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。
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Deformable image registration is a key task in medical image analysis. The Brain Tumor Sequence Registration challenge (BraTS-Reg) aims at establishing correspondences between pre-operative and follow-up scans of the same patient diagnosed with an adult brain diffuse high-grade glioma and intends to address the challenging task of registering longitudinal data with major tissue appearance changes. In this work, we proposed a two-stage cascaded network based on the Inception and TransMorph models. The dataset for each patient was comprised of a native pre-contrast (T1), a contrast-enhanced T1-weighted (T1-CE), a T2-weighted (T2), and a Fluid Attenuated Inversion Recovery (FLAIR). The Inception model was used to fuse the 4 image modalities together and extract the most relevant information. Then, a variant of the TransMorph architecture was adapted to generate the displacement fields. The Loss function was composed of a standard image similarity measure, a diffusion regularizer, and an edge-map similarity measure added to overcome intensity dependence and reinforce correct boundary deformation. We observed that the addition of the Inception module substantially increased the performance of the network. Additionally, performing an initial affine registration before training the model showed improved accuracy in the landmark error measurements between pre and post-operative MRIs. We observed that our best model composed of the Inception and TransMorph architectures while using an initially affine registered dataset had the best performance with a median absolute error of 2.91 (initial error = 7.8). We achieved 6th place at the time of model submission in the final testing phase of the BraTS-Reg challenge.
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通常需要对术前和术后大脑图像进行注册,以评估脑神经胶质瘤治疗的有效性。尽管最近基于深度学习的可变形注册方法在健康的大脑图像方面取得了显着的成功,但由于参考图像中缺乏对应关系,它们中的大多数人将无法与病理相处。在本文中,我们提出了一种基于深度学习的可变形登记方法,该方法共同估计缺乏对应关系和双向变形场的区域。前向后的一致性约束用于帮助从两个图像中缺乏对应关系的体素的切除和复发区域的定位。来自Brats-Reg挑战的3D临床数据的结果表明,与传统和深度学习的注册方法相比,我们的方法可以改善图像对齐方式,无论是否具有成本函数掩盖策略。源代码可在https://github.com/cwmok/dirac上获得。
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迄今为止,迄今为止,众所周知,对广泛的互补临床相关任务进行了全面比较了医学图像登记方法。这限制了采用研究进展,以防止竞争方法的公平基准。在过去五年内已经探讨了许多新的学习方法,但优化,建筑或度量战略的问题非常适合仍然是开放的。 Learn2reg涵盖了广泛的解剖学:脑,腹部和胸部,方式:超声波,CT,MRI,群体:患者内部和患者内部和监督水平。我们为3D注册的培训和验证建立了较低的入境障碍,这帮助我们从20多个独特的团队中汇编了65多个单独的方法提交的结果。我们的互补度量集,包括稳健性,准确性,合理性和速度,使得能够独特地位了解当前的医学图像登记现状。进一步分析监督问题的转移性,偏见和重要性,主要是基于深度学习的方法的优越性,并将新的研究方向开放到利用GPU加速的常规优化的混合方法。
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State-of-the-art brain tumor segmentation is based on deep learning models applied to multi-modal MRIs. Currently, these models are trained on images after a preprocessing stage that involves registration, interpolation, brain extraction (BE, also known as skull-stripping) and manual correction by an expert. However, for clinical practice, this last step is tedious and time-consuming and, therefore, not always feasible, resulting in skull-stripping faults that can negatively impact the tumor segmentation quality. Still, the extent of this impact has never been measured for any of the many different BE methods available. In this work, we propose an automatic brain tumor segmentation pipeline and evaluate its performance with multiple BE methods. Our experiments show that the choice of a BE method can compromise up to 15.7% of the tumor segmentation performance. Moreover, we propose training and testing tumor segmentation models on non-skull-stripped images, effectively discarding the BE step from the pipeline. Our results show that this approach leads to a competitive performance at a fraction of the time. We conclude that, in contrast to the current paradigm, training tumor segmentation models on non-skull-stripped images can be the best option when high performance in clinical practice is desired.
