Brain Nerve Fiber Tracking Algorithm Based on Improved Optical Flow in Combination of Bayesian Prior Constraints

2020 ◽  
Vol 10 (2) ◽  
pp. 452-457
Author(s):  
Shen Jian ◽  
Chen Huan ◽  
Zuo Jianjian ◽  
Pan Xuming

Diffusion Tensor Magnetic Resonance Imaging (DT-MRI) can track the brain nerve fiber and reconstruct non-invasively the three-dimensional image by tracing the local tensor orientation. The commonly used tracking method is usually based on the local diffusion information and insufficient to consider the geometrical structure and fractional anisotropy which is constrained by anatomical structure and physiological function of human. Therefore, a novel brain nerve fiber tracking algorithm based on Bayesian optical-flow constrained framework is proposed. The construction of energy function is the core step of global optical flow field estimation technology. In this paper, data fidelity constraint, prior constraint, penalty function and weight factor are introduced to construct Bayesian constraint function. The fiber trend model is displayed intuitively to obtain the structure and direction of the inner nerve fibers of the brain, which can better assist in the diagnosis and treatment of clinical brain diseases, and lay a foundation for subsequent brain tissue research.

2019 ◽  
Vol 14 (01) ◽  
pp. e16-e23
Author(s):  
Niyazi Acer ◽  
Mehmet Turgut

Background Brachial plexus (BP) is composed of intercommunications among the ventral roots of the nerves C5, C6, C7, C8, and T1 in the neck. The in vivo and in vitro evaluation of axons of the peripheral nervous system is performed using different techniques. Recently, many studies describing the application of fiber tractography and stereological axon number estimation to peripheral nerves have been published. Methods Various quantitative parameters of nerve fibers, including axon number, density, axonal area, and myelin thickness, can be estimated using stereological techniques. In vivo three-dimensional reconstruction of axons of BP can be visualized using a combined technique of diffusion tensor imaging (DTI) and fiber tracking with the potential to evaluate nerve fiber content. Conclusion It is concluded that terminal branches of BP can be successfully visualized using DTI, which is a highly reproducible method for the evaluation of BP as it shows anatomical and functional features of neural structures. We believe that quantitative morphological findings obtained from BP will be useful for new experimental, developmental, and pathological studies in the future.


2017 ◽  
Vol 24 (2) ◽  
pp. 482-489 ◽  
Author(s):  
Jianzhong Hu ◽  
Ping Li ◽  
Xianzhen Yin ◽  
Tianding Wu ◽  
Yong Cao ◽  
...  

The spinal cord is the primary neurological link between the brain and other parts of the body, but unlike those of the brain, advances in spinal cord imaging have been challenged by the more complicated and inhomogeneous anatomy of the spine. Fortunately with the advancement of high technology, phase-contrast synchrotron radiation microtomography has become widespread in scientific research because of its ability to generate high-quality and high-resolution images. In this study, this method has been employed for nondestructive imaging of the internal microstructure of rat spinal cord. Furthermore, digital virtual slices based on phase-contrast synchrotron radiation were compared with conventional histological sections. The three-dimensional internal microstructure of the intramedullary arteries and nerve fibers was vividly detected within the same spinal cord specimen without the application of a stain or contrast agent or sectioning. With the aid of image post-processing, an optimization of vessel and nerve fiber images was obtained. The findings indicated that phase-contrast synchrotron radiation microtomography is unique in the field of three-dimensional imaging and sets novel standards for pathophysiological investigations in various neurovascular diseases.


2021 ◽  
Vol 15 ◽  
Author(s):  
Miriam Menzel ◽  
Marouan Ritzkowski ◽  
Jan A. Reuter ◽  
David Gräßel ◽  
Katrin Amunts ◽  
...  

The correct reconstruction of individual (crossing) nerve fibers is a prerequisite when constructing a detailed network model of the brain. The recently developed technique Scattered Light Imaging (SLI) allows the reconstruction of crossing nerve fiber pathways in whole brain tissue samples with micrometer resolution: the individual fiber orientations are determined by illuminating unstained histological brain sections from different directions, measuring the transmitted scattered light under normal incidence, and studying the light intensity profiles of each pixel in the resulting image series. So far, SLI measurements were performed with a fixed polar angle of illumination and a small number of illumination directions, providing only an estimate of the nerve fiber directions and limited information about the underlying tissue structure. Here, we use a display with individually controllable light-emitting diodes to measure the full distribution of scattered light behind the sample (scattering pattern) for each image pixel at once, enabling scatterometry measurements of whole brain tissue samples. We compare our results to coherent Fourier scatterometry (raster-scanning the sample with a non-focused laser beam) and previous SLI measurements with fixed polar angle of illumination, using sections from a vervet monkey brain and human optic tracts. Finally, we present SLI scatterometry measurements of a human brain section with 3 μm in-plane resolution, demonstrating that the technique is a powerful approach to gain new insights into the nerve fiber architecture of the human brain.


