深度学习已在许多神经影像应用中有效。但是，在许多情况下，捕获与小血管疾病有关的信息的成像序列的数量不足以支持数据驱动的技术。此外，基于队列的研究可能并不总是具有用于准确病变检测的最佳或必需成像序列。因此，有必要确定哪些成像序列对于准确检测至关重要。在这项研究中，我们旨在找到磁共振成像（MRI）序列的最佳组合，以深入基于学习的肿瘤周围空间（EPV）。为此，我们实施了一个有效的轻巧U-NET，适用于EPVS检测，并全面研究了来自易感加权成像（SWI），流体侵入的反转恢复（FLAIR），T1加权（T1W）和T2的不同信息组合 - 加权（T2W）MRI序列。我们得出的结论是，T2W MRI对于准确的EPV检测最为重要，并且在深神经网络中掺入SWI，FLAIR和T1W MRI可能会使精度的提高无关。

生成的对抗网络（GAN）是在众多领域成功使用的一种强大的深度学习模型。它们属于一个称为生成方法的更广泛的家族，该家族通过从真实示例中学习样本分布来生成新数据。在临床背景下，与传统的生成方法相比，GAN在捕获空间复杂，非线性和潜在微妙的疾病作用方面表现出增强的能力。这篇综述评估了有关gan在各种神经系统疾病的成像研究中的应用的现有文献，包括阿尔茨海默氏病，脑肿瘤，脑老化和多发性硬化症。我们为每个应用程序提供了各种GAN方法的直观解释，并进一步讨论了在神经影像学中利用gans的主要挑战，开放问题以及有希望的未来方向。我们旨在通过强调如何利用gan来支持临床决策，并有助于更好地理解脑部疾病的结构和功能模式，从而弥合先进的深度学习方法和神经病学研究之间的差距。

深度学习（DL）模型为各种医学成像基准挑战提供了最先进的性能，包括脑肿瘤细分（BRATS）挑战。然而，局灶性病理多隔室分割（例如，肿瘤和病变子区）的任务特别具有挑战性，并且潜在的错误阻碍DL模型转化为临床工作流程。量化不确定形式的DL模型预测的可靠性，可以实现最不确定的地区的临床审查，从而建立信任并铺平临床翻译。最近，已经引入了许多不确定性估计方法，用于DL医学图像分割任务。开发指标评估和比较不确定性措施的表现将有助于最终用户制定更明智的决策。在本研究中，我们探索并评估在Brats 2019-2020任务期间开发的公制，以对不确定量化量化（Qu-Brats），并旨在评估和排列脑肿瘤多隔室分割的不确定性估计。该公制（1）奖励不确定性估计，对正确断言产生高置信度，以及在不正确的断言处分配低置信水平的估计数，（2）惩罚导致更高百分比的无关正确断言百分比的不确定性措施。我们进一步基准测试由14个独立参与的Qu-Brats 2020的分割不确定性，所有这些都参与了主要的Brats细分任务。总体而言，我们的研究结果证实了不确定性估计提供了分割算法的重要性和互补价值，因此突出了医学图像分析中不确定性量化的需求。我们的评估代码在HTTPS://github.com/ragmeh11/qu-brats公开提供。

纵向脑磁共振成像（MRI）含有病理扫描的登记是由于组织外观变化而挑战，仍然是未解决的问题。本文介绍了第一脑肿瘤序列登记（Brats-Reg）挑战，重点是估计诊断患有脑弥漫性胶质瘤的同一患者的术前和后续扫描之间的对应关系。 Brats-Reg挑战打算建立可变形登记算法的公共基准环境。关联的数据集包括根据公共解剖模板，为每个扫描的大小和分辨率策划的DE识别的多机构多参数MRI（MPMRI）数据。临床专家在扫描内产生了广泛的标志标记点，描述了跨时域的不同解剖位置。培训数据以及这些地面真相注释将被释放给参与者来设计和开发他们的注册算法，而组织者将扣留验证和测试数据的注释，并用于评估参与者的集装箱化算法。每个所提交的算法都将使用几个度量来定量评估，例如中位绝对误差（MAE），鲁棒性和雅可比的决定因素。

域移位，训练与测试数据特征之间的不匹配，导致多源成像方案中的预测性能显着降低。在医学成像中，不同网站的人口，扫描仪和采集协议的异质性提出了一个重要的领域移位挑战，并限制了机器学习模型的广泛临床采用。统一方法旨在学习数据不变的表示这些差异是解决域移位的普遍工具，但它们通常会导致预测精度的劣化。本文对问题进行了不同的视角：我们拥抱这种不和谐的数据并设计一个简单但有效的解决域名框架。根据我们的理论参数，关键的想法是在源数据上构建备用分类器并将此模型调整为新数据。可以为站点内域适应微调分类器。我们还可以在目标数据上处理我们无法访问地面真理标签的情况;我们展示如何使用辅助任务来适应;这些任务雇用协变量，如年龄，性别和种族，这很容易获得，但仍然与主要任务相关联。我们在大规模现实世界3D脑MRI数据集上展示了站点内部域适应和站点间域推广的大量改进，用于分类阿尔茨海默病和精神分裂症。

