在临床实践中,由于较短的获取时间和较低的存储成本,通常使用了平面分辨率低的各向异性体积医学图像。然而,粗分辨率可能导致医生或计算机辅助诊断算法的医学诊断困难。基于深度学习的体积超分辨率(SR)方法是改善分辨率的可行方法,其核心是卷积神经网络(CNN)。尽管进展最近,但这些方法受到卷积运算符的固有属性的限制,卷积运算符忽略内容相关性,无法有效地对远程依赖性进行建模。此外,大多数现有方法都使用伪配合的体积进行训练和评估,其中伪低分辨率(LR)体积是通过简单的高分辨率(HR)对应物的简单降解而产生的。但是,伪和现实LR之间的域间隙导致这些方法在实践中的性能不佳。在本文中,我们构建了第一个公共实用数据集RPLHR-CT作为体积SR的基准,并通过重新实现四种基于CNN的最先进的方法来提供基线结果。考虑到CNN的固有缺点,我们还提出了基于注意力机制的变压器体积超分辨率网络(TVSRN),完全与卷积分配。这是首次将纯变压器用于CT体积SR的研究。实验结果表明,TVSRN在PSNR和SSIM上的所有基准都显着胜过。此外,TVSRN方法在图像质量,参数数量和运行时间之间取得了更好的权衡。数据和代码可在https://github.com/smilenaxx/rplhr-ct上找到。
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通过纵向病变跟踪评估病变进展和治疗反应在临床实践中起着至关重要的作用。当手动进行病变匹配时,该任务的自动化方法是由劳动力成本和时间消耗的促进的。以前的方法通常缺乏本地和全球信息的集成。在这项工作中,我们提出了一种基于变压器的方法,称为变压器病变跟踪器(TLT)。具体而言,我们设计了一个基于注意力的变压器(CAT),以捕获和组合全球和本地信息以增强特征提取。我们还开发了一个基于注册的解剖注意模块(RAAM),以向CAT介绍解剖信息,以便它可以专注于有用的特征知识。提出了一种稀疏选择策略(SSS),用于选择特征和减少变压器训练中的内存足迹。此外,我们使用全球回归来进一步提高模型性能。我们在公共数据集上进行实验,以显示我们方法的优势,并发现我们的模型性能使欧几里得中心的平均误差至少提高了至少14.3%(6mm vs. 7mm),而不是先进的ART(SOTA) )。代码可在https://github.com/tangwen920812/tlt上找到。
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对于放射科医生和深度学习算法而言,MRI的早期前列腺癌检测和分期是极具挑战性的任务,但是向大型和多样化数据集学习的潜力仍然是提高其内部和整个诊所的概括能力的有希望的途径。为了对原型阶段算法进行此项启用,其中大多数现有研究仍然存在,在本文中,我们引入了一个灵活的联合学习框架,用于跨站点培训,验证和评估深前列腺癌检测算法。我们的方法利用了模型体系结构和数据的抽象表示,该表示允许使用NVFlare联合学习框架对未打磨的原型深度学习模型进行培训。我们的结果表明,使用专门的神经网络模型以及在加利福尼亚大学两家研究医院收集的专门神经网络模型以及不同的前列腺活检数据的前列腺癌检测和分类精度的提高,这证明了我们方法在适应不同数据集并改善MR-Biomarker发现的方法方面的功效。我们开源的FLTOOLS系统可以很容易地适应其他深度学习项目进行医学成像。
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\ textit {objection:}基于gadolinium的对比剂(GBCA)已被广泛用于更好地可视化脑磁共振成像中的疾病(MRI)。然而,大脑和身体内部的gadolin量引起了人们对使用GBCA的安全问题。因此,在提供类似的对比度信息的同时,可以减少甚至消除GBCA暴露的新方法的发展将在临床上具有重大用途。 \ textit {方法:}在这项工作中,我们提出了一种基于深度学习的方法,用于对脑肿瘤患者的对比增强T1合成。 3D高分辨率完全卷积网络(FCN)通过处理和聚合并行的多尺度信息保持高分辨率信息,旨在将前对比度MRI序列映射到对比度增强的MRI序列。具体而言,将三个前对比的MRI序列T1,T2和表观扩散系数图(ADC)用作输入,而对比后T1序列则被用作目标输出。为了减轻正常组织与肿瘤区域之间的数据不平衡问题,我们引入了局部损失,以改善肿瘤区域的贡献,从而可以更好地增强对肿瘤的增强结果。 \ textIt {结果:}进行了广泛的定量和视觉评估,我们提出的模型在大脑中达到28.24db的PSNR,在肿瘤区域达到21.2db。 \ textit {结论和意义:}我们的结果表明,用深度学习产生的合成对比图像代替GBCA的潜力。代码可在\ url {https://github.com/chenchao666/contrast-enhanced-mri-synthesis中获得
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我们概述了新兴机会和挑战,以提高AI对科学发现的效用。AI为行业的独特目标与AI科学的目标创造了识别模式中的识别模式与来自数据的发现模式之间的紧张。如果我们解决了与域驱动的科学模型和数据驱动的AI学习机之间的“弥补差距”相关的根本挑战,那么我们预计这些AI模型可以改变假说发电,科学发现和科学过程本身。
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Making histopathology image classifiers robust to a wide range of real-world variability is a challenging task. Here, we describe a candidate deep learning solution for the Mitosis Domain Generalization Challenge 2022 (MIDOG) to address the problem of generalization for mitosis detection in images of hematoxylin-eosin-stained histology slides under high variability (scanner, tissue type and species variability). Our approach consists in training a rotation-invariant deep learning model using aggressive data augmentation with a training set enriched with hard negative examples and automatically selected negative examples from the unlabeled part of the challenge dataset. To optimize the performance of our models, we investigated a hard negative mining regime search procedure that lead us to train our best model using a subset of image patches representing 19.6% of our training partition of the challenge dataset. Our candidate model ensemble achieved a F1-score of .697 on the final test set after automated evaluation on the challenge platform, achieving the third best overall score in the MIDOG 2022 Challenge.