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Automatic segmentation is essential for the brain tumor diagnosis, disease prognosis, and follow-up therapy of patients with gliomas. Still, accurate detection of gliomas and their sub-regions in multimodal MRI is very challenging due to the variety of scanners and imaging protocols. Over the last years, the BraTS Challenge has provided a large number of multi-institutional MRI scans as a benchmark for glioma segmentation algorithms. This paper describes our contribution to the BraTS 2022 Continuous Evaluation challenge. We propose a new ensemble of multiple deep learning frameworks namely, DeepSeg, nnU-Net, and DeepSCAN for automatic glioma boundaries detection in pre-operative MRI. It is worth noting that our ensemble models took first place in the final evaluation on the BraTS testing dataset with Dice scores of 0.9294, 0.8788, and 0.8803, and Hausdorf distance of 5.23, 13.54, and 12.05, for the whole tumor, tumor core, and enhancing tumor, respectively. Furthermore, the proposed ensemble method ranked first in the final ranking on another unseen test dataset, namely Sub-Saharan Africa dataset, achieving mean Dice scores of 0.9737, 0.9593, and 0.9022, and HD95 of 2.66, 1.72, 3.32 for the whole tumor, tumor core, and enhancing tumor, respectively. The docker image for the winning submission is publicly available at (https://hub.docker.com/r/razeineldin/camed22).
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在图像登记中,许多努力已经致力于开发流行的标准化互信息标准的替代方案。同时对这些努力,越来越多的作品已经证明了登记准确性的大量收益也可以通过对准图像的结构表示而不是图像本身来实现的。在这条研究路径之后,我们提出了一种基于从诸如梯度矢量流场的结构信息的正则化矢量字段的对准来提出一种新方法,如梯度向量流字段,我们调用\ Texit {Vector Field Mettionity}。我们的方法可以通过将矢量字段相似与基于强度的注册的替换方法相似,以直接的方式与任何现有的登记框架组合。在我们的实验中,我们表明所提出的方法在几个公共图像数据集上使用多样性的成像方式和解剖位置对几个公共图像数据集进行了比较。
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通过磁共振成像(MRI)评估肿瘤负担对于评估胶质母细胞瘤的治疗反应至关重要。由于疾病的高异质性和复杂性,该评估的性能很复杂,并且与高变异性相关。在这项工作中,我们解决了这个问题,并提出了一条深度学习管道,用于对胶质母细胞瘤患者进行全自动的端到端分析。我们的方法同时确定了肿瘤的子区域,包括第一步的肿瘤,周围肿瘤和手术腔,然后计算出遵循神经符号学(RANO)标准的当前响应评估的体积和双相测量。此外,我们引入了严格的手动注释过程,其随后是人类专家描绘肿瘤子区域的,并捕获其分割的信心,后来在训练深度学习模型时被使用。我们广泛的实验研究的结果超过了760次术前和504例从公共数据库获得的神经胶质瘤后患者(2021 - 2020年在19个地点获得)和临床治疗试验(47和69个地点,可用于公共数据库(在19个地点获得)(47和69个地点)术前/术后患者,2009-2011)并以彻底的定量,定性和统计分析进行了备份,表明我们的管道在手动描述时间的一部分中对术前和术后MRI进行了准确的分割(最高20比人更快。二维和体积测量与专家放射科医生非常吻合,我们表明RANO测量并不总是足以量化肿瘤负担。
