视觉变形金刚（VIT）S表现出可观的全球和本地陈述的自我监督学习表现，可以转移到下游应用程序。灵感来自这些结果，我们介绍了一种新的自我监督学习框架，具有用于医学图像分析的定制代理任务。具体而言，我们提出：（i）以新的3D变压器为基础的型号，被称为往返变压器（Swin Unet），具有分层编码器，用于自我监督的预训练; （ii）用于学习人类解剖学潜在模式的定制代理任务。我们展示了来自各种身体器官的5,050个公共可用的计算机断层扫描（CT）图像的提出模型的成功预培训。通过微调超出颅穹窿（BTCV）分割挑战的预先调整训练模型和来自医疗细分牌组（MSD）数据集的分割任务，通过微调训练有素的模型来验证我们的方法的有效性。我们的模型目前是MSD和BTCV数据集的公共测试排行榜上的最先进的（即第1号）。代码：https://monai.io/research/swin-unetr.

Fully Convolutional Neural Networks (FCNNs) with contracting and expanding paths have shown prominence for the majority of medical image segmentation applications since the past decade. In FCNNs, the encoder plays an integral role by learning both global and local features and contextual representations which can be utilized for semantic output prediction by the decoder. Despite their success, the locality of convolutional layers in FCNNs, limits the capability of learning long-range spatial dependencies. Inspired by the recent success of transformers for Natural Language Processing (NLP) in long-range sequence learning, we reformulate the task of volumetric (3D) medical image segmentation as a sequence-to-sequence prediction problem. We introduce a novel architecture, dubbed as UNEt TRansformers (UNETR), that utilizes a transformer as the encoder to learn sequence representations of the input volume and effectively capture the global multi-scale information, while also following the successful "U-shaped" network design for the encoder and decoder. The transformer encoder is directly connected to a decoder via skip connections at different resolutions to compute the final semantic segmentation output. We have validated the performance of our method on the Multi Atlas Labeling Beyond The Cranial Vault (BTCV) dataset for multiorgan segmentation and the Medical Segmentation Decathlon (MSD) dataset for brain tumor and spleen segmentation tasks. Our benchmarks demonstrate new state-of-the-art performance on the BTCV leaderboard. Code: https://monai.io/research/unetr

脑肿瘤的语义分割是一个基本的医学图像分析任务，涉及多个MRI成像方式，可以帮助临床医生诊断患者并先后研究恶性实体的进展。近年来，完全卷积神经网络（FCNNS）方法已成为3D医学图像分割的事实标准。受欢迎的“U形”网络架构在不同的2D和3D语义分割任务和各种成像方式上实现了最先进的性能基准。然而，由于FCNNS中的卷积层的核心大小有限，它们的建模远程信息的性能是次优的，这可能导致具有可变尺寸的肿瘤分割的缺陷。另一方面，变压器模型在捕获多个域中的这种远程信息，包括自然语言处理和计算机视觉中的卓越功能。灵感来自视觉变形金刚的成功及其变体，我们提出了一种新的分割模型，被称为往返博物馆变压器（Swin Unet）。具体地，3D脑肿瘤语义分割的任务被重新重整为序列预测问题的序列，其中多模态输入数据被投射到嵌入的1D序列并用作作为编码器的分层SWIN变压器的输入。 SWIN变压器编码器通过利用移位窗口来提取五个不同分辨率的特征，以通过跳过连接在每个分辨率下连接到每个分辨率的基于FCNN的解码器。我们参与了Brats 2021分割挑战，我们所提出的模型在验证阶段的最佳方法中排名。代码：https://monai.io/research/swin-unetr.

