Diffusion Tensor Magnetic Resonance Imaging (DTI) is a non-invasive technique for studying brain structure in vivo by measuring the diffusion properties of water molecules. Unlike conventional medical imaging that captures scalar intensity data, DTI data is typically stored as a 4D volume, where each voxel in 3D space is a 3×3 Cartesian tensor. DTI characterizes tensor-based diffusion profiles and captures information about the orientation of fiber bundles. During the alignment process, voxels need to be spatially transformed while maintaining the correspondence of tensor orientations, which leads to complex computations. Traditional DTI registration methods often suffer from slow iteration speed and low accuracy, posing challenges for clinical applications. In this paper, a novel DTI Registration method Based on Parallel Dual-channel Voxel Morph (DTI-RBPDV) is proposed. The core of the method is a two-branch convolutional neural network architecture. With a view to enhancing the alignment performance, it processes two input patterns simultaneously: (1) fractional anisotropy (FA) images and (2) principal eigenvectors from to-be-aligned and fixed DTI volumes to enhance the accuracy of deformation field prediction. In the network decoder layer, integration of attention mechanisms has also been implemented. These channel space attention modules dynamically highlight salient anatomical features and orientation consistency, improving the model's sensitivity to key structural alignments. Experimental results show that DTI-RBPDV effectively addresses the limitations of slow iterative computation and the challenges of applying deep learning to high-dimensional DTI data by significantly improving the registration accuracy and computational speed.

Modern managed language runtimes (e.g., Java, Go and C#) rely on garbage collection (GC) mechanisms to automatically allocate and reclaim in-memory objects. The efficiency of GC implementations can greatly impact the overall performance of runtime-based applications. To improve GC performance, the academic and industrial communities have proposed several approaches to evaluate the GC implementations in an individual runtime. However, these approaches target a specific managed language (e.g., Java), and cannot be used to compare the GC implementations in different runtimes. In this paper, we propose GEAR, an automated approach to construct consistent GC workloads for different managed language runtimes, which can further be used to evaluate GC implementations across different runtimes. Specifically, we design a group of runtime-agnostic Memory Operation Primitives (MOP), which can portray the memory usage information that influences GC. GEAR can further automatically convert a MOP program into runtime-specific programs for the target runtimes, which serve as a consistent GC workload for different runtimes. To build MOP programs with real-world GC workloads, we instrument the commonly-used runtime Java Virtual Machine (JVM) to collect the memory operation trace during a Java application's execution, and then transform the memory operation trace into a MOP program. The experimental result on three widely-used runtimes (i.e., Java, Go and C#) shows that GEAR can generate consistent GC workloads for different runtimes. We further conduct a comprehensive study on these three runtimes, and reveal some interesting findings about their GC performance, providing useful guidance for improving their GC implementations.

Punctate White Matter Damage (PWMD) is a common neonatal brain disease, which can easily cause neurological disorder and strongly affect life quality in terms of neuromotor and cognitive performance. Especially, at the neonatal stage, the best cure time can be easily missed because PWMD is not conducive to the diagnosis based on current existing methods. The lesion of PWMD is relatively straightforward on T1-weighted Magnetic Resonance Imaging (T1 MRI), showing semi-oval, cluster or linear high signals. Diffusion Tensor Magnetic Resonance Image (DT-MRI, referred to as DTI) is a noninvasive technique that can be used to study brain microstructures in vivo, and provide information on movement and cognition-related nerve fiber tracts. Therefore, a new method was proposed to use T1 MRI combined with DTI for better neonatal PWMD analysis based on DTI super-resolution and multi-modality image registration. First, after preprocessing, neonatal DTI super-resolution was performed with the three times B-spline interpolation algorithm based on the Log-Euclidean space to improve DTIs’ resolution to fit the T1 MRIs and facilitate nerve fiber tractography. Second, the symmetric diffeomorphic registration algorithm and inverse b0 image were selected for multi-modality image registration of DTI and T1 MRI. Finally, the 3D lesion models were combined with fiber tractography results to analyze and predict the degree of PWMD lesions affecting fiber tracts. Extensive experiments demonstrated the effectiveness and super performance of our proposed method. This streamlined technique can play an essential auxiliary role in diagnosing and treating neonatal PWMD.

