The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.

这项研究提出了一个基于移动网格参数化的端到端无监督的差异可变形登记框架。使用此参数化，可以使用其转换雅各布的决定因素和末端速度场的卷曲来建模。变形场的新模型具有三个重要优势。首先，它放松了对成本函数的显式正则化项和相应重量的需求。平滑度隐含在溶液中，从而导致物理上合理的变形场。其次，它通过适用于转换雅各布决定因素的明确约束来保证差异性。最后，它适用于心脏数据处理，因为该参数化的性质是根据​​径向和旋转成分定义变形场。通过在包括2D和3D心脏MRI扫描在内的三个不同数据集上评估拟议方法来研究算法的有效性。结果表明，所提出的框架在生成差异变换的同时优于现有的基于学习的方法和基于非学习的方法。

心肌活力的评估对于患有心肌梗塞的患者的诊断和治疗管理是必不可少的，并且心肌病理学的分类是本评估的关键。这项工作定义了医学图像分析的新任务，即进行心肌病理分割（MYOPS）结合三个序列的心脏磁共振（CMR）图像，该图像首次与Mycai 2020一起在Myops挑战中提出的。挑战提供了45个配对和预对准的CMR图像，允许算法将互补信息与三个CMR序列组合到病理分割。在本文中，我们提供了挑战的详细信息，从十五个参与者的作品调查，并根据五个方面解释他们的方法，即预处理，数据增强，学习策略，模型架构和后处理。此外，我们对不同因素的结果分析了结果，以检查关键障碍和探索解决方案的潜力，以及为未来的研究提供基准。我们得出结论，虽然报告了有前途的结果，但研究仍处于早期阶段，在成功应用于诊所之前需要更深入的探索。请注意，MyOPS数据和评估工具继续通过其主页（www.sdspeople.fudan.edu.cn/zhuangxiahai/0/myops20 /）注册注册。