Given a large graph with few node labels, how can we (a) identify the mixed network-effect of the graph and (b) predict the unknown labels accurately and efficiently? This work proposes Network Effect Analysis (NEA) and UltraProp, which are based on two insights: (a) the network-effect (NE) insight: a graph can exhibit not only one of homophily and heterophily, but also both or none in a label-wise manner, and (b) the neighbor-differentiation (ND) insight: neighbors have different degrees of influence on the target node based on the strength of connections. NEA provides a statistical test to check whether a graph exhibits network-effect or not, and surprisingly discovers the absence of NE in many real-world graphs known to have heterophily. UltraProp solves the node classification problem with notable advantages: (a) Accurate, thanks to the network-effect (NE) and neighbor-differentiation (ND) insights; (b) Explainable, precisely estimating the compatibility matrix; (c) Scalable, being linear with the input size and handling graphs with millions of nodes; and (d) Principled, with closed-form formula and theoretical guarantee. Applied on eight real-world graph datasets, UltraProp outperforms top competitors in terms of accuracy and run time, requiring only stock CPU servers. On a large real-world graph with 1.6M nodes and 22.3M edges, UltraProp achieves more than 9 times speedup (12 minutes vs. 2 hours) compared to most competitors.

High content imaging assays can capture rich phenotypic response data for large sets of compound treatments, aiding in the characterization and discovery of novel drugs. However, extracting representative features from high content images that can capture subtle nuances in phenotypes remains challenging. The lack of high-quality labels makes it difficult to achieve satisfactory results with supervised deep learning. Self-Supervised learning methods, which learn from automatically generated labels has shown great success on natural images, offer an attractive alternative also to microscopy images. However, we find that self-supervised learning techniques underperform on high content imaging assays. One challenge is the undesirable domain shifts present in the data known as batch effects, which may be caused by biological noise or uncontrolled experimental conditions. To this end, we introduce Cross-Domain Consistency Learning (CDCL), a novel approach that is able to learn in the presence of batch effects. CDCL enforces the learning of biological similarities while disregarding undesirable batch-specific signals, which leads to more useful and versatile representations. These features are organised according to their morphological changes and are more useful for downstream tasks - such as distinguishing treatments and mode of action.

While risk-neutral reinforcement learning has shown experimental success in a number of applications, it is well-known to be non-robust with respect to noise and perturbations in the parameters of the system. For this reason, risk-sensitive reinforcement learning algorithms have been studied to introduce robustness and sample efficiency, and lead to better real-life performance. In this work, we introduce new model-free risk-sensitive reinforcement learning algorithms as variations of widely-used Policy Gradient algorithms with similar implementation properties. In particular, we study the effect of exponential criteria on the risk-sensitivity of the policy of a reinforcement learning agent, and develop variants of the Monte Carlo Policy Gradient algorithm and the online (temporal-difference) Actor-Critic algorithm. Analytical results showcase that the use of exponential criteria generalize commonly used ad-hoc regularization approaches. The implementation, performance, and robustness properties of the proposed methods are evaluated in simulated experiments.

Hierarchical learning algorithms that gradually approximate a solution to a data-driven optimization problem are essential to decision-making systems, especially under limitations on time and computational resources. In this study, we introduce a general-purpose hierarchical learning architecture that is based on the progressive partitioning of a possibly multi-resolution data space. The optimal partition is gradually approximated by solving a sequence of optimization sub-problems that yield a sequence of partitions with increasing number of subsets. We show that the solution of each optimization problem can be estimated online using gradient-free stochastic approximation updates. As a consequence, a function approximation problem can be defined within each subset of the partition and solved using the theory of two-timescale stochastic approximation algorithms. This simulates an annealing process and defines a robust and interpretable heuristic method to gradually increase the complexity of the learning architecture in a task-agnostic manner, giving emphasis to regions of the data space that are considered more important according to a predefined criterion. Finally, by imposing a tree structure in the progression of the partitions, we provide a means to incorporate potential multi-resolution structure of the data space into this approach, significantly reducing its complexity, while introducing hierarchical feature extraction properties similar to certain classes of deep learning architectures. Asymptotic convergence analysis and experimental results are provided for clustering, classification, and regression problems.

Being able to forecast the popularity of new garment designs is very important in an industry as fast paced as fashion, both in terms of profitability and reducing the problem of unsold inventory. Here, we attempt to address this task in order to provide informative forecasts to fashion designers within a virtual reality designer application that will allow them to fine tune their creations based on current consumer preferences within an interactive and immersive environment. To achieve this we have to deal with the following central challenges: (1) the proposed method should not hinder the creative process and thus it has to rely only on the garment's visual characteristics, (2) the new garment lacks historical data from which to extrapolate their future popularity and (3) fashion trends in general are highly dynamical. To this end, we develop a computer vision pipeline fine tuned on fashion imagery in order to extract relevant visual features along with the category and attributes of the garment. We propose a hierarchical label sharing (HLS) pipeline for automatically capturing hierarchical relations among fashion categories and attributes. Moreover, we propose MuQAR, a Multimodal Quasi-AutoRegressive neural network that forecasts the popularity of new garments by combining their visual features and categorical features while an autoregressive neural network is modelling the popularity time series of the garment's category and attributes. Both the proposed HLS and MuQAR prove capable of surpassing the current state-of-the-art in key benchmark datasets, DeepFashion for image classification and VISUELLE for new garment sales forecasting.