There are relatively few studies on the multi-coil reconstruction task of existing Magnetic Resonance Imaging (MRI) methods, as there are problems with insufficient reconstruction details, high memory occupation during training, etc. Therefore, a new Dual-domain Parallel Fusion Reconstruction Network (DPFNet) is proposed in this paper. The whole network consists of coil sensitivity graph estimation module, dual domain feature extraction module, dual domain dynamic error correction module, and dual domain dynamic fusion module. A U-Net has been used as the backbone network. The network reconstructs under-sampled MRI images and K-space data simultaneously in two branches of the image domain and K-space domain, and the fusion module realizes the reconstruction information interaction between the two branches. In addition, a new dual domain consistency loss is also proposed, which reduces the error between the same MRI slice image and K-space data with dual domain output, and achieves high quality reconstruction. In this paper, a series of comparative experiments and ablation experiments are conducted in the open Calgary-Campinas-359 brain MRI data set. The results of the experiments show that the proposed DPFNet achieves the most advanced level at present and is superior to other traditional algorithms and reconstruction methods based on deep learning. In particular, the reconstruction results from Cartesian sampling are very good.

Active Shape Model (ASM) has been successfully applied in the segmentation of Diffusion Tensor Magnetic Resonance Image (DT-MRI, referred to as DTI) of brain. However, due to multiple anatomical structure types, irregular shapes, small gray-scale and large amount of these images, perfect segmentation performance could not be achieved. Especially, it is sensitive to initial values with high computational complexity. In this paper, we introduce the gray information of multiple atlases and the prior information of target shapes into the ASM and propose the Multi-Atlas Active Shape Model (referred to as MA-ASM) approach for DTI segmentation. It was evaluated in a manually labeled database with 7 Region of Interest (ROI)s for each of 20 subjects. In comparison with the state of art method of STAPLE (Simultaneous Truth Performance Level Estimation), the proposed algorithm was closer to the manual segmentation shape by subjective visual effects, and had higher overlap rates and lower error detection rates on quantitative analysis than STAPLE.

Hue component is generally denoted by angle value, so the conventional edge detection operators are incapable to accurately detect edges of hue component. As a result, the popular methods of colour image edge detection usually omit the role of hue component, thus missing some edges caused by hue changes. The authors propose a novel colour edge detection method based on the fusion of hue component and principal component analysis to solve the above problems. First, a novel computational method of hue difference is defined, and then it is applied to classical gradient operators to obtain accurate edges for hue component. Moreover, complete object edges can be obtained by using the edge fusion of the first principal component and hue component of colour image with low‐computational complexity. Experimental results show that the proposed approach not only can act on hue component directly and obtain accurate edges caused by hue changes, but also is effective and easy to implement.

The existing lexicographical ordering approaches respect the total ordering properties, thus making this approach a very robust solution for multivariate ordering. However, different marginal components derived from various representations of a colour image will lead to different results of multivariate ordering. Moreover, the output of lexicographical ordering only depends on the first component leading to the followed components taking no effect. To address these issues, three new marginal components are obtained by means of quaternion decomposition, and they are employed by fuzzy lexicographical ordering, and thus a new fuzzy extremum estimation algorithm (FEEA) based on quaternion decomposition is proposed in this study. The novel multivariate mathematical morphological operators are also defined according to FEEA. Comparing with the existing solutions, experimental results show that the proposed FEEA performs better results on multivariate extremum estimation, and the presented multivariate mathematical operators can be easily handled and can provide better results on multivariate image filtering.

This paper presents a novel active contour model for simultaneous segmentation and bias field estimation of medical images. Based on the additive model of images with intensity in homogeneity, we characterize the statistics of image intensities belonging to each different object in local regions as Gaussian distributions with different means and variances. According to maximum a posteriori probability (MAP) and Bayes rule, we first derive a local objective function for image intensities in a neighborhood around each pixel. Then this local objective function is integrated with respect to the neighborhood center over the entire domain to give a global criterion. In a level set formulation, this global criterion defines an energy in terms of the level set functions that represent a partition of the image domain and a bias field that accounts for the intensity in homogeneity of the image. Therefore, image segmentation and bias field estimation are simultaneously achieved via a level set evolution process. Experimental results for synthetic and real images show desirable performances of our method.