412 research outputs found
Recursive Cascaded Networks for Unsupervised Medical Image Registration
We present recursive cascaded networks, a general architecture that enables
learning deep cascades, for deformable image registration. The proposed
architecture is simple in design and can be built on any base network. The
moving image is warped successively by each cascade and finally aligned to the
fixed image; this procedure is recursive in a way that every cascade learns to
perform a progressive deformation for the current warped image. The entire
system is end-to-end and jointly trained in an unsupervised manner. In
addition, enabled by the recursive architecture, one cascade can be iteratively
applied for multiple times during testing, which approaches a better fit
between each of the image pairs. We evaluate our method on 3D medical images,
where deformable registration is most commonly applied. We demonstrate that
recursive cascaded networks achieve consistent, significant gains and
outperform state-of-the-art methods. The performance reveals an increasing
trend as long as more cascades are trained, while the limit is not observed.
Code is available at https://github.com/microsoft/Recursive-Cascaded-Networks.Comment: Accepted to ICCV 201
CNN-based Lung CT Registration with Multiple Anatomical Constraints
Deep-learning-based registration methods emerged as a fast alternative to
conventional registration methods. However, these methods often still cannot
achieve the same performance as conventional registration methods because they
are either limited to small deformation or they fail to handle a superposition
of large and small deformations without producing implausible deformation
fields with foldings inside.
In this paper, we identify important strategies of conventional registration
methods for lung registration and successfully developed the deep-learning
counterpart. We employ a Gaussian-pyramid-based multilevel framework that can
solve the image registration optimization in a coarse-to-fine fashion.
Furthermore, we prevent foldings of the deformation field and restrict the
determinant of the Jacobian to physiologically meaningful values by combining a
volume change penalty with a curvature regularizer in the loss function.
Keypoint correspondences are integrated to focus on the alignment of smaller
structures.
We perform an extensive evaluation to assess the accuracy, the robustness,
the plausibility of the estimated deformation fields, and the transferability
of our registration approach. We show that it achieves state-of-the-art results
on the COPDGene dataset compared to conventional registration method with much
shorter execution time. In our experiments on the DIRLab exhale to inhale lung
registration, we demonstrate substantial improvements (TRE below mm) over
other deep learning methods. Our algorithm is publicly available at
https://grand-challenge.org/algorithms/deep-learning-based-ct-lung-registration/
A Survey on Deep Learning in Medical Image Registration: New Technologies, Uncertainty, Evaluation Metrics, and Beyond
Over the past decade, deep learning technologies have greatly advanced the
field of medical image registration. The initial developments, such as
ResNet-based and U-Net-based networks, laid the groundwork for deep
learning-driven image registration. Subsequent progress has been made in
various aspects of deep learning-based registration, including similarity
measures, deformation regularizations, and uncertainty estimation. These
advancements have not only enriched the field of deformable image registration
but have also facilitated its application in a wide range of tasks, including
atlas construction, multi-atlas segmentation, motion estimation, and 2D-3D
registration. In this paper, we present a comprehensive overview of the most
recent advancements in deep learning-based image registration. We begin with a
concise introduction to the core concepts of deep learning-based image
registration. Then, we delve into innovative network architectures, loss
functions specific to registration, and methods for estimating registration
uncertainty. Additionally, this paper explores appropriate evaluation metrics
for assessing the performance of deep learning models in registration tasks.
Finally, we highlight the practical applications of these novel techniques in
medical imaging and discuss the future prospects of deep learning-based image
registration
Improving Misaligned Multi-modality Image Fusion with One-stage Progressive Dense Registration
Misalignments between multi-modality images pose challenges in image fusion,
manifesting as structural distortions and edge ghosts. Existing efforts
commonly resort to registering first and fusing later, typically employing two
cascaded stages for registration,i.e., coarse registration and fine
registration. Both stages directly estimate the respective target deformation
fields. In this paper, we argue that the separated two-stage registration is
not compact, and the direct estimation of the target deformation fields is not
accurate enough. To address these challenges, we propose a Cross-modality
Multi-scale Progressive Dense Registration (C-MPDR) scheme, which accomplishes
the coarse-to-fine registration exclusively using a one-stage optimization,
thus improving the fusion performance of misaligned multi-modality images.
Specifically, two pivotal components are involved, a dense Deformation Field
Fusion (DFF) module and a Progressive Feature Fine (PFF) module. The DFF
aggregates the predicted multi-scale deformation sub-fields at the current
scale, while the PFF progressively refines the remaining misaligned features.
Both work together to accurately estimate the final deformation fields. In
addition, we develop a Transformer-Conv-based Fusion (TCF) subnetwork that
considers local and long-range feature dependencies, allowing us to capture
more informative features from the registered infrared and visible images for
the generation of high-quality fused images. Extensive experimental analysis
demonstrates the superiority of the proposed method in the fusion of misaligned
cross-modality images
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