Transformer-based models, capable of learning better global dependencies, have recently demonstrated exceptional representation learning capabilities in computer vision and medical image analysis. Transformer reformats the image into separate patches and realize global communication via the self-attention mechanism. However, positional information between patches is hard to preserve in such 1D sequences, and loss of it can lead to sub-optimal performance when dealing with large amounts of heterogeneous tissues of various sizes in 3D medical image segmentation. Additionally, current methods are not robust and efficient for heavy-duty medical segmentation tasks such as predicting a large number of tissue classes or modeling globally inter-connected tissues structures. Inspired by the nested hierarchical structures in vision transformer, we proposed a novel 3D medical image segmentation method (UNesT), employing a simplified and faster-converging transformer encoder design that achieves local communication among spatially adjacent patch sequences by aggregating them hierarchically. We extensively validate our method on multiple challenging datasets, consisting anatomies of 133 structures in brain, 14 organs in abdomen, 4 hierarchical components in kidney, and inter-connected kidney tumors). We show that UNesT consistently achieves state-of-the-art performance and evaluate its generalizability and data efficiency. Particularly, the model achieves whole brain segmentation task complete ROI with 133 tissue classes in single network, outperforms prior state-of-the-art method SLANT27 ensembled with 27 network tiles, our model performance increases the mean DSC score of the publicly available Colin and CANDI dataset from 0.7264 to 0.7444 and from 0.6968 to 0.7025, respectively.

特征图的分辨率对于医学图像分割至关重要。大多数现有用于医疗图像分割的基于变压器的网络都是U-NET样体系结构，其中包含一个编码器，该编码器利用一系列变压器块将输入医疗图像从高分辨率表示形式转换为低分辨率特征图和解码器这逐渐从低分辨率特征图中恢复了高分辨率表示。与以前的研究不同，在本文中，我们利用高分辨率网络（HRNET）的网络设计样式，用变压器块替换卷积层，并从变压器块生成的不同分辨率特征图中连续交换信息。本文介绍的新基于变压器的网络表示为高分辨率SWIN Transformer网络（HRSTNET）。广泛的实验表明，HRSTNET可以与基于最新的变压器类似于脑肿瘤分割的U-NET样结构（BRATS）2021和Medical Sementation Decathlon的肝数据集实现可比的性能。 HRSTNET代码将在https://github.com/auroua/hrstnet上公开获得。

作为新一代神经体系结构的变形金刚在自然语言处理和计算机视觉方面表现出色。但是，现有的视觉变形金刚努力使用有限的医学数据学习，并且无法概括各种医学图像任务。为了应对这些挑战，我们将Medformer作为数据量表变压器呈现为可推广的医学图像分割。关键设计结合了理想的电感偏差，线性复杂性的层次建模以及以空间和语义全局方式以线性复杂性的关注以及多尺度特征融合。 Medformer可以在不预训练的情况下学习微小至大规模的数据。广泛的实验表明，Medformer作为一般分割主链的潜力，在三个具有多种模式（例如CT和MRI）和多样化的医学靶标（例如，健康器官，疾病，疾病组织和肿瘤）的三个公共数据集上优于CNN和视觉变压器。我们将模型和评估管道公开可用，为促进广泛的下游临床应用提供固体基线和无偏比较。

Owing to the success of transformer models, recent works study their applicability in 3D medical segmentation tasks. Within the transformer models, the self-attention mechanism is one of the main building blocks that strives to capture long-range dependencies, compared to the local convolutional-based design. However, the self-attention operation has quadratic complexity which proves to be a computational bottleneck, especially in volumetric medical imaging, where the inputs are 3D with numerous slices. In this paper, we propose a 3D medical image segmentation approach, named UNETR++, that offers both high-quality segmentation masks as well as efficiency in terms of parameters and compute cost. The core of our design is the introduction of a novel efficient paired attention (EPA) block that efficiently learns spatial and channel-wise discriminative features using a pair of inter-dependent branches based on spatial and channel attention. Our spatial attention formulation is efficient having linear complexity with respect to the input sequence length. To enable communication between spatial and channel-focused branches, we share the weights of query and key mapping functions that provide a complimentary benefit (paired attention), while also reducing the overall network parameters. Our extensive evaluations on three benchmarks, Synapse, BTCV and ACDC, reveal the effectiveness of the proposed contributions in terms of both efficiency and accuracy. On Synapse dataset, our UNETR++ sets a new state-of-the-art with a Dice Similarity Score of 87.2%, while being significantly efficient with a reduction of over 71% in terms of both parameters and FLOPs, compared to the best existing method in the literature. Code: https://github.com/Amshaker/unetr_plus_plus.

