Apex Images Research Articles

Precision Medicine for Apical Lesions and Peri-Endo Combined Lesions Based on Transfer Learning Using Periapical Radiographs.

An apical lesion is caused by bacteria invading the tooth apex through caries. Periodontal disease is caused by plaque accumulation. Peri-endo combined lesions include both diseases and significantly affect dental prognosis. The lack of clear symptoms in the early stages of onset makes diagnosis challenging, and delayed treatment can lead to the spread of symptoms. Early infection detection is crucial for preventing complications. PAs used as the database were provided by Chang Gung Memorial Medical Center, Taoyuan, Taiwan, with permission from the Institutional Review Board (IRB): 02002030B0. The tooth apex image enhancement method is a new technology in PA detection. This image enhancement method is used with convolutional neural networks (CNN) to classify apical lesions, peri-endo combined lesions, and asymptomatic cases, and to compare with You Only Look Once-v8-Oriented Bounding Box (YOLOv8-OBB) disease detection results. The contributions lie in the utilization of database augmentation and adaptive histogram equalization on individual tooth images, achieving the highest comprehensive validation accuracy of 95.23% with the ConvNextv2 model. Furthermore, the CNN outperformed YOLOv8 in identifying apical lesions, achieving an F1-Score of 92.45%. For the classification of peri-endo combined lesions, CNN attained the highest F1-Score of 96.49%, whereas YOLOv8 scored 88.49%.

Semi-Automated Computational Assessment of Cancer Organoid Viability Using Rapid Live-Cell Microscopy.

The creation of patient-derived cancer organoids represents a key advance in preclinical modeling and has recently been applied to a variety of human solid tumor types. However, conventional methods used to assess in vivo tumor tissue treatment response are poorly suited for the evaluation of cancer organoids because they are time-intensive and involve tissue destruction. To address this issue, we established a suite of 3-dimensional patient-derived glioma organoids, treated them with chemoradiotherapy, stained organoids with non-toxic cell dyes, and imaged them using a rapid laser scanning confocal microscopy method termed “Apex Imaging.” We then developed and tested a fragmentation algorithm to quantify heterogeneity in the topography of the organoids as a potential surrogate marker of viability. This algorithm, SSDquant, provides a 3-dimensional visual representation of the organoid surface and a numerical measurement of the sum-squared distance (SSD) from the derived mass center of the organoid. We tested whether SSD scores correlate with traditional immunohistochemistry-derived cell viability markers (cellularity and cleaved caspase 3 expression) and observed statistically significant associations between them using linear regression analysis. Our work describes a quantitative, non-invasive approach for the serial measurement of patient-derived cancer organoid viability, thus opening new avenues for the application of these models to studies of cancer biology and therapy.

TMOD-06. CREATION OF PATIENT-DERIVED LOWER GRADE GLIOMA ORGANOID MODELS FOR PERSONALIZED TREATMENT RESPONSE ASSESSMENT

Abstract Creating in vitro models of lower grade glioma represents a major challenge in neuro-oncology research. There are few such models that are tractable and widely used, which has hindered understanding of the biology of these tumors. Recently, substantial progress has been made in generating patient-derived in vitro organoid models of high grade glioma, but modeling lower grade disease remains difficult. Based on our experience creating neurosphere cultures of lower grade astrocytomas from genetically engineered mice, we hypothesized that modifying patient-derived organoid generation protocols to incorporate physiological oxygen levels would allow establishment and propagation of lower grade glioma organoids. In this study, we show that this approach supports efficient organoid model generation from primary glioma specimens across all histological subtypes and tumor grades (WHO Grade I-IV, n = 20). These organoid models retain key characteristics of their respective parental tumors, including IDH mutations and other genetic alterations, metabolite profiles, intratumoral heterogeneity, cellular composition, and cytoarchitectural features. Importantly, lower grade glioma organoids can be cultured for months and reanimated after biobanking. Our high success rate ( >90%) in establishing organoid models from primary lower grade glioma tissue samples further highlighted opportunities for treatment response assessments. To perform longitudinal measurements of therapy-induced changes in glioma organoid viability, we designed a novel, non-invasive imaging assay (termed rapid apex imaging) to determine real-time treatment response in low and high grade gliomas. We evaluated longitudinal responses of glioblastoma and IDH1 R132H-positive Grade II astrocytoma organoids to temozolomide and olaparib with and without radiation treatment. We quantified topological changes in organoid structure by building a bioinformatics tool to translate imaging data into a cellularity metric as a biomarker of organoid response. Our work unveils an effective new method to create in vitro, personalized models of lower grade glioma that supports elucidation of treatment sensitivity profiles.

