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1.
Cell ; 185(19): 3551-3567.e39, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-36055250

RESUMO

Interactions between cells are indispensable for signaling and creating structure. The ability to direct precise cell-cell interactions would be powerful for engineering tissues, understanding signaling pathways, and directing immune cell targeting. In humans, intercellular interactions are mediated by cell adhesion molecules (CAMs). However, endogenous CAMs are natively expressed by many cells and tend to have cross-reactivity, making them unsuitable for programming specific interactions. Here, we showcase "helixCAM," a platform for engineering synthetic CAMs by presenting coiled-coil peptides on the cell surface. helixCAMs were able to create specific cell-cell interactions and direct patterned aggregate formation in bacteria and human cells. Based on coiled-coil interaction principles, we built a set of rationally designed helixCAM libraries, which led to the discovery of additional high-performance helixCAM pairs. We applied this helixCAM toolkit for various multicellular engineering applications, such as spherical layering, adherent cell targeting, and surface patterning.


Assuntos
Bactérias , Peptídeos , Humanos , Peptídeos/química
2.
Cell ; 180(4): 780-795.e25, 2020 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-32059781

RESUMO

The cerebral vasculature is a dense network of arteries, capillaries, and veins. Quantifying variations of the vascular organization across individuals, brain regions, or disease models is challenging. We used immunolabeling and tissue clearing to image the vascular network of adult mouse brains and developed a pipeline to segment terabyte-sized multichannel images from light sheet microscopy, enabling the construction, analysis, and visualization of vascular graphs composed of over 100 million vessel segments. We generated datasets from over 20 mouse brains, with labeled arteries, veins, and capillaries according to their anatomical regions. We characterized the organization of the vascular network across brain regions, highlighting local adaptations and functional correlates. We propose a classification of cortical regions based on the vascular topology. Finally, we analysed brain-wide rearrangements of the vasculature in animal models of congenital deafness and ischemic stroke, revealing that vascular plasticity and remodeling adopt diverging rules in different models.


Assuntos
Adaptação Fisiológica , Encéfalo/irrigação sanguínea , Capilares/anatomia & histologia , Artérias Cerebrais/anatomia & histologia , Veias Cerebrais/anatomia & histologia , Remodelação Vascular , Animais , Capilares/patologia , Artérias Cerebrais/patologia , Veias Cerebrais/patologia , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Privação Sensorial , Estresse Psicológico/etiologia , Estresse Psicológico/patologia , Acidente Vascular Cerebral/patologia
3.
Annu Rev Cell Dev Biol ; 35: 655-681, 2019 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-31299171

RESUMO

The ability to visualize and quantitatively measure dynamic biological processes in vivo and at high spatiotemporal resolution is of fundamental importance to experimental investigations in developmental biology. Light-sheet microscopy is particularly well suited to providing such data, since it offers exceptionally high imaging speed and good spatial resolution while minimizing light-induced damage to the specimen. We review core principles and recent advances in light-sheet microscopy, with a focus on concepts and implementations relevant for applications in developmental biology. We discuss how light-sheet microcopy has helped advance our understanding of developmental processes from single-molecule to whole-organism studies, assess the potential for synergies with other state-of-the-art technologies, and introduce methods for computational image and data analysis. Finally, we explore the future trajectory of light-sheet microscopy, discuss key efforts to disseminate new light-sheet technology, and identify exciting opportunities for further advances.


Assuntos
Biologia do Desenvolvimento/métodos , Microscopia de Fluorescência/tendências , Animais , Simulação por Computador , Compressão de Dados , Desenvolvimento Embrionário , Humanos , Processamento de Imagem Assistida por Computador/métodos , Microscopia de Fluorescência/instrumentação , Microscopia de Fluorescência/métodos , Análise de Célula Única/métodos , Análise Espaço-Temporal
4.
Annu Rev Biochem ; 84: 499-517, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25747402

RESUMO

About 20 years ago, the first three-dimensional (3D) reconstructions at subnanometer (<10-Å) resolution of an icosahedral virus assembly were obtained by cryogenic electron microscopy (cryo-EM) and single-particle analysis. Since then, thousands of structures have been determined to resolutions ranging from 30 Å to near atomic (<4 Å). Almost overnight, the recent development of direct electron detectors and the attendant improvement in analysis software have advanced the technology considerably. Near-atomic-resolution reconstructions can now be obtained, not only for megadalton macromolecular complexes or highly symmetrical assemblies but also for proteins of only a few hundred kilodaltons. We discuss the developments that led to this breakthrough in high-resolution structure determination by cryo-EM and point to challenges that lie ahead.


