524 research outputs found
Non-iterative Coarse-to-fine Transformer Networks for Joint Affine and Deformable Image Registration
Image registration is a fundamental requirement for medical image analysis.
Deep registration methods based on deep learning have been widely recognized
for their capabilities to perform fast end-to-end registration. Many deep
registration methods achieved state-of-the-art performance by performing
coarse-to-fine registration, where multiple registration steps were iterated
with cascaded networks. Recently, Non-Iterative Coarse-to-finE (NICE)
registration methods have been proposed to perform coarse-to-fine registration
in a single network and showed advantages in both registration accuracy and
runtime. However, existing NICE registration methods mainly focus on deformable
registration, while affine registration, a common prerequisite, is still
reliant on time-consuming traditional optimization-based methods or extra
affine registration networks. In addition, existing NICE registration methods
are limited by the intrinsic locality of convolution operations. Transformers
may address this limitation for their capabilities to capture long-range
dependency, but the benefits of using transformers for NICE registration have
not been explored. In this study, we propose a Non-Iterative Coarse-to-finE
Transformer network (NICE-Trans) for image registration. Our NICE-Trans is the
first deep registration method that (i) performs joint affine and deformable
coarse-to-fine registration within a single network, and (ii) embeds
transformers into a NICE registration framework to model long-range relevance
between images. Extensive experiments with seven public datasets show that our
NICE-Trans outperforms state-of-the-art registration methods on both
registration accuracy and runtime.Comment: Accepted at International Conference on Medical Image Computing and
Computer Assisted Intervention (MICCAI 2023
Medical imaging analysis with artificial neural networks
Given that neural networks have been widely reported in the research community of medical imaging, we provide a focused literature survey on recent neural network developments in computer-aided diagnosis, medical image segmentation and edge detection towards visual content analysis, and medical image registration for its pre-processing and post-processing, with the aims of increasing awareness of how neural networks can be applied to these areas and to provide a foundation for further research and practical development. Representative techniques and algorithms are explained in detail to provide inspiring examples illustrating: (i) how a known neural network with fixed structure and training procedure could be applied to resolve a medical imaging problem; (ii) how medical images could be analysed, processed, and characterised by neural networks; and (iii) how neural networks could be expanded further to resolve problems relevant to medical imaging. In the concluding section, a highlight of comparisons among many neural network applications is included to provide a global view on computational intelligence with neural networks in medical imaging
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
Medical image registration using unsupervised deep neural network: A scoping literature review
In medicine, image registration is vital in image-guided interventions and
other clinical applications. However, it is a difficult subject to be addressed
which by the advent of machine learning, there have been considerable progress
in algorithmic performance has recently been achieved for medical image
registration in this area. The implementation of deep neural networks provides
an opportunity for some medical applications such as conducting image
registration in less time with high accuracy, playing a key role in countering
tumors during the operation. The current study presents a comprehensive scoping
review on the state-of-the-art literature of medical image registration studies
based on unsupervised deep neural networks is conducted, encompassing all the
related studies published in this field to this date. Here, we have tried to
summarize the latest developments and applications of unsupervised deep
learning-based registration methods in the medical field. Fundamental and main
concepts, techniques, statistical analysis from different viewpoints,
novelties, and future directions are elaborately discussed and conveyed in the
current comprehensive scoping review. Besides, this review hopes to help those
active readers, who are riveted by this field, achieve deep insight into this
exciting field
Contrastive Registration for Unsupervised Medical Image Segmentation
Medical image segmentation is a relevant task as it serves as the first step
for several diagnosis processes, thus it is indispensable in clinical usage.
Whilst major success has been reported using supervised techniques, they assume
a large and well-representative labelled set. This is a strong assumption in
the medical domain where annotations are expensive, time-consuming, and
inherent to human bias. To address this problem, unsupervised techniques have
been proposed in the literature yet it is still an open problem due to the
difficulty of learning any transformation pattern. In this work, we present a
novel optimisation model framed into a new CNN-based contrastive registration
architecture for unsupervised medical image segmentation. The core of our
approach is to exploit image-level registration and feature-level from a
contrastive learning mechanism, to perform registration-based segmentation.
Firstly, we propose an architecture to capture the image-to-image
transformation pattern via registration for unsupervised medical image
segmentation. Secondly, we embed a contrastive learning mechanism into the
registration architecture to enhance the discriminating capacity of the network
in the feature-level. We show that our proposed technique mitigates the major
drawbacks of existing unsupervised techniques. We demonstrate, through
numerical and visual experiments, that our technique substantially outperforms
the current state-of-the-art unsupervised segmentation methods on two major
medical image datasets.Comment: 11 pages, 3 figure
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