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在这项工作中,我们考虑了成对的跨模式图像注册的任务,这可能会受益于仅利用培训时间可用的其他图像,而这些图像从与注册的图像不同。例如,我们专注于对准主体内的多参数磁共振(MPMR)图像,在T2加权(T2W)扫描和具有高B值(DWI $ _ {high-b} $)的T2加权(T2W)扫描和扩散加权扫描之间。为了在MPMR图像中应用局部性肿瘤,由于相应的功能的可用性,因此认为具有零B值(DWI $ _ {B = 0} $)的扩散扫描被认为更易于注册到T2W。我们使用仅训练成像模态DWI $ _ {b = 0} $从特权模式算法中提出了学习,以支持具有挑战性的多模式注册问题。我们根据356名前列腺癌患者的369组3D多参数MRI图像提出了实验结果图像对,与注册前7.96毫米相比。结果还表明,与经典的迭代算法和其他具有/没有其他方式的经典基于测试的基于学习的方法相比,提出的基于学习的注册网络具有可比或更高准确性的有效注册。这些比较的算法也未能在此具有挑战性的应用中产生DWI $ _ {High-B} $和T2W之间的任何明显改进的对齐。
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磁共振成像(MRI)是中风成像的中心方式。它被用来接受患者的治疗决定,例如选择患者进行静脉溶栓或血管内治疗。随后在住院期间使用MRI来通过可视化梗塞核心大小和位置来预测结果。此外,它可以用来表征中风病因,例如(心脏) - 栓塞和非胚胎中风之间的区分。基于计算机的自动医疗图像处理越来越多地进入临床常规。缺血性中风病变分割(ISLE)挑战的先前迭代有助于生成鉴定急性和急性缺血性中风病变分割的基准方法。在这里,我们介绍了一个专家注册的多中心MRI数据集,以分割急性到亚急性中风病变。该数据集包括400个多供应商MRI案例,中风病变大小,数量和位置的可变性很高。它分为n = 250的训练数据集和n = 150的测试数据集。所有培训数据将公开可用。测试数据集将仅用于模型验证,并且不会向公众发布。该数据集是Isles 2022挑战的基础,目的是找到算法方法,以实现缺血性中风的稳健和准确分割算法的开发和基准测试。
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Quantitative cephalometric analysis is the most widely used clinical and research tool in modern orthodontics. Accurate localization of cephalometric landmarks enables the quantification and classification of anatomical abnormalities, however, the traditional manual way of marking these landmarks is a very tedious job. Endeavours have constantly been made to develop automated cephalometric landmark detection systems but they are inadequate for orthodontic applications. The fundamental reason for this is that the amount of publicly available datasets as well as the images provided for training in these datasets are insufficient for an AI model to perform well. To facilitate the development of robust AI solutions for morphometric analysis, we organise the CEPHA29 Automatic Cephalometric Landmark Detection Challenge in conjunction with IEEE International Symposium on Biomedical Imaging (ISBI 2023). In this context, we provide the largest known publicly available dataset, consisting of 1000 cephalometric X-ray images. We hope that our challenge will not only derive forward research and innovation in automatic cephalometric landmark identification but will also signal the beginning of a new era in the discipline.