Assuntos
Microscopia Crioeletrônica/métodos , Microscopia Crioeletrônica/instrumentação , Células Eucarióticas/ultraestrutura , Substâncias Macromoleculares/ultraestrutura , Modelos Moleculares , Ribossomos/ultraestrutura , Software
5.
Bioessays ; 46(5): e2300122, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38514402

RESUMO

Fluorescence microscopy is a powerful tool used in scientific and medical research, but it is inextricably linked to phototoxicity. Neglecting phototoxicity can lead to erroneous or inconclusive results. Recently, several reports have addressed this issue, but it is still underestimated by many researchers, even though it can lead to cell death. Phototoxicity can be reduced by appropriate microscopic techniques and carefully designed experiments. This review focuses on recent strategies to reduce phototoxicity in microscopic imaging of living cells and tissues. We describe digital image processing and new hardware solutions. We point out new modifications of microscopy methods and hope that this review will interest microscopy hardware engineers. Our aim is to underscore the challenges and potential solutions integral to the design of microscopy systems. Simultaneously, we intend to engage biologists, offering insight into the latest technological advancements in imaging that can enhance their understanding and practice.


Assuntos
Microscopia de Fluorescência , Humanos , Microscopia de Fluorescência/métodos , Animais , Processamento de Imagem Assistida por Computador/métodos
6.
Bioessays ; 46(2): e2300114, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38058114

RESUMO

Bioimage analysis plays a critical role in extracting information from biological images, enabling deeper insights into cellular structures and processes. The integration of machine learning and deep learning techniques has revolutionized the field, enabling the automated, reproducible, and accurate analysis of biological images. Here, we provide an overview of the history and principles of machine learning and deep learning in the context of bioimage analysis. We discuss the essential steps of the bioimage analysis workflow, emphasizing how machine learning and deep learning have improved preprocessing, segmentation, feature extraction, object tracking, and classification. We provide examples that showcase the application of machine learning and deep learning in bioimage analysis. We examine user-friendly software and tools that enable biologists to leverage these techniques without extensive computational expertise. This review is a resource for researchers seeking to incorporate machine learning and deep learning in their bioimage analysis workflows and enhance their research in this rapidly evolving field.


Assuntos
Aprendizado Profundo , Processamento de Imagem Assistida por Computador/métodos , Microscopia de Fluorescência/métodos , Software , Aprendizado de Máquina
7.
Methods ; 224: 63-70, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38367653

RESUMO

Urinalysis is a useful test as an indicator of health or disease and as such, is a part of routine health screening. Urinalysis can be undertaken in many ways, one of which is reagent strips used in the general evaluation of health and to aid in the diagnosis and monitoring of kidney disease. To be effective, the test must be performed properly, and the results interpreted correctly. However, different light conditions and colour perception can vary between users leading to ambiguous readings. This has led to camera devices being used to capture and generate the estimated biomarker concentrations, but image colour can be affected by variations in illumination and inbuilt image processing. Therefore, a new portable device with embedded image processing techniques is presented in this study to provide quantitative measurements that are invariant to changes in illumination. The device includes a novel calibration process and uses the ratio of RGB values to compensate for variations in illumination across an image and improve the accuracy of quantitative measurements. Results show that the proposed calibration method gives consistent homogeneous illumination across the whole image. Comparisons against other existing methods and clinical results show good performance with a correlation to the clinical values. The proposed device can be used for point-of-care testing to provide reliable results consistent with clinical values.


Assuntos
Sistemas Automatizados de Assistência Junto ao Leito , Fitas Reagentes , Urinálise/métodos , Processamento de Imagem Assistida por Computador
8.
Proc Natl Acad Sci U S A ; 119(14): e2122937119, 2022 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-35344419

RESUMO

The bright-field (BF) optical microscope is a traditional bioimaging tool that has been recently tested for depth discrimination during evaluation of specimen morphology; however, existing approaches require dedicated instrumentation or extensive computer modeling. We report a direct method for three-dimensional (3D) imaging in BF microscopy, applicable to label-free samples, where we use Köhler illumination in the coherent regime and conventional digital image processing filters to achieve optical sectioning. By visualizing fungal, animal tissue, and plant samples and comparing with light-sheet fluorescence microscopy imaging, we demonstrate the accuracy and applicability of the method, showing how the standard microscope is an effective 3D imaging device.


