notably, we found left lung patients were more likely to have contralateral hilar, mediastinal and supraclavicular lymph nodes involved, and the right lung group exhibited a higher propensity for ipsilateral mediastinum and supraclavicular lymph node invasion. Furthermore, correlation analysis revealed there were significant correlative patterns in the LNM across different levels.ConclusionsThis study elucidated the patterns of primary LNM in patients with NSCLC who had not undergone surgery (without any treatment interventions) and the correlations between lymph node levels. These findings were expected to provide useful reference for target volume delineation in definitive concurrent chemoradiotherapy in locally advanced NSCLC patients.

Calcifying epithelial odontogenic tumour with an atypical clinical presentation in a paediatric patient: A case report and literature review

AbstractAimWe report a rare case of a calcifying epithelial odontogenic tumour with atypical clinical presentation in an adolescent and present a literature review of this tumour in paediatric patients.Materials and MethodsA 12‐year‐old female patient presented with a painless swelling of the left mandible, with a history of 6 months. Clinical examination revealed a sessile mass with a reddish‐pink colour and firm consistency. Tomographic images showed a hypodense, unilocular lesion involving unerupted tooth #34, with a hyperdense focus in contact with the tooth crown disrupting the buccal cortex.ResultsEnucleation, curettage and peripheral osteotomy of the lesion were performed, and the impacted tooth was removed, followed by the application of autologous leucocyte and platelet‐rich fibrin matrices to the region. The patient evolved favourably with good clinical healing and evidence of new bone formation.ConclusionsDespite its aggressive potential, the conservative approach for CEOT in paediatric patients proved to be effective. Our review found reports of recurrence up to 13 years after surgery. Therefore, long‐term clinical and radiographical follow‐up is indicated.

Untargeted Lipidomics Reveals Novel HDL Metabotypes and Lipid-Clinical Correlates

Plasma high-density lipoprotein (HDL), originally studied for its role in lipid transport, is now appreciated to have wide-ranging biological functions that become defective during disease. While >200 lipids have collectively been detected in HDL, published HDL lipidomic analyses in different diseases have commonly been targeted to prespecified subsets of lipids. Here, we report the results of untargeted lipidomic analysis of HDL isolated from 101 subjects referred for computed tomographic coronary imaging for whom multiple additional clinical and lipoprotein metadata were measured. Unsupervised clustering of the total HDL lipidome revealed that the subjects fell into one of two discrete groups, herein referred to as HDL ‘metabotypes’. Subjects in metabotype 1 were likelier to be female and tended to have a less atherogenic lipoprotein profile, higher HDL cholesterol efflux capacity (CEC), and lower-grade non-calcified burden on coronary imaging than metabotype 2 counterparts. Specific lipids were relatively enriched in metabotype 1 HDL. Linear modeling revealed that several of these lipids were positively associated with CEC, statin use, HDL size, and HDL particle number, and positively correlated with HDL apolipoprotein A-1, suggesting that they may be informative HDL biomarkers. Taken together, we posit a novel, clinically relevant categorization for HDL revealed by systems biology.

Volumetric correlation of periapical lesion with Orstavik’s periapical index: A retrospective cone-beam computed tomographic study

Abstract Aim: To assess the correlation among cone-beam computed tomographic periapical volume index (CBCTPAVI) and periapical lesion volume with Orstavik’s periapical index (PAI). Methodology: Seventy-six cone-beam computed tomographic (CBCT) and periapical radiographic images of single-rooted teeth presenting with apical periodontitis from 42 patients were obtained from a period of March 2023 to April 2024. Two observers evaluated the periapical radiographs and assigned PAI scores. CBCTPAVI was allocated based on the volume of the lesion, which was computed using ITK-SNAP software. Spearman’s correlation coefficient was employed to evaluate the association between CBCTPAVI and lesion volume with PAI. Results: A significant and moderate positive relationship between PAI and lesion volume (ρ = 0.553, P &lt; 0.001) as well as between PAI and CBCTPAVI (ρ = 0.506; P &lt; 0.001) was observed. Conclusion: The risk of under/overestimation of results on two-dimensional periapical radiographs exists, despite a favorable connection with volumetric assessment of CBCT images.

Optical signal characteristics analysis of atmospheric disturbance density fields generated by high-speed aircraft

Aircraft disturbs the adjacent atmospheric environment in flight, forming spatial distribution features of atmospheric density that differ from the natural background, which may potentially be utilized as tracer characteristics to introduce new technologies for indirectly sensing the presence of aircraft. In this paper, the concept of a long-range aircraft detection based on the atmospheric disturbance density field is proposed, and the detection mode of tomographic imaging of the scattering light of an atmospheric disturbance flow field is designed. By modeling the spatial distribution of the disturbance density field, the scattered echo signal images of active light towards the disturbance field at long distance are simulated. On this basis, the characteristics of the disturbance optical signal at the optimal detection resolution are analyzed. The results show that the atmospheric disturbance flow field of the supersonic aircraft presents circular in the light-scattering echo images. The disturbance signal can be further highlighted by differential processing of the adjacent scattering images. As the distance behind the aircraft increases, the diffusion range of the disturbance signal increases, and the signal intensity and contrast with the background decrease. Under the ground-based observation conditions of the aircraft at a height of 10000 m, a Mach number of 1.6, and a detection distance of 100 km, the contrast between the disturbance signal and the background was 30 dB at a distance of one time from the rear of the fuselage, and the diffusion diameter of the disturbance signal was 50 m. At a distance eight times the length of the aircraft, the contrast decreased to 10 dB, and the diameter increased to 290 m. The contrast was reduced to 3 dB at a distance nine times the length of the aircraft, and the diameter was diffused to 310 m. These results indicate the possibility of long-range aircraft detection based on the characteristics of the atmospheric density field.

A reconfigurable and conformal liquid sensor for ambulatory cardiac monitoring

The severe mismatch between solid bioelectronics and dynamic biological tissues has posed enduring challenges in the biomonitoring community. Here, we developed a reconfigurable liquid cardiac sensor capable of adapting to dynamic biological tissues, facilitating ambulatory cardiac monitoring unhindered by motion artifacts or interference from other biological activities. We employed an ultrahigh-resolution 3D scanning technique to capture tomographic images of the skin on the wrist. Then, we established a theoretical model to gain a deep understanding of the intricate interaction between our reconfigurable sensor and dynamic biological tissues. To properly elucidate the advantages of this sensor, we conducted cardiac monitoring alongside benchmarks such as the electrocardiogram. The liquid cardiac sensor was demonstrated to produce stable signals of high quality (23.1 dB) in ambulatory settings.