最近，蒙面图像建模（MIM）由于其能力从大量未标记的数据中学习而引起了人们的关注，并且已被证明对涉及自然图像的各种视觉任务有效。同时，由于未标记的图像的数量高，预计3D医学图像中的自我监督学习的潜力预计将是巨大的，以及质量标签的费用和困难。但是，MIM对医学图像的适用性仍然不确定。在本文中，我们证明了掩盖的图像建模方法还可以推进3D医学图像分析，除了自然图像。我们研究掩盖图像建模策略如何从3D医学图像分割的角度利用性能作为代表性的下游任务：i）与天真的对比度学习相比，蒙版的图像建模方法可以加快监督培训的收敛性，甚至更快（1.40美元$ \ times $ \ times $ $ $ ）并最终产生更高的骰子分数； ii）预测具有较高掩盖比和相对较小的贴片大小的原始体素值是用于医学图像建模的非平凡的自我监督借口任务； iii）重建的轻质解码器或投影头设计对于3D医学图像上的掩盖图像建模非常有力，该图像加快了训练并降低成本； iv）最后，我们还研究了在不同的实际情况下使用不同图像分辨率和标记的数据比率的MIM方法的有效性。

变压器在计算机视觉中的成功吸引了医学成像社区越来越多的关注。特别是对于医学图像细分，已经介绍了许多基于卷积神经网络（CNN）和变压器的出色混合体系结构，并取得了令人印象深刻的性能。但是，将模块化变压器嵌入CNN中的大多数方法都难以发挥其全部潜力。在本文中，我们提出了一种新型的医学图像分割的混合体系结构，称为Phtrans，该架构可与主要构建基块中的变形金刚和CNN杂交，以产生来自全球和本地特征的层次结构表示，并适应性地汇总它们，旨在完全利用其优势以获得更好的优势。细分性能。具体而言，phtrans遵循U形编码器编码器设计，并在深层阶段引入平行的Hybird模块，其中卷积块和经过修改的3D SWIN变压器分别学习本地特征和全局依赖性，然后统一尺寸，统一尺寸输出以实现特征聚合。超出颅库和自动化心脏诊断挑战数据集以外的多ATLA标签的广泛实验结果证实了其有效性，始终超过了最先进的方法。该代码可在以下网址获得：https：//github.com/lseventeen/phtrans。

变形金刚占据了自然语言处理领域，最近影响了计算机视觉区域。在医学图像分析领域中，变压器也已成功应用于全栈临床应用，包括图像合成/重建，注册，分割，检测和诊断。我们的论文旨在促进变压器在医学图像分析领域的认识和应用。具体而言，我们首先概述了内置在变压器和其他基本组件中的注意机制的核心概念。其次，我们回顾了针对医疗图像应用程序量身定制的各种变压器体系结构，并讨论其局限性。在这篇综述中，我们调查了围绕在不同学习范式中使用变压器，提高模型效率及其与其他技术的耦合的关键挑战。我们希望这篇评论可以为读者提供医学图像分析领域的读者的全面图片。

计算机辅助医学图像分割已广泛应用于诊断和治疗，以获得靶器官和组织的形状和体积的临床有用信息。在过去的几年中，基于卷积神经网络（CNN）的方法（例如，U-Net）占主导地位，但仍遭受了不足的远程信息捕获。因此，最近的工作提出了用于医学图像分割任务的计算机视觉变压器变体，并获得了有希望的表现。这种变压器通过计算配对贴片关系来模拟远程依赖性。然而，它们促进了禁止的计算成本，尤其是在3D医学图像（例如，CT和MRI）上。在本文中，我们提出了一种称为扩张变压器的新方法，该方法在本地和全球范围内交替捕获的配对贴片关系进行自我关注。灵感来自扩张卷积核，我们以扩张的方式进行全球自我关注，扩大接收领域而不增加所涉及的斑块，从而降低计算成本。基于这种扩展变压器的设计，我们构造了一个用于3D医学图像分割的U形编码器解码器分层体系结构。 Synapse和ACDC数据集的实验表明，我们的D-Ager Model从头开始培训，以低计算成本从划痕训练，优于各种竞争力的CNN或基于变压器的分段模型，而不耗时的每训练过程。