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在医学领域,MRI的地标检测在减少扫描计划,图像登记等中的任务中减少医疗技术人员努力方面发挥着重要作用。首先,88个地标在三个相应的观点中分布在三个相应的观点中 - 矢状,冠状动脉和轴向手动注释,专家临床技术人员的后期准则被划分解剖学,以便更好地定位现有地标,以便即使在斜扫描中也定位重要的地图标志性地标。为了克服有限的数据可用性,我们实施现实的数据增强以生成合成3D容量数据。我们使用修改后的HIGHRES3DNET模型来解决脑MRI容量的地标检测问题。为了在视觉上解释我们的培训模型,并从较弱的模型中辨别更强的模型,我们实现了梯度加权类激活映射(GRAC-CAM),它产生突出显示模型聚焦的区域的粗糙定位图。我们的实验表明,该方法显示出有利的结果,并且整个管道可以扩展到可变数量的地标和其他解剖。
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从磁共振成像(MRI)数据(称为颅骨条状)中去除非脑信号是许多神经图像分析流的组成部分。尽管它们很丰富,但通常是针对具有特定采集特性的图像量身定制的,即近乎各向异性的分辨率和T1加权(T1W)MRI对比度,这些分辨率在研究环境中很普遍。结果,现有的工具倾向于适应其他图像类型,例如在诊所常见的快速旋转回声(FSE)MRI中获得的厚切片。尽管近年来基于学习的大脑提取方法已获得吸引力,但这些方法面临着类似的负担,因为它们仅对训练过程中看到的图像类型有效。为了在成像协议的景观中实现强大的颅骨缠身,我们引入了Synthstrip,这是一种快速,基于学习的脑萃取工具。通过利用解剖学分割来生成具有解剖学,强度分布和远远超过现实医学图像范围的完全合成训练数据集,Synthstrip学会了成功推广到各种真实获得的大脑图像,从而消除了使用训练数据的需求目标对比。我们证明了合成条的功效对受试者人群的各种图像采集和决议的功效,从新生儿到成人。我们显示出与流行的颅骨基线的准确性的实质性提高 - 所有这些基线都采用单个训练有素的模型。我们的方法和标记的评估数据可在https://w3id.org/synthstrip上获得。
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Glioblastomas是最具侵略性的快速生长的主要脑癌,起源于大脑的胶质细胞。准确鉴定恶性脑肿瘤及其子区域仍然是医学图像分割中最具挑战性问题之一。脑肿瘤分割挑战(Brats)是自动脑胶质细胞瘤分割算法的流行基准,自于其启动。在今年的挑战中,Brats 2021提供了2,000名术前患者的最大多参数(MPMRI)数据集。在本文中,我们提出了两个深度学习框架的新聚合,即在术前MPMRI中的自动胶质母细胞瘤识别的Deepseg和NNU-Net。我们的集合方法获得了92.00,87.33和84.10和Hausdorff距离为3.81,8.91和16.02的骰子相似度分数,用于增强肿瘤,肿瘤核心和全肿瘤区域,单独进行。这些实验结果提供了证据表明它可以在临床上容易地应用,从而助攻脑癌预后,治疗计划和治疗反应监测。
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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。
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We present VoxelMorph, a fast learning-based framework for deformable, pairwise medical image registration. Traditional registration methods optimize an objective function for each pair of images, which can be time-consuming for large datasets or rich deformation models. In contrast to this approach, and building on recent learning-based methods, we formulate registration as a function that maps an input image pair to a deformation field that aligns these images. We parameterize the function via a convolutional neural network (CNN), and optimize the parameters of the neural network on a set of images. Given a new pair of scans, VoxelMorph rapidly computes a deformation field by directly evaluating the function. In this work, we explore two different training strategies. In the first (unsupervised) setting, we train the model to maximize standard image matching objective functions that are based on the image intensities. In the second setting, we leverage auxiliary segmentations available in the training data. We demonstrate that the unsupervised model's accuracy is comparable to state-of-the-art methods, while operating orders of magnitude faster. We also show that VoxelMorph trained with auxiliary data improves registration accuracy at test time, and evaluate the effect of training set size on registration. Our method promises to speed up medical image analysis and processing pipelines, while facilitating novel directions in learning-based registration and its applications. Our code is freely available at http://voxelmorph.csail.mit.edu.