Assuntos
Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Animais , Simulação por Computador , Técnicas Histológicas , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Microscopia de Fluorescência/métodos
9.
Nano Lett ; 24(8): 2465-2472, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38349857

RESUMO

The rich morphology of 2D materials grown through chemical vapor deposition (CVD), is a distinctive feature. However, understanding the complex growth of 2D crystals under practical CVD conditions remains a challenge due to various intertwined factors. Real-time monitoring is crucial to providing essential data and enabling the use of advanced tools like machine learning for unraveling these complexities. In this study, we present a custom-built miniaturized CVD system capable of observing and recording 2D MoS2 crystal growth in real time. Image processing converts the real-time footage into digital data, and machine learning algorithms (ML) unveil the significant factors influencing growth. The machine learning model successfully predicts CVD growth parameters for synthesizing ultralarge monolayer MoS2 crystals. It also demonstrates the potential to reverse engineer CVD growth parameters by analyzing the as-grown 2D crystal morphology. This interdisciplinary approach can be integrated to enhance our understanding of controlled 2D crystal synthesis through CVD.

10.
J Struct Biol ; 216(1): 108058, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38163450

RESUMO

In single-particle cryo-electron microscopy (cryo-EM), efficient determination of orientation parameters for particle images poses a significant challenge yet is crucial for reconstructing 3D structures. This task is complicated by the high noise levels in the datasets, which often include outliers, necessitating several time-consuming 2D clean-up processes. Recently, solutions based on deep learning have emerged, offering a more streamlined approach to the traditionally laborious task of orientation estimation. These solutions employ amortized inference, eliminating the need to estimate parameters individually for each image. However, these methods frequently overlook the presence of outliers and may not adequately concentrate on the components used within the network. This paper introduces a novel method using a 10-dimensional feature vector for orientation representation, extracting orientations as unit quaternions with an accompanying uncertainty metric. Furthermore, we propose a unique loss function that considers the pairwise distances between orientations, thereby enhancing the accuracy of our method. Finally, we also comprehensively evaluate the design choices in constructing the encoder network, a topic that has not received sufficient attention in the literature. Our numerical analysis demonstrates that our methodology effectively recovers orientations from 2D cryo-EM images in an end-to-end manner. Notably, the inclusion of uncertainty quantification allows for direct clean-up of the dataset at the 3D level. Lastly, we package our proposed methods into a user-friendly software suite named cryo-forum, designed for easy access by developers.


Assuntos
Processamento de Imagem Assistida por Computador , Software , Microscopia Crioeletrônica/métodos , Incerteza , Processamento de Imagem Assistida por Computador/métodos , Imagem Individual de Molécula
11.
J Biol Chem ; 299(6): 104708, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37061004

RESUMO

Physiologic Ca2+ entry via the Mitochondrial Calcium Uniporter (MCU) participates in energetic adaption to workload but may also contribute to cell death during ischemia/reperfusion (I/R) injury. The MCU has been identified as the primary mode of Ca2+ import into mitochondria. Several groups have tested the hypothesis that Ca2+ import via MCU is detrimental during I/R injury using genetically-engineered mouse models, yet the results from these studies are inconclusive. Furthermore, mitochondria exhibit unstable or oscillatory membrane potentials (ΔΨm) when subjected to stress, such as during I/R, but it is unclear if the primary trigger is an excess influx of mitochondrial Ca2+ (mCa2+), reactive oxygen species (ROS) accumulation, or other factors. Here, we critically examine whether MCU-mediated mitochondrial Ca2+ uptake during I/R is involved in ΔΨm instability, or sustained mitochondrial depolarization, during reperfusion by acutely knocking out MCU in neonatal mouse ventricular myocyte (NMVM) monolayers subjected to simulated I/R. Unexpectedly, we find that MCU knockout does not significantly alter mCa2+ import during I/R, nor does it affect ΔΨm recovery during reperfusion. In contrast, blocking the mitochondrial sodium-calcium exchanger (mNCE) suppressed the mCa2+ increase during Ischemia but did not affect ΔΨm recovery or the frequency of ΔΨm oscillations during reperfusion, indicating that mitochondrial ΔΨm instability on reperfusion is not triggered by mCa2+. Interestingly, inhibition of mitochondrial electron transport or supplementation with antioxidants stabilized I/R-induced ΔΨm oscillations. The findings are consistent with mCa2+ overload being mediated by reverse-mode mNCE activity and supporting ROS-induced ROS release as the primary trigger of ΔΨm instability during reperfusion injury.