Micro‐expression recognition by two‐stream difference network

Facial micro-expression is a superposition of micro-expression features and identity information of a subject. For the problem of identity information interference in micro-expression recognition, this study proposes a new method for facial micro-expression recognition by de-identity information, called two-stream difference network (TSDN). First, a two-stream encoder-decoder network is trained by a convolutional neural network, where the input of the micro-expression stream is a micro-expression image, and the identity stream is a facial identity image. The micro-expression image is the apex image, and the identity image is the onset image in the micro-expression sequence. The identity information and micro-expression features are recorded in the intermediate layer of the micro-expression stream, while the intermediate layer of the identity stream contains only the identity information of a subject. Then, the identity information is removed by the difference network, but micro-expression features are stored in the intermediate layer of the micro-expression stream. Given the sequence of the micro-expressions, the TSDN model of de-identity information learns the difference that stores in the expression stream. Two public spontaneous facial micro-expression data sets (SMIC and CASME II) are employed in our experiments. The experiment results show that our model can achieve a superior performance in micro-expression recognition.

The value of left ventricular angiography in the diagnosis of apical hypertrophic cardiomyopathy

Objective To assess the diagnostic value of left ventricular angiography in patients with apical hypertrophic cardiomyopathy. Methods A total of 32 consecutively recruited patients aged from 61 to 78 with suspected apical hypertrophic cardiomyopathy from inconclusive apex imaging on conventional echocardiography from June 2016 to December 2017 underwent left ventricular opacification.A diagnosis of apical hypertrophic cardiomyopathy was made when the thickness of hypertrophied area of the apex was >1.5 cm, the ratio of the hypertrophied area to the non-hypertrophied area was >1.3, and no hypertrophy was found elsewhere. Results Twenty-four out of 32 patients (75.0%) were diagnosed with apical hypertrophic cardiomyopathy, all of whom had pure apical hypertrophy.The other 8 patients were excluded, with normal thickness in the apex.Patients with apical hypertrophic cardiomyopathy had apical wall thicknesses ranging from 15 mm to 21 mm, reduced myocardial motion amplitude in the apex and uneven echo at certain areas of the ventricular wall.All cases showed clear images of the apex with left ventricular opacification, and the apex of the heart lost its normal morphology and showed a pointed end, with ventricular cavity obliteration or uneven wall thickness in the apex. Conclusions Left heart ventricular angiography can be complimentary to conventional echocardiography in the diagnosis of apical hypertrophic cardiomyopathy by providing a clearer endocardial contour and more accurate estimates of apical wall thickness and therefore enhancing the diagnostic value of ultrasound for apical hypertrophic cardiomyopathy. Key words: Cardiomyopathy, hypertrophic; Echocardiography; Angiocardiography

Mineral Mapping Using the Automatized Gaussian Model (AGM)—Application to Two Industrial French Sites at Gardanne and Thann

The identification and mapping of the mineral composition of by-products and residues on industrial sites is a topic of growing interest because it may provide information on plant-processing activities and their impact on the surrounding environment. Imaging spectroscopy can provide such information based on the spectral signatures of soil mineral markers. In this study, we use the automatized Gaussian model (AGM), an automated, physically based method relying on spectral deconvolution. Originally developed for the short-wavelength infrared (SWIR) range, it has been extended to include information from the visible and near-infrared (VNIR) range to take iron oxides/hydroxides into account. We present the results of its application to two French industrial sites: (i) the Altéo Environnement site in Gardanne, southern France, dedicated to the extraction of alumina from bauxite; and (ii) the Millennium Inorganic Chemicals site in Thann, eastern France, which produces titanium dioxide from ilmenite and rutile, and its associated Séché Éco Services site used to neutralize the resulting effluents, producing gypsum. HySpex hyperspectral images were acquired over Gardanne in September 2013 and an APEX image was acquired over Thann in June 2013. In both cases, reflectance spectra were measured and samples were collected in the field and analyzed for mineralogical and chemical composition. When applying the AGM to the images, both in the VNIR and SWIR ranges, we successfully identified and mapped minerals of interest characteristic of each site: bauxite, Bauxaline® and alumina for Gardanne; and red and white gypsum and calcite for Thann. Identifications and maps were consistent with in situ measurements.