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Supervised Question Answering systems (QA systems) rely on domain-specific human-labeled data for training. Unsupervised QA systems generate their own question-answer training pairs, typically using secondary knowledge sources to achieve this outcome. Our approach (called PIE-QG) uses Open Information Extraction (OpenIE) to generate synthetic training questions from paraphrased passages and uses the question-answer pairs as training data for a language model for a state-of-the-art QA system based on BERT. Triples in the form of <subject, predicate, object> are extracted from each passage, and questions are formed with subjects (or objects) and predicates while objects (or subjects) are considered as answers. Experimenting on five extractive QA datasets demonstrates that our technique achieves on-par performance with existing state-of-the-art QA systems with the benefit of being trained on an order of magnitude fewer documents and without any recourse to external reference data sources.
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While the capabilities of autonomous systems have been steadily improving in recent years, these systems still struggle to rapidly explore previously unknown environments without the aid of GPS-assisted navigation. The DARPA Subterranean (SubT) Challenge aimed to fast track the development of autonomous exploration systems by evaluating their performance in real-world underground search-and-rescue scenarios. Subterranean environments present a plethora of challenges for robotic systems, such as limited communications, complex topology, visually-degraded sensing, and harsh terrain. The presented solution enables long-term autonomy with minimal human supervision by combining a powerful and independent single-agent autonomy stack, with higher level mission management operating over a flexible mesh network. The autonomy suite deployed on quadruped and wheeled robots was fully independent, freeing the human supervision to loosely supervise the mission and make high-impact strategic decisions. We also discuss lessons learned from fielding our system at the SubT Final Event, relating to vehicle versatility, system adaptability, and re-configurable communications.
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While the brain connectivity network can inform the understanding and diagnosis of developmental dyslexia, its cause-effect relationships have not yet enough been examined. Employing electroencephalography signals and band-limited white noise stimulus at 4.8 Hz (prosodic-syllabic frequency), we measure the phase Granger causalities among channels to identify differences between dyslexic learners and controls, thereby proposing a method to calculate directional connectivity. As causal relationships run in both directions, we explore three scenarios, namely channels' activity as sources, as sinks, and in total. Our proposed method can be used for both classification and exploratory analysis. In all scenarios, we find confirmation of the established right-lateralized Theta sampling network anomaly, in line with the temporal sampling framework's assumption of oscillatory differences in the Theta and Gamma bands. Further, we show that this anomaly primarily occurs in the causal relationships of channels acting as sinks, where it is significantly more pronounced than when only total activity is observed. In the sink scenario, our classifier obtains 0.84 and 0.88 accuracy and 0.87 and 0.93 AUC for the Theta and Gamma bands, respectively.
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Vocal Bursts -- short, non-speech vocalizations that convey emotions, such as laughter, cries, sighs, moans, and groans -- are an often-overlooked aspect of speech emotion recognition, but an important aspect of human vocal communication. One barrier to study of these interesting vocalizations is a lack of large datasets. I am pleased to introduce the EmoGator dataset, which consists of 32,040 samples from 365 speakers, 16.91 hours of audio; each sample classified into one of 30 distinct emotion categories by the speaker. Several different approaches to construct classifiers to identify emotion categories will be discussed, and directions for future research will be suggested. Data set is available for download from https://github.com/fredbuhl/EmoGator.
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