Assuntos
Mitocôndrias Cardíacas , Traumatismo por Reperfusão , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Potencial da Membrana Mitocondrial , Mitocôndrias Cardíacas/metabolismo , Isquemia/metabolismo , Traumatismo por Reperfusão/metabolismo , Reperfusão , Cálcio/metabolismo
12.
Neuroimage ; 297: 120685, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38914212

RESUMO

Research into magnetic resonance imaging (MRI)-visible perivascular spaces (PVS) has recently increased, as results from studies in different diseases and populations are cementing their association with sleep, disease phenotypes, and overall health indicators. With the establishment of worldwide consortia and the availability of large databases, computational methods that allow to automatically process all this wealth of information are becoming increasingly relevant. Several computational approaches have been proposed to assess PVS from MRI, and efforts have been made to summarise and appraise the most widely applied ones. We systematically reviewed and meta-analysed all publications available up to September 2023 describing the development, improvement, or application of computational PVS quantification methods from MRI. We analysed 67 approaches and 60 applications of their implementation, from 112 publications. The two most widely applied were the use of a morphological filter to enhance PVS-like structures, with Frangi being the choice preferred by most, and the use of a U-Net configuration with or without residual connections. Older adults or population studies comprising adults from 18 years old onwards were, overall, more frequent than studies using clinical samples. PVS were mainly assessed from T2-weighted MRI acquired in 1.5T and/or 3T scanners, although combinations using it with T1-weighted and FLAIR images were also abundant. Common associations researched included age, sex, hypertension, diabetes, white matter hyperintensities, sleep and cognition, with occupation-related, ethnicity, and genetic/hereditable traits being also explored. Despite promising improvements to overcome barriers such as noise and differentiation from other confounds, a need for joined efforts for a wider testing and increasing availability of the most promising methods is now paramount.

13.
Development ; 148(18)2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34097729

RESUMO

Proper organ development often requires nuclei to move to a specific position within the cell. To determine how nuclear positioning affects left-right (LR) development in the Drosophila anterior midgut (AMG), we developed a surface-modeling method to measure and describe nuclear behavior at stages 13-14, captured in three-dimensional time-lapse movies. We describe the distinctive positioning and a novel collective nuclear behavior by which nuclei align LR symmetrically along the anterior-posterior axis in the visceral muscles that overlie the midgut and are responsible for the LR-asymmetric development of this organ. Wnt4 signaling is crucial for the collective behavior and proper positioning of the nuclei, as are myosin II and the LINC complex, without which the nuclei fail to align LR symmetrically. The LR-symmetric positioning of the nuclei is important for the subsequent LR-asymmetric development of the AMG. We propose that the bilaterally symmetrical positioning of these nuclei may be mechanically coupled with subsequent LR-asymmetric morphogenesis.


Assuntos
Padronização Corporal/fisiologia , Núcleo Celular/fisiologia , Sistema Digestório/fisiopatologia , Drosophila/fisiologia , Morfogênese/fisiologia , Animais , Núcleo Celular/metabolismo , Sistema Digestório/metabolismo , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Músculos/metabolismo , Músculos/fisiologia , Miosina Tipo II/metabolismo , Transdução de Sinais/fisiologia
14.
BMC Plant Biol ; 24(1): 13, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38163882

RESUMO

The ability of a data fusion system composed of a computer vision system (CVS) and an electronic nose (e-nose) was evaluated to predict key physiochemical attributes and distinguish red-fleshed kiwifruit produced in three distinct regions in northern Iran. Color and morphological features from whole and middle-cut kiwifruits, along with the maximum responses of the 13 metal oxide semiconductor (MOS) sensors of an e-nose system, were used as inputs to the data fusion system. Principal component analysis (PCA) revealed that the first two principal components (PCs) extracted from the e-nose features could effectively differentiate kiwifruit samples from different regions. The PCA-SVM algorithm achieved a 93.33% classification rate for kiwifruits from three regions based on data from individual e-nose and CVS. Data fusion increased the classification rate of the SVM model to 100% and improved the performance of Support Vector Regression (SVR) for predicting physiochemical indices of kiwifruits compared to individual systems. The data fusion-based PCA-SVR models achieved validation R2 values ranging from 90.17% for the Brix-Acid Ratio (BAR) to 98.57% for pH prediction. These results demonstrate the high potential of fusing artificial visual and olfactory systems for quality monitoring and identifying the geographical growing regions of kiwifruits.