P5-4 - Usefulness of Multidetector Computed Tomography and Magnetic Resonance Imaging on Diagnosing Left Ventricular Noncompaction

Introduction: Left ventricular nonconpaction (LVNC) is classified as primary cardiomyopathy. Because of its poor outcome, the diagnosis of LVNC is important. However, not all LVNC patient could be diagnosed only by echocardiography mostly due to the limitation in obtaining reliable apex image. We experienced a LVNC patient who could be diagnosed using the multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in addition to echocardiography. Case: A 48 year-old male was admitted to our hospital because of left paralysis and NYHA 4 exertional breathlessness. He was diagnosed cerebral infarction (CI) and acute heart failure (AHF) accompanying tachycardiac atrial fibrillation (AF). AHF was compensated by carvedilol, enalapril with LV ejection fraction improvement from 22% to 61%. Echocardiography revealed dilated cardiomyopathy like heart and non-compacted layer in lateral side of apex even though the diagnostic image for LVNC could not be obtained. We conducted MDCT and MRI to obtain clear tangent image at apex; and diagnosed LVNC with the non-compaction/compaction ratio of 2.8, 3.5 respectively. The anticoagulant therapy and optical medical therapy were continued even after AF eradication by pulmonary vein isolation, this patient has spent 6 months free from any adverse cardiovascular events. Conclusion: MDCT and MRI should be considered when echocardiography cannot provide diagnostic image for LVNC.

Location- and Time-Specific Hydrological Simulations with Multi-Resolution Remote Sensing Data in Urban Areas

A major challenge in hydrologic modeling remains the mapping of vegetation dynamics in an urban landscape. The impact of vegetation on interception storage varies over time and needs to be quantified in order to enable proper management of water resources in urban areas. However, the heterogeneity and complexity of the urban landscape makes it challenging to monitor urban vegetation. A more detailed spatial and temporal scale is needed. To characterize surface cover at a high spatial resolution, a hyperspectral APEX image (2 m) is used, while a time series of Proba-V images (daily, 100 m) allows a detailed characterization of the seasonal variation of urban greenness. For this study, we use and validate the leaf area index (LAI) maps derived from APEX and Proba-V data for a selected pixel in the Watermaelbeek catchment in Brussels (Belgium). The ground-truthing of the Proba-V pixels includes a detailed mapping of land cover characteristics and more specifically vegetation cover throughout the seasons. LAI values calculated based on the APEX image agree with the LAI values measured from the ground (n = 106, R 2 = 0.68). Further, the aggregated APEX pixels correlate with the Proba-V pixels ( R 2 = 0.79), and the Proba-V data can be used to monitor vegetation dynamics. As the seasonal LAI measurements correspond with the Proba-V dynamics, we conclude that Proba-V images allow the characterization of vegetation dynamics at a high spatial resolution in heterogeneous areas. We create a time series of LAI maps at a high resolution (2 m), which allows a location- and time-specific simulation of interception storage and thus contributes to managing water resources in urban areas.

Comparison of support vector machine, random forest and neural network classifiers for tree species classification on airborne hyperspectral APEX images

ABSTRACTKnowledge of tree species composition in a forest is an important topic in forest management. Accurate tree species maps allow for much more detailed and in-depth analysis of biophysical forest variables. The paper presents a comparison of three classification algorithms: support vector machines (SVM), random forest (RF) and artificial neural networks (ANN) for tree species classification using airborne hyperspectral data from the Airborne Prism EXperiment sensor. The aim of this paper is to evaluate the three nonparametric classification algorithms (SVM, RF and ANN) in an attempt to classify the five most common tree species of the Szklarska Poręba area: spruce (Picea alba L. Karst), larch (Larix decidua Mill.), alder (Alnus Mill), beech (Fagus sylvatica L.) and birch (Betula pendula Roth). To avoid human introduced biases a 0.632 bootstrap procedure was used during evaluation of each compared classifier. Of all compared classification results, ANN achieved the highest median overall classification accuracy (77%) followed by SVM with 68% and RF with 62%. Analysis of the stability of results concluded that RF and SVM had the lowest variance of overall accuracy and kappa coefficient (12 percentage points) while ANN had 15 percentage points variance in results.

