Diffusion tensor imaging of human skeletal muscle : from simulation to clinical implementation

磁共振弥散成像 体素 纤维束成像 扩散 张量(固有定义) 部分各向异性 计算机科学 各项异性扩散 人工智能 生物医学工程 物理 磁共振成像 数学 医学 几何学 放射科 图像(数学) 热力学
作者
Martijn Froeling
标识
DOI:10.6100/ir737539
摘要

Diffusion tensor imaging (DTI) is a specialized MRI technique that is particularly suited to study muscle structure. Diffusion imaging provides quantitative information on muscle geometry, which is the main mechanical determinant of muscle performance, and on the local histopathological status of muscles to monitor disease progression or the effect of physical exercise or a pharmacological intervention. Diffusion MRI, like all other MRI techniques, is a noninvasive technology that provides a full three dimensional overview of the tissue of interest. It exploits the property that the apparent diffusivity of water is greatest along the dominant muscle fiber direction. In each imaging voxel a diffusion tensor is reconstructed from a series of diffusion-weighted MR images along at least 6 independent diffusion encoding directions. An eigenvalue analysis yields the principal axis of diffusion, which parallels the local muscle fiber orientation. Principal diffusion directions of neighboring voxels are combined for three-dimensional muscle fiber tractography. Most of the information gained by diffusion MRI is unique – in the sense that no alternative procedures exist that deliver similar insights. Diffusion tensor imaging (DTI) and fiber tractography of skeletal muscle is challenging for a number of reasons. First the short T2 relaxation times of muscles result in low SNR, which limits the resolution. Also the EPI readout leads to susceptibility-induced deformations in the images. Furthermore eddy currents and macroscopic motion can lead to a shift of the diffusion weighted volumes with respect to the non-weighted volume. The principal aim of the research described in the thesis was to optimize and standardize DTI data acquisition and processing and explore clinical application of the technique. For this purpose a custom built toolbox for Wolfram Mathematica 8 was developed, containing over 125 functions for simulating, processing, enhancing and analyzing DTI data. To investigate the clinical application of DTI a standardized protocol for acquiring and processing data was developed and tested to measure on various parts of the human body. Five studies were performed. The first study aimed to gain a better understanding of the influence of the sequence parameters, tensor-fitting algorithms, and post processing on image quality and SNR using a combination of simulations and experimentally acquired data. In the second study, reproducibility of the diffusion parameters was assessed. The third study focused on fiber tractography to visualize muscle architecture. In the fourth study DTI was applied to study delayed onset muscle soreness. In the final experimental study, the clinical feasibility of DTI in studies of the female pelvic floor was investigated.

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
大幅提高文件上传限制,最高150M (2024-4-1)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
刚刚
脑洞疼应助鸭梨鸭梨采纳,获得10
1秒前
1秒前
1秒前
专注的书包完成签到,获得积分20
2秒前
3秒前
nienie发布了新的文献求助10
3秒前
3秒前
4秒前
Joey完成签到,获得积分10
4秒前
深情安青应助科研通管家采纳,获得10
4秒前
4秒前
bkagyin应助科研通管家采纳,获得30
4秒前
彳亍1117应助科研通管家采纳,获得10
5秒前
FashionBoy应助科研通管家采纳,获得10
5秒前
5秒前
乐乐应助科研通管家采纳,获得10
5秒前
5秒前
5秒前
领导范儿应助科研通管家采纳,获得10
5秒前
5秒前
我是老大应助科研通管家采纳,获得10
5秒前
英姑应助科研通管家采纳,获得10
5秒前
科目三应助科研通管家采纳,获得10
5秒前
英姑应助科研通管家采纳,获得10
5秒前
fifteen应助科研通管家采纳,获得10
5秒前
5秒前
彳亍1117应助科研通管家采纳,获得10
6秒前
6秒前
YA发布了新的文献求助10
6秒前
搜集达人应助科研通管家采纳,获得10
6秒前
Akim应助和平使命采纳,获得10
6秒前
深情安青应助科研通管家采纳,获得10
6秒前
6秒前
天天快乐应助强健的雅霜采纳,获得10
6秒前
叶子发布了新的文献求助10
7秒前
7秒前
7秒前
活力寻菱发布了新的文献求助10
7秒前
8秒前
高分求助中
The late Devonian Standard Conodont Zonation 2000
Nickel superalloy market size, share, growth, trends, and forecast 2023-2030 2000
The Lali Section: An Excellent Reference Section for Upper - Devonian in South China 1500
Very-high-order BVD Schemes Using β-variable THINC Method 890
Mantiden: Faszinierende Lauerjäger Faszinierende Lauerjäger 800
PraxisRatgeber: Mantiden: Faszinierende Lauerjäger 800
Fundamentals of Dispersed Multiphase Flows 500
热门求助领域 (近24小时)
化学 医学 生物 材料科学 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 基因 遗传学 催化作用 物理化学 免疫学 量子力学 细胞生物学
热门帖子
关注 科研通微信公众号,转发送积分 3258840
求助须知:如何正确求助?哪些是违规求助? 2900579
关于积分的说明 8311432
捐赠科研通 2569844
什么是DOI,文献DOI怎么找? 1396021
科研通“疑难数据库(出版商)”最低求助积分说明 653399
邀请新用户注册赠送积分活动 631319