Assuntos
Algoritmos , Nariz Eletrônico , Inteligência Artificial , Irã (Geográfico)
15.
Small ; 20(27): e2307306, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38312110

RESUMO

Intrinsically magnetic cells naturally occur within organisms and are believed to be linked to iron metabolism and certain cellular functions while the functional significance of this magnetism is largely unexplored. To better understand this property, an approach named Optical Tracking-based Magnetic Sensor (OTMS) has been developed. This multi-target tracking system is designed to measure the magnetic moment of individual cells. The OTMS generates a tunable magnetic field and induces movement in magnetic cells that are subsequently analyzed through a learning-based tracking-by-detection system. The magnetic moment of numerous cells can be calculated simultaneously, thereby providing a quantitative tool to assess cellular magnetic properties within populations. Upon deploying the OTMS, a stable population of magnetic cells in human peripheral monocytes is discovered. Further application in the analysis of clinical blood samples reveals an intriguing pattern: the proportion of magnetic monocytes differs significantly between systemic lupus erythematosus (SLE) patients and healthy volunteers. This variation is positively correlated with disease activity, a trend not observed in patients with rheumatoid arthritis (RA). The study, therefore, presents a new frontier in the investigation of the magnetic characteristics of naturally occurring magnetic cells, opening the door to potential diagnostic and therapeutic applications that leverage cellular magnetism.


Assuntos
Monócitos , Humanos , Monócitos/citologia , Monócitos/metabolismo , Lúpus Eritematoso Sistêmico , Magnetismo , Artrite Reumatoide/patologia , Rastreamento de Células/métodos
16.
Small ; : e2401238, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602230

RESUMO

Multifunctional devices integrated with electrochromic and supercapacitance properties are fascinating because of their extensive usage in modern electronic applications. In this work, vanadium-doped cobalt chloride carbonate hydroxide hydrate nanostructures (V-C3H NSs) are successfully synthesized and show unique electrochromic and supercapacitor properties. The V-C3H NSs material exhibits a high specific capacitance of 1219.9 F g-1 at 1 mV s-1 with a capacitance retention of 100% over 30 000 CV cycles. The electrochromic performance of the V-C3H NSs material is confirmed through in situ spectroelectrochemical measurements, where the switching time, coloration efficiency (CE), and optical modulation (∆T) are found to be 15.7 and 18.8 s, 65.85 cm2 C-1 and 69%, respectively. A coupled multilayer artificial neural network (ANN) model is framed to predict potential and current from red (R), green (G), and blue (B) color values. The optimized V-C3H NSs are used as the active materials in the fabrication of flexible/wearable electrochromic micro-supercapacitor devices (FEMSDs) through a cost-effective mask-assisted vacuum filtration method. The fabricated FEMSD exhibits an areal capacitance of 47.15 mF cm-2 at 1 mV s-1 and offers a maximum areal energy and power density of 104.78 Wh cm-2 and 0.04 mW cm-2, respectively. This material's interesting energy storage and electrochromic properties are promising in multifunctional electrochromic energy storage applications.