目的：在手术规划之前，CT图像中肝血管的分割是必不可少的，并引起了医学图像分析界的广泛兴趣。由于结构复杂，对比度背景下，自动肝脏血管分割仍然特别具有挑战性。大多数相关的研究采用FCN，U-Net和V-Net变体作为骨干。然而，这些方法主要集中在捕获多尺度局部特征，这可能导致由于卷积运营商有限的地区接收领域而产生错误分类的体素。方法：我们提出了一种强大的端到端血管分割网络，通过将SWIN变压器扩展到3D并采用卷积和自我关注的有效组合，提出了一种被称为电感偏置的多头注意船网（IBIMHAV-NET）的稳健端到端血管分割网络。在实践中，我们介绍了Voxel-Wise嵌入而不是修补程序嵌入，以定位精确的肝脏血管素，并采用多尺度卷积运营商来获得局部空间信息。另一方面，我们提出了感应偏置的多头自我关注，其学习从初始化的绝对位置嵌入的归纳偏置相对位置嵌入嵌入。基于此，我们可以获得更可靠的查询和键矩阵。为了验证我们模型的泛化，我们测试具有不同结构复杂性的样本。结果：我们对3Dircadb数据集进行了实验。四种测试病例的平均骰子和敏感性为74.8％和77.5％，超过现有深度学习方法的结果和改进的图形切割方法。结论：拟议模型IBIMHAV-Net提供一种具有交错架构的自动，精确的3D肝血管分割，可更好地利用CT卷中的全局和局部空间特征。它可以进一步扩展到其他临床数据。

Convolutional Neural Networks (CNNs) with U-shaped architectures have dominated medical image segmentation, which is crucial for various clinical purposes. However, the inherent locality of convolution makes CNNs fail to fully exploit global context, essential for better recognition of some structures, e.g., brain lesions. Transformers have recently proven promising performance on vision tasks, including semantic segmentation, mainly due to their capability of modeling long-range dependencies. Nevertheless, the quadratic complexity of attention makes existing Transformer-based models use self-attention layers only after somehow reducing the image resolution, which limits the ability to capture global contexts present at higher resolutions. Therefore, this work introduces a family of models, dubbed Factorizer, which leverages the power of low-rank matrix factorization for constructing an end-to-end segmentation model. Specifically, we propose a linearly scalable approach to context modeling, formulating Nonnegative Matrix Factorization (NMF) as a differentiable layer integrated into a U-shaped architecture. The shifted window technique is also utilized in combination with NMF to effectively aggregate local information. Factorizers compete favorably with CNNs and Transformers in terms of accuracy, scalability, and interpretability, achieving state-of-the-art results on the BraTS dataset for brain tumor segmentation and ISLES'22 dataset for stroke lesion segmentation. Highly meaningful NMF components give an additional interpretability advantage to Factorizers over CNNs and Transformers. Moreover, our ablation studies reveal a distinctive feature of Factorizers that enables a significant speed-up in inference for a trained Factorizer without any extra steps and without sacrificing much accuracy. The code and models are publicly available at https://github.com/pashtari/factorizer.