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磁共振成像(MRI)数据由于设备制造商,扫描协议和受试者间变异性的差异而具有异质性。减轻MR图像异质性的一种常规方法是应用预处理转换,例如解剖学比对,体素重新采样,信号强度均衡,图像降解和利益区域的定位(ROI)。尽管预处理管道标准化了图像外观,但其对图像分割质量和深度神经网络(DNN)的其他下游任务的影响从未经过严格研究。在这里,我们报告了一项关于TCIA-GBM开源数据集的多模式MRI MRI脑癌图像分割的全面研究。我们的结果表明,大多数流行的标准化步骤对人工神经网络的性能没有任何价值。此外,预处理可以妨碍模型性能。我们建议,由于信号差异降低了图像标准化,图像强度归一化方法不会导致模型准确性。最后,如果根据临床相关的指标来衡量,我们表明了型型型在数据预处理中的贡献几乎可以忽略不计。我们表明,准确分析的唯一必不可少的转换是整个数据集的体素间距的统一。相反,非刚性地图集注册形式的解剖学对齐不是必需的,大多数强度均衡步骤不能提高模型的生产力。
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多发性硬化症(MS)是中枢神经系统的慢性炎症和退行性疾病,其特征在于,白色和灰质的外观与个体患者的神经症状和标志进行地平整相关。磁共振成像(MRI)提供了详细的体内结构信息,允许定量和分类MS病变,其批判性地通知疾病管理。传统上,MS病变在2D MRI切片上手动注释,一个流程效率低,易于观察室内误差。最近,已经提出了自动统计成像分析技术以基于MRI体素强度检测和分段段病变。然而,它们的有效性受到MRI数据采集技术的异质性和MS病变的外观的限制。通过直接从图像学习复杂的病变表现,深度学习技术已经在MS病变分割任务中取得了显着的突破。在这里,我们提供了全面审查最先进的自动统计和深度学习MS分段方法,并讨论当前和未来的临床应用。此外,我们审查了域适应等技术策略,以增强现实世界临床环境中的MS病变分段。
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Deformable image registration, i.e., the task of aligning multiple images into one coordinate system by non-linear transformation, serves as an essential preprocessing step for neuroimaging data. Recent research on deformable image registration is mainly focused on improving the registration accuracy using multi-stage alignment methods, where the source image is repeatedly deformed in stages by a same neural network until it is well-aligned with the target image. Conventional methods for multi-stage registration can often blur the source image as the pixel/voxel values are repeatedly interpolated from the image generated by the previous stage. However, maintaining image quality such as sharpness during image registration is crucial to medical data analysis. In this paper, we study the problem of anti-blur deformable image registration and propose a novel solution, called Anti-Blur Network (ABN), for multi-stage image registration. Specifically, we use a pair of short-term registration and long-term memory networks to learn the nonlinear deformations at each stage, where the short-term registration network learns how to improve the registration accuracy incrementally and the long-term memory network combines all the previous deformations to allow an interpolation to perform on the raw image directly and preserve image sharpness. Extensive experiments on both natural and medical image datasets demonstrated that ABN can accurately register images while preserving their sharpness. Our code and data can be found at https://github.com/anonymous3214/ABN
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域适应(DA)最近在医学影像社区提出了强烈的兴趣。虽然已经提出了大量DA技术进行了用于图像分割,但大多数这些技术已经在私有数据集或小公共可用数据集上验证。此外,这些数据集主要解决了单级问题。为了解决这些限制,与第24届医学图像计算和计算机辅助干预(Miccai 2021)结合第24届国际会议组织交叉模态域适应(Crossmoda)挑战。 Crossmoda是无监督跨型号DA的第一个大型和多级基准。挑战的目标是分割参与前庭施瓦新瘤(VS)的后续和治疗规划的两个关键脑结构:VS和Cochleas。目前,使用对比度增强的T1(CET1)MRI进行VS患者的诊断和监测。然而,使用诸如高分辨率T2(HRT2)MRI的非对比度序列越来越感兴趣。因此,我们创建了一个无人监督的跨模型分段基准。训练集提供注释CET1(n = 105)和未配对的非注释的HRT2(n = 105)。目的是在测试集中提供的HRT2上自动对HRT2进行单侧VS和双侧耳蜗分割(n = 137)。共有16支球队提交了评估阶段的算法。顶级履行团队达成的表现水平非常高(最佳中位数骰子 - vs:88.4%; Cochleas:85.7%)并接近完全监督(中位数骰子 - vs:92.5%;耳蜗:87.7%)。所有顶级执行方法都使用图像到图像转换方法将源域图像转换为伪目标域图像。然后使用这些生成的图像和为源图像提供的手动注释进行培训分割网络。
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