17.
Biol Reprod ; 110(6): 1086-1099, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38537569

RESUMO

Cancer survival rates in prepubertal girls and young women have risen in recent decades due to increasingly efficient treatments. However, many such treatments are gonadotoxic, causing premature ovarian insufficiency, loss of fertility, and ovarian endocrine function. Implantation of donor ovarian tissue encapsulated in immune-isolating capsules is a promising method to restore physiological endocrine function without immunosuppression or risk of reintroducing cancer cells harbored by the tissue. The success of this approach is largely determined by follicle density in the implanted ovarian tissue, which is analyzed manually from histologic sections and necessitates specialized, time-consuming labor. To address this limitation, we developed a fully automated method to quantify follicle density that does not require additional coding. We first analyzed ovarian tissue from 12 human donors between 16 and 37 years old using semi-automated image processing with manual follicle annotation and then trained artificial intelligence program based on follicle identification and object classification. One operator manually analyzed 102 whole slide images from serial histologic sections. Of those, 77 images were assessed by a second manual operator, followed with an automated method utilizing artificial intelligence. Of the 1181 follicles the control operator counted, the comparison operator counted 1178, and the artificial intelligence counted 927 follicles with 80% of those being correctly identified as follicles. The three-stage artificial intelligence pipeline finished 33% faster than manual annotation. Collectively, this report supports the use of artificial intelligence and automation to select tissue donors and grafts with the greatest follicle density to ensure graft longevity for premature ovarian insufficiency treatment.


Assuntos
Inteligência Artificial , Processamento de Imagem Assistida por Computador , Folículo Ovariano , Humanos , Feminino , Adulto , Adolescente , Processamento de Imagem Assistida por Computador/métodos , Adulto Jovem , Software , Ovário/transplante
18.
Magn Reson Med ; 91(1): 388-397, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37676923

RESUMO

PURPOSE: MR-guided cardiac catheterization procedures currently use passive tracking approaches to follow a gadolinium-filled catheter balloon during catheter navigation. This requires frequent manual tracking and repositioning of the imaging slice during navigation. In this study, a novel framework for automatic real-time catheter tracking during MR-guided cardiac catheterization is presented. METHODS: The proposed framework includes two imaging modes (Calibration and Runtime). The sequence starts in Calibration mode, in which the 3D catheter coordinates are determined using a stack of 10-20 contiguous saturated slices combined with real-time image processing. The sequence then automatically switches to Runtime mode, where three contiguous slices (acquired with partial saturation), initially centered on the catheter balloon using the Calibration feedback, are acquired continuously. The 3D catheter balloon coordinates are estimated in real time from each Runtime slice stack using image processing. Each Runtime stack is repositioned to maintain the catheter balloon in the central slice based on the prior Runtime feedback. The sequence switches back to Calibration mode if the catheter is not detected. This framework was evaluated in a heart phantom and 3 patients undergoing MR-guided cardiac catheterization. Catheter detection accuracy and rate of catheter visibility were evaluated. RESULTS: The automatic detection accuracy for the catheter balloon during the Calibration/Runtime mode was 100%/95% in phantom and 100%/97 ± 3% in patients. During Runtime, the catheter was visible in 82% and 98 ± 2% of the real-time measurements in the phantom and patients, respectively. CONCLUSION: The proposed framework enabled real-time continuous automatic tracking of a gadolinium-filled catheter balloon during MR-guided cardiac catheterization.


Assuntos
Cateterismo Cardíaco , Gadolínio , Humanos , Cateterismo Cardíaco/métodos , Catéteres , Imagens de Fantasmas , Coração
19.
J Anat ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760955

RESUMO

X-ray Computed Tomography (CT) images are widely used in various fields of natural, physical, and biological sciences. 3D reconstruction of the images involves segmentation of the structures of interest. Manual segmentation has been widely used in the field of biological sciences for complex structures composed of several sub-parts and can be a time-consuming process. Many tools have been developed to automate the segmentation process, all with various limitations and advantages, however, multipart segmentation remains a largely manual process. The aim of this study was to develop an open-access and user-friendly tool for the automatic segmentation of calcified tissues, specifically focusing on craniofacial bones. Here we describe BounTI, a novel segmentation algorithm which preserves boundaries between separate segments through iterative thresholding. This study outlines the working principles behind this algorithm, investigates the effect of several input parameters on its outcome, and then tests its versatility on CT images of the craniofacial system from different species (e.g. a snake, a lizard, an amphibian, a mouse and a human skull) with various scan qualities. The case studies demonstrate that this algorithm can be effectively used to segment the craniofacial system of a range of species automatically. High-resolution microCT images resulted in more accurate boundary-preserved segmentation, nonetheless significantly lower-quality clinical images could still be segmented using the proposed algorithm. Methods for manual intervention are included in this tool when the scan quality is insufficient to achieve the desired segmentation results. While the focus here was on the craniofacial system, BounTI can be used to automatically segment any hard tissue. The tool presented here is available as an Avizo/Amira add-on, a stand-alone Windows executable, and a Python library. We believe this accessible and user-friendly segmentation tool can benefit the wider anatomical community.