Collecting large-scale medical datasets with fully annotated samples for training of deep networks is prohibitively expensive, especially for 3D volume data. Recent breakthroughs in self-supervised learning (SSL) offer the ability to overcome the lack of labeled training samples by learning feature representations from unlabeled data. However, most current SSL techniques in the medical field have been designed for either 2D images or 3D volumes. In practice, this restricts the capability to fully leverage unlabeled data from numerous sources, which may include both 2D and 3D data. Additionally, the use of these pre-trained networks is constrained to downstream tasks with compatible data dimensions. In this paper, we propose a novel framework for unsupervised joint learning on 2D and 3D data modalities. Given a set of 2D images or 2D slices extracted from 3D volumes, we construct an SSL task based on a 2D contrastive clustering problem for distinct classes. The 3D volumes are exploited by computing vectored embedding at each slice and then assembling a holistic feature through deformable self-attention mechanisms in Transformer, allowing incorporating long-range dependencies between slices inside 3D volumes. These holistic features are further utilized to define a novel 3D clustering agreement-based SSL task and masking embedding prediction inspired by pre-trained language models. Experiments on downstream tasks, such as 3D brain segmentation, lung nodule detection, 3D heart structures segmentation, and abnormal chest X-ray detection, demonstrate the effectiveness of our joint 2D and 3D SSL approach. We improve plain 2D Deep-ClusterV2 and SwAV by a significant margin and also surpass various modern 2D and 3D SSL approaches.

卷积神经网络（CNN）已成为医疗图像分割任务的共识。但是，由于卷积操作的性质，它们在建模长期依赖性和空间相关性时受到限制。尽管最初开发了变压器来解决这个问题，但它们未能捕获低级功能。相比之下，证明本地和全球特征对于密集的预测至关重要，例如在具有挑战性的环境中细分。在本文中，我们提出了一种新型方法，该方法有效地桥接了CNN和用于医学图像分割的变压器。具体而言，我们使用开创性SWIN变压器模块和一个基于CNN的编码器设计两个多尺度特征表示。为了确保从上述两个表示获得的全局和局部特征的精细融合，我们建议在编码器编码器结构的跳过连接中提出一个双层融合（DLF）模块。在各种医学图像分割数据集上进行的广泛实验证明了Hiformer在计算复杂性以及定量和定性结果方面对其他基于CNN的，基于变压器和混合方法的有效性。我们的代码可在以下网址公开获取：https：//github.com/amirhossein-kz/hiformer

An increasing number of public datasets have shown a marked clinical impact on assessing anatomical structures. However, each of the datasets is small, partially labeled, and rarely investigates severe tumor subjects. Moreover, current models are limited to segmenting specific organs/tumors, which can not be extended to novel domains and classes. To tackle these limitations, we introduce embedding learned from Contrastive Language-Image Pre-training (CLIP) to segmentation models, dubbed the CLIP-Driven Universal Model. The Universal Model can better segment 25 organs and 6 types of tumors by exploiting the semantic relationship between abdominal structures. The model is developed from an assembly of 14 datasets with 3,410 CT scans and evaluated on 6,162 external CT scans from 3 datasets. We rank first on the public leaderboard of the Medical Segmentation Decathlon (MSD) and achieve the state-of-the-art results on Beyond The Cranial Vault (BTCV). Compared with dataset-specific models, the Universal Model is computationally more efficient (6x faster), generalizes better to CT scans from varying sites, and shows stronger transfer learning performance on novel tasks. The design of CLIP embedding enables the Universal Model to be easily extended to new classes without catastrophically forgetting the previously learned classes.

随着计算机技术的开发，人工智能已经出现了各种模型。在自然语言处理（NLP）成功之后，变压器模型已应用于计算机视觉（CV）。放射科医生在当今迅速发展的医疗领域中继续面临多重挑战，例如增加工作量和增加的诊断需求。尽管以前有一些常规的肺癌检测方法，但仍需要提高其准确性，尤其是在现实的诊断情况下。本文创造性地提出了一种基于有效变压器的分割方法，并将其应用于医学图像分析。该算法通过分析肺癌数据来完成肺癌分类和细分的任务，并旨在为医务人员提供有效的技术支持。此外，我们在各个方面进行了评估并比较了结果。对于分类任务，通过定期培训和SWIN-B在两项决议中通过预训练的最高准确性可高达82.3％。对于分割任务，我们使用预训练来帮助模型提高实验的准确性。这三个模型的准确性达到95％以上。实验表明该算法可以很好地应用于肺癌分类和分割任务。