An Algorithm for In-Flight Spectral Calibration of Imaging Spectrometers

Accurate spectral calibration of satellite and airborne spectrometers is essential for remote sensing applications that rely on accurate knowledge of center wavelength (CW) positions and slit function parameters (SFP). We present a new in-flight spectral calibration algorithm that retrieves CWs and SFPs across a wide spectral range by fitting a high-resolution solar spectrum and atmospheric absorbers to in-flight radiance spectra. Using a maximum a posteriori optimal estimation approach, the quality of the fit can be improved with a priori information. The algorithm was tested with synthetic spectra and applied to data from the APEX imaging spectrometer over the spectral range of 385–870 nm. CWs were retrieved with high accuracy (uncertainty <0.05 spectral pixels) from Fraunhofer lines below 550 nm and atmospheric absorbers above 650 nm. This enabled a detailed characterization of APEX’s across-track spectral smile and a previously unknown along-track drift. The FWHMs of the slit function were also retrieved with good accuracy (<10% uncertainty) for synthetic spectra, while some obvious misfits appear for the APEX spectra that are likely related to radiometric calibration issues. In conclusion, our algorithm significantly improves the in-flight spectral calibration of APEX and similar spectrometers, making them better suited for the retrieval of atmospheric and surface variables relying on accurate calibration.

The application of APEX images in the assessment of the state of non-forest vegetation in the Karkonosze Mountains

Abstract Information about vegetation condition is needed for the effective management of natural resources and the estimation of the effectiveness of nature conservation. The aim of the study was to analyse the condition of non-forest mountain communities: synanthropic communities and natural grasslands. UNESCO’s M&B Karkonosze Transboundary Biosphere Reserve was selected as the research area. The analysis was based on 40 field test polygons and APEX hyperspectral images. The field measurements allowed the collection of biophysical parameters - Leaf Area Index (LAI), fraction of Absorbed Photosynthetically Active Radiation (fAPAR) and chlorophyll content - which were correlated with vegetation indices calculated using the APEX images. Correlations were observed between the vegetation indices (general condition, plant structure) and total area of leaves (LAI), as well as fraction of Absorbed Photosynthetically Active Radiation (fAPAR). The outcomes show that the non-forest communities in the Karkonosze are in good condition, with the synanthropic communities characterised by better condition compared to the natural communities.

Remote sensing of phytoplankton-macrophyte coexistence in shallow hypereutrophic fluvial lakes

We investigated with remote sensing (APEX images) the coexistence of phytoplankton and macrophytes in three interconnected shallow and hypereutrophic fluvial lakes (Mantua Lakes, Northern Italy). High concentrations of chlorophyll-a, up to 60 mg m−3, were determined in the open water between well-developed stands of floating-leaved, submerged, and emergent macrophytes. Our data suggest a general inhibition of phytoplankton by macrophytes, evidenced by decreasing chlorophyll-a concentrations in proximity of macrophyte stands. Chlorophyll-a concentrations halved in the proximity of emergent stands (~6 mg m−3 within 21 m from the stand border) when compared to the outer zones (~13 mg m−3). Contrasting trends were observed for submerged stands, where concentrations decreased inwards from ~8 to ~3 mg m−3. Floating leaved stands had a neutral effect, chlorophyll-a being nearly constant in both inner and outer zones. Overall, remotely-sensed data allow evaluation of quantitative and spatially defined interactions of macrophytes and phytoplankton at the whole ecosystem scale.

Growth and molecular responses to long‐distance stimuli in poplars: bending vs flame wounding

Inter-organ communication is essential for plants to coordinate development and acclimate to mechanical environmental fluctuations. The aim of this study was to investigate long-distance signaling in trees. We compared on young poplars the short-term effects of local flame wounding and of local stem bending for two distal responses: (1) stem primary growth and (2) the expression of mechanoresponsive genes in stem apices. We developed a non-contact measurement method based on the analysis of apex images in order to measure the primary growth of poplars. The results showed a phased stem elongation with alternating nocturnal circumnutation phases and diurnal growth arrest phases in Populus tremula × alba clone INRA 717-1B4. We applied real-time polymerase chain reaction (RT-PCR) amplifications in order to evaluate the PtaZFP2, PtaTCH2, PtaTCH4, PtaACS6 and PtaJAZ5 expressions. The flame wounding inhibited primary growth and triggered remote molecular responses. Flame wounding induced significant changes in stem elongation phases, coupled with inhibition of circumnutation. However, the circadian rhythm of phases remained unaltered and the treated plants were always phased with control plants during the days following the stress. For bent plants, the stimulated region of the stem showed an increased PtaJAZ5 expression, suggesting the jasmonates may be involved in local responses to bending. No significant remote responses to bending were observed.