2006 ◽  
Author(s):  
F. Prados ◽  
A. Bardera ◽  
M. Sbert ◽  
I. Boada ◽  
M. Feixas

2003 ◽  
Vol 16 (2_suppl_part2) ◽  
pp. 156-160
Author(s):  
Pia C. Sundgren ◽  
Qian Dong ◽  
Robert Welsh

1969 ◽  
Vol 43 (3) ◽  
pp. 480-505 ◽  
Author(s):  
J. Metuzals

High-resolution electron microscopy is integrated with physicochemical methods in order to investigate the following preparations of the giant nerve fibers of the squid (Loligo pealii L.): (1) Thin sections of fibers fixed in four different fixatives; (2) fresh axoplasm stained negatively in solutions of different pH and composition; (3) chemically isolated threadlike elements of the axoplasm. A continuous, three-dimensional network can be identified in all these preparations of the axoplasm. The network is composed of coiled or looped unit-filaments ∼30 A wide. The unit-filaments are intercoiled in strands ∼ 70–250 A wide. The strands are oriented longitudinally in the axoplasm, often having a sinuous course and cross-associations. Microtubules are surrounded by intercoiled unit-filaments and filamentous strands. Calcium ions cause loosening and disintegration of the network configuration. UO2++ ions of a 1% uranyl acetate solution at pH 4.4 display a specific affinity for filamentous protein structures of the squid giant nerve fiber axoplasm, segregating the filamentous elements of the axoplasm in a coiled, threadlike preparation. The uranyl ions combine probably with the carboxyl groups of the main amino acids of the protein—glutamic and aspartic acids. It is proposed that by coiling/decoiling and folding/unfolding of the unit-filaments, shifts in physicochemical properties of the axoplasm are maintained.


2017 ◽  
Vol 10 (05) ◽  
pp. 1743006 ◽  
Author(s):  
Sa Liu ◽  
Jun Nie ◽  
Yusha Li ◽  
Tingting Yu ◽  
Dan Zhu ◽  
...  

We present a three-dimensional (3D) isotropic imaging of mouse brain using light-sheet fluorescent microscopy (LSFM) in conjunction with a multi-view imaging computation. Unlike common single view LSFM is used for mouse brain imaging, the brain tissue is 3D imaged under eight views in our study, by a home-built selective plane illumination microscopy (SPIM). An output image containing complete structural information as well as significantly improved resolution ([Formula: see text]4 times) are then computed based on these eight views of data, using a bead-guided multi-view registration and deconvolution. With superior imaging quality, the astrocyte and pyramidal neurons together with their subcellular nerve fibers can be clearly visualized and segmented. With further including other computational methods, this study can be potentially scaled up to map the connectome of whole mouse brain with a simple light-sheet microscope.


2021 ◽  
Vol 9 ◽  
Author(s):  
Scott A. Holmes ◽  
Anastasia Karapanagou ◽  
Steven J. Staffa ◽  
David Zurakowski ◽  
Ronald Borra ◽  
...  

Acute peripheral nerve injury can lead to chronic neuropathic pain. Having a standardized, non-invasive method to evaluate pathological changes in a nerve following nerve injury would help with diagnostic and therapeutic assessments or interventions. The accurate evaluation of nerve fiber integrity after injury may provide insight into the extent of pathology and a patient's level of self-reported pain. The aim of this investigation was to evaluate the extent to which peripheral nerve integrity could be evaluated in an acute ankle injury cohort and how markers of nerve fiber integrity correlate with self-reported pain levels in afferent nerves. We recruited 39 pediatric participants with clinically defined neuropathic pain within 3 months of an ankle injury and 16 healthy controls. Participants underwent peripheral nerve MRI using diffusion tensor (DTI) and magnetization transfer imaging (MTI) of their injured and non-injured ankles. The imaging window was focused on the branching point of the sciatic nerve into the tibial and fibular division. Each participant completed the Pain Detection Questionnaire (PDQ). Findings demonstrated group differences in DTI and MTI in the sciatic, tibial and fibular nerve in the injured ankle relative to healthy control and contralateral non-injured nerve fibers. Only AD and RD from the injured fibular nerve correlated with PDQ scores which coincides with the inversion-dominant nature of this particular ankle injuruy cohort. Exploratory analyses highlight the potential remodeling stages of nerve injury from neuropathic pain. Future research should emphasize sub-acute time frames of injury to capture post-injury inflammation and nerve fiber recovery.


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