20.
Hum Reprod ; 39(6): 1197-1207, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38600621

RESUMO

STUDY QUESTION: Can generative artificial intelligence (AI) models produce high-fidelity images of human blastocysts? SUMMARY ANSWER: Generative AI models exhibit the capability to generate high-fidelity human blastocyst images, thereby providing substantial training datasets crucial for the development of robust AI models. WHAT IS KNOWN ALREADY: The integration of AI into IVF procedures holds the potential to enhance objectivity and automate embryo selection for transfer. However, the effectiveness of AI is limited by data scarcity and ethical concerns related to patient data privacy. Generative adversarial networks (GAN) have emerged as a promising approach to alleviate data limitations by generating synthetic data that closely approximate real images. STUDY DESIGN, SIZE, DURATION: Blastocyst images were included as training data from a public dataset of time-lapse microscopy (TLM) videos (n = 136). A style-based GAN was fine-tuned as the generative model. PARTICIPANTS/MATERIALS, SETTING, METHODS: We curated a total of 972 blastocyst images as training data, where frames were captured within the time window of 110-120 h post-insemination at 1-h intervals from TLM videos. We configured the style-based GAN model with data augmentation (AUG) and pretrained weights (Pretrained-T: with translation equivariance; Pretrained-R: with translation and rotation equivariance) to compare their optimization on image synthesis. We then applied quantitative metrics including Fréchet Inception Distance (FID) and Kernel Inception Distance (KID) to assess the quality and fidelity of the generated images. Subsequently, we evaluated qualitative performance by measuring the intelligence behavior of the model through the visual Turing test. To this end, 60 individuals with diverse backgrounds and expertise in clinical embryology and IVF evaluated the quality of synthetic embryo images. MAIN RESULTS AND THE ROLE OF CHANCE: During the training process, we observed consistent improvement of image quality that was measured by FID and KID scores. Pretrained and AUG + Pretrained initiated with remarkably lower FID and KID values compared to both Baseline and AUG + Baseline models. Following 5000 training iterations, the AUG + Pretrained-R model showed the highest performance of the evaluated five configurations with FID and KID scores of 15.2 and 0.004, respectively. Subsequently, we carried out the visual Turing test, such that IVF embryologists, IVF laboratory technicians, and non-experts evaluated the synthetic blastocyst-stage embryo images and obtained similar performance in specificity with marginal differences in accuracy and sensitivity. LIMITATIONS, REASONS FOR CAUTION: In this study, we primarily focused the training data on blastocyst images as IVF embryos are primarily assessed in blastocyst stage. However, generation of an array of images in different preimplantation stages offers further insights into the development of preimplantation embryos and IVF success. In addition, we resized training images to a resolution of 256 × 256 pixels to moderate the computational costs of training the style-based GAN models. Further research is needed to involve a more extensive and diverse dataset from the formation of the zygote to the blastocyst stage, e.g. video generation, and the use of improved image resolution to facilitate the development of comprehensive AI algorithms and to produce higher-quality images. WIDER IMPLICATIONS OF THE FINDINGS: Generative AI models hold promising potential in generating high-fidelity human blastocyst images, which allows the development of robust AI models as it can provide sufficient training datasets while safeguarding patient data privacy. Additionally, this may help to produce sufficient embryo imaging training data with different (rare) abnormal features, such as embryonic arrest, tripolar cell division to avoid class imbalances and reach to even datasets. Thus, generative models may offer a compelling opportunity to transform embryo selection procedures and substantially enhance IVF outcomes. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by a Horizon 2020 innovation grant (ERIN, grant no. EU952516) and a Horizon Europe grant (NESTOR, grant no. 101120075) of the European Commission to A.S. and M.Z.E., the Estonian Research Council (grant no. PRG1076) to A.S., and the EVA (Erfelijkheid Voortplanting & Aanleg) specialty program (grant no. KP111513) of Maastricht University Medical Centre (MUMC+) to M.Z.E. TRIAL REGISTRATION NUMBER: Not applicable.


Assuntos
Inteligência Artificial , Blastocisto , Humanos , Imagem com Lapso de Tempo/métodos , Processamento de Imagem Assistida por Computador/métodos , Fertilização in vitro/métodos , Feminino
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