多年来，卷积神经网络（CNN）已成为多种计算机视觉任务的事实上的标准。尤其是，基于开创性体系结构（例如具有跳过连接的U形模型）或具有金字塔池的Artous卷积的深度神经网络已针对广泛的医学图像分析任务量身定制。此类架构的主要优点是它们容易拘留多功能本地功能。然而，作为一般共识，CNN无法捕获由于卷积操作的固有性能的内在特性而捕获长期依赖性和空间相关性。另外，从全球信息建模中获利的变压器源于自我发项机制，最近在自然语言处理和计算机视觉方面取得了出色的表现。然而，以前的研究证明，局部和全局特征对于密集预测的深层模型至关重要，例如以不同的形状和配置对复杂的结构进行分割。为此，本文提出了TransDeeplab，这是一种新型的DeepLab样纯变压器，用于医学图像分割。具体而言，我们用移动的窗口利用层次旋转式变形器来扩展DeepLabV3并建模非常有用的空间金字塔池（ASPP）模块。对相关文献的彻底搜索结果是，我们是第一个用基于纯变压器模型对开创性DeepLab模型进行建模的人。关于各种医学图像分割任务的广泛实验证明，我们的方法在视觉变压器和基于CNN的方法的合并中表现出色或与大多数当代作品相提并论，并显着降低了模型复杂性。代码和训练有素的模型可在https://github.com/rezazad68/transdeeplab上公开获得

在过去的十年中，卷积神经网络（Convnets）主导了医学图像分析领域。然而，发现脉搏的性能仍然可以受到它们无法模拟图像中体素之间的远程空间关系的限制。最近提出了众多视力变压器来解决哀悼缺点，在许多医学成像应用中展示最先进的表演。变压器可以是用于图像配准的强烈候选者，因为它们的自我注意机制能够更精确地理解移动和固定图像之间的空间对应。在本文中，我们呈现透射帧，一个用于体积医学图像配准的混合变压器-Cromnet模型。我们还介绍了三种变速器的变形，具有两个散晶变体，确保了拓扑保存的变形和产生良好校准的登记不确定性估计的贝叶斯变体。使用来自两个应用的体积医学图像的各种现有的登记方法和变压器架构进行广泛验证所提出的模型：患者间脑MRI注册和幻影到CT注册。定性和定量结果表明，传输和其变体导致基线方法的实质性改进，展示了用于医学图像配准的变压器的有效性。

Transformers have made remarkable progress towards modeling long-range dependencies within the medical image analysis domain. However, current transformer-based models suffer from several disadvantages: (1) existing methods fail to capture the important features of the images due to the naive tokenization scheme; (2) the models suffer from information loss because they only consider single-scale feature representations; and (3) the segmentation label maps generated by the models are not accurate enough without considering rich semantic contexts and anatomical textures. In this work, we present CASTformer, a novel type of adversarial transformers, for 2D medical image segmentation. First, we take advantage of the pyramid structure to construct multi-scale representations and handle multi-scale variations. We then design a novel class-aware transformer module to better learn the discriminative regions of objects with semantic structures. Lastly, we utilize an adversarial training strategy that boosts segmentation accuracy and correspondingly allows a transformer-based discriminator to capture high-level semantically correlated contents and low-level anatomical features. Our experiments demonstrate that CASTformer dramatically outperforms previous state-of-the-art transformer-based approaches on three benchmarks, obtaining 2.54%-5.88% absolute improvements in Dice over previous models. Further qualitative experiments provide a more detailed picture of the model's inner workings, shed light on the challenges in improved transparency, and demonstrate that transfer learning can greatly improve performance and reduce the size of medical image datasets in training, making CASTformer a strong starting point for downstream medical image analysis tasks.