Deformable Image Registration (DIR) is essential for aligning medical images that exhibit anatomical variations, facilitating applications such as disease tracking and radiotherapy planning. While classical iterative methods and deep learning approaches have achieved success in DIR, they are often hindered by computational inefficiency or poor generalization. In this paper, we introduce GaussianDIR, a novel, case-specific optimization DIR method inspired by 3D Gaussian splatting. In general, GaussianDIR represents image deformations using a sparse set of mobile and flexible Gaussian primitives, each defined by a center position, covariance, and local rigid transformation. This compact and explicit representation reduces noise and computational overhead while improving interpretability. Furthermore, the movement of individual voxel is derived via blending the local rigid transformation of the neighboring Gaussian primitives. By this, GaussianDIR captures both global smoothness and local rigidity as well as reduces the computational burden. To address varying levels of deformation complexity, GaussianDIR also integrates an adaptive density control mechanism that dynamically adjusts the density of Gaussian primitives. Additionally, we employ multi-scale Gaussian primitives to capture both coarse and fine deformations, reducing optimization to local minima. Experimental results on brain MRI, lung CT, and cardiac MRI datasets demonstrate that GaussianDIR outperforms existing DIR methods in both accuracy and efficiency, highlighting its potential for clinical applications. Finally, as a training-free approach, it challenges the stereotype that iterative methods are inherently slow and transcend the limitations of poor generalization.
A Deep Learning Framework for Unsupervised Affine and Deformable Image Registration
Image Sciences Institute, University Medical Center Utrecht and Utrecht University（乌得勒支大学医学中心与乌得勒支大学影像科学研究所）；Division of Image Processing of the Leiden University Medical Center（莱顿大学医学中心图像处理部）
End-to-End Unsupervised Deformable Image Registration with a Convolutional Neural Network
Image Sciences Institute, University Medical Center Utrecht（乌得勒支大学医学中心图像科学研究所）；Division of Image Processing, Leiden University Medical Center（莱顿大学医学中心图像处理部）
Domain-Shift Immunity in Deep Deformable Registration via Local Feature Representations
Kahlert School of Computing（卡尔伯特计算学校）；Scientific Computing and Imaging Institute（科学计算与成像研究所）；University of Utah（犹他大学）；Department of Biomedical Engineering（生物医学工程系）
Weakly-Supervised Learning of Metric Aggregations for Deformable Image Registration
Research institute for signals, systems and computational intelligence, sinc(i), FICH-UNL/CONICET（信号、系统与计算智能研究所 sinc(i)，FICH-UNL/CONICET）；University of Oxford（牛津大学）；TheraPanacea；CentraleSupelec（中央理工-高等电力学院）；Universite Paris-Saclay（巴黎-萨克雷大学）
Learning Deformable Image Registration from Optimization: Perspective, Modules, Bilevel Training and Beyond
Dalian University of Technology（大连理工大学）；Guilin University of Electronic Technology（桂林电子科技大学）；Children’s Hospital of Philadelphia（费城儿童医院）；University of Pennsylvania（宾夕法尼亚大学）
Vector Field Attention for Deformable Image Registration
Johns Hopkins University（约翰斯·霍普金斯大学）；Johns Hopkins School of Medicine（约翰斯·霍普金斯医学院）；National Institute on Aging（美国国家老龄化研究所）；National Institute of Health（美国国立卫生研究院）
Evaluation of Deformable Image Registration under Alignment-Regularity Trade-off
Technical University of Munich (TUM)（慕尼黑技术大学）；TUM University Hospital, Munich, Germany（慕尼黑技术大学医院）；Munich Center for Machine Learning (MCML)（慕尼黑机器学习中心）；Department of Computing, Imperial College London（伦敦帝国理工学院计算机系）
Recursive Deformable Image Registration Network with Mutual Attention
The Kennedy Institute of Rheumatology（肯尼迪风湿病学研究所）；University of Oxford（牛津大学）；Big Data Institute（大数据研究所）；Imperial College London（伦敦帝国学院）；Nuffield Department of Population Health, University of Oxford（牛津大学纳菲尔德人口健康系）
Progressive Retinal Image Registration via Global and Local Deformable Transformations
School of Computer Science Wuhan University Wuhan, China；School of Computer Science The University of Sydney Sydney, Australia；School of Computer Science Wuhan University Wuhan, China yuliang\；Institute for Infocomm Research A STAR Singapore cheng\
Linear and Deformable Image Registration with 3D Convolutional Neural Networks
University of Bern（伯尔尼大学）；CentraleSupélec（中央理工-高等电力学院）；Université Paris-Saclay（巴黎-萨克雷大学）；Groupe Hospitalier Cochin-Hôtel Dieu（科钦-主宫医院集团）；Université Paris Descartes（巴黎笛卡尔大学）；TheraPanacea
3D deformable registration of longitudinal abdominopelvic CT images using unsupervised deep learning
University of Cambridge（剑桥大学）；Cancer Research UK Cambridge Centre（英国癌症研究中心剑桥中心）；Medical University Vienna（维也纳医科大学）；Cambridge University Hospitals National Health Service (NHS) Foundation Trust（剑桥大学医院国民保健服务基金会信托）；Eindhoven University of Technology（埃因霍温理工大学）；Leiden University（莱顿大学）；University College London（伦敦大学学院）；Cancer Research UK Cambridge Institute（英国癌症研究中心剑桥研究所）
Unsupervised Deformable Image Registration with Local-Global Attention and Image Decomposition
Institute of Medical Technology, Peking University Health Science Center（北京大学医学部医学技术研究所）；National Institute of Health Data Science, Peking University（北京大学国家健康数据科学研究院）；Department of Radiology, Peking University Third Hospital（北京大学第三医院放射科）；Department of Pediatrics, Peking University First Hospital（北京大学第一医院儿科）；Pediatric Epilepsy Center, Peking University First Hospital（北京大学第一医院儿童癫痫中心）；School of Biological Science and Medical Engineering, Southeast University（东南大学生物科学与医学工程学院）；Institute for Artificial Intelligence, Peking University（北京大学人工智能研究院）
A Transformer-based Network for Deformable Medical Image Registration
Huazhong University of Science and Technology（华中科技大学）；College of Life Science and Technology, Huazhong University of Science and Technology（华中科技大学生命科学与技术学院）
A coarse-to-fine framework for unsupervised multi-contrast MR image deformable registration with dual consistency constraint
Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences（中国科学院深圳先进技术研究院保罗·C·劳特伯生物医学成像研究中心）；Pengcheng Laboratory（鹏城实验室）；Pazhou Lab（琶洲实验室）；Guizhou Provincial People’s Hospital（贵州省人民医院）