Analyses of a Multimodal Spontaneous Facial Expression Database

Creating a large and natural facial expression database is a prerequisite for facial expression analysis and classification. It is, however, not only time consuming but also difficult to capture an adequately large number of spontaneous facial expression images and their meanings because no standard, uniform, and exact measurements are available for database collection and annotation. Thus, comprehensive first-hand data analyses of a spontaneous expression database may provide insight for future research on database construction, expression recognition, and emotion inference. This paper presents our analyses of a multimodal spontaneous facial expression database of natural visible and infrared facial expressions (NVIE). First, the effectiveness of emotion-eliciting videos in the database collection is analyzed with the mean and variance of the subjects' self-reported data. Second, an interrater reliability analysis of raters' subjective evaluations for apex expression images and sequences is conducted using Kappa and Kendall's coefficients. Third, we propose a matching rate matrix to explore the agreements between displayed spontaneous expressions and felt affective states. Lastly, the thermal differences between the posed and spontaneous facial expressions are analyzed using a paired-samples t-test. The results of these analyses demonstrate the effectiveness of our emotion-inducing experimental design, the gender difference in emotional responses, and the coexistence of multiple emotions/expressions. Facial image sequences are more informative than apex images for both expression and emotion recognition. Labeling an expression image or sequence with multiple categories together with their intensities could be a better approach than labeling the expression image or sequence with one dominant category. The results also demonstrate both the importance of facial expressions as a means of communication to convey affective states and the diversity of the displayed manifestations of felt emotions. There are indeed some significant differences between the temperature difference data of most posed and spontaneous facial expressions, many of which are found in the forehead and cheek regions.

Finite element simulation and analytical analysis for nano field emission sources that terminate with a single atom: A new perspective on nanotips

Nanotips are highly demanded for various applications in nanotechnology. For instance, nanotips with a single atom end can be used as a source of self collimated electron or ion beams. Such tips are usually characterized in the field ion microscope (FIM) or the field emission microscope (FEM), where only a top view can be captured and analyzed. We have noticed that single atom tips fabricated by different methods produce electrons in FEM mode, or ions in FIM mode, at a wide range of applied voltages for the respective mode. In this work we present numerical and analytical analyses to the distribution of the electric field in the vicinity of the nanotip apex that holds the topmost single atom. We demonstrate that although the electric field is relatively enhanced by the nano protrusion it is still significantly dominated by the tip base. The analyses explicitly show that nanotips with broad bases produce even less field than some modest tips, at the same applied voltage. This pronounced effect of the tip base accounts for the relatively high voltages needed at the imaging threshold field. The results reveal that single atom tips are not necessarily sharp at a mesoscopic scale and the tip sharpness has to be determined from the combination of the nanotip apex (FIM or FEM) image and the applied voltage.

Dynamic soft encoded patterns for facial event analysis

In this paper, we propose a new feature: dynamic soft encoded pattern (DSEP) for facial event analysis. We first develop similarity features to describe complicated variations of facial appearance, which take similarities between a haar-like feature in a given image and the corresponding ones in reference images as feature vector. The reference images are selected from the apex images of facial expressions, and the k-means clustering is applied to the references. We further perform a temporal clustering on the similarity features to produce several temporal patterns along the temporal domain, and then we map the similarity features into DSEP to describe the dynamics of facial expressions, as well as to handle the issue of time resolution. Finally, boosting-based classifier is designed based on DSEPs. Different from previous works, the proposed method makes no assumption on the time resolution. The effectiveness is demonstrated by extensive experiments on the Cohn–Kanade database.

Apex echocardiography. A two-dimensional technique for evaluating congenital heart disease.

We have evaluated apex echocardiography, using an 80 degrees phased array sector scanner, in 368 patients with congenital heart disease. With the patient lying with the left side dependent, the transducer is placed over the apex of the heart and cross sectional images are obtained in the plane perpendicular to the cardiac septa and through the orifices of the mitral and tricuspid valves. In this view, the chambers are side by side and both atria and ventricles are separated by their respective septa and atrioventricular valves. Defects in the region of the septa can be detected. Congenital defects involving the atrioventricular valves, such as endocardial cushion defects, tricuspid atresia, and Ebstein's anomaly, can be defined. The location of the baffle after Mustard's operation for aortopulmonary transposition and intra-atrial structures, such as the membrance in cor triatriatum, can be seen. The position of the apex of the heart can be located in dextro, levo, or mesocardia by definition of the apex image. The relative size of the ventricular septum can be identified with the apex image. We have found this technique to be valuable in patients with congenital heart disease who are undergoing cross sectional echocardiography.