一.场强概述 磁共振(magnetic resonance imaging,MRI)设备中磁体是其核心部件及组成部分,它的主要作用是提供一个稳定的、均匀的空间磁场环境。这个空间磁场我们用静磁场B0来表示,其磁场强度大小简称场强(field strength)。 为什么静磁场用B0来表示呢?因为一般静磁场是不变的(在理想情况下,假设磁体在有效孔径中磁场均匀...
1.磁场强度(Magnetic Field Strength): -衡量MRI设备的主磁场的强度,通常以特斯拉(Tesla,T)为单位。常见的MRI设备磁场强度包括1.5T和3T。 2.脉冲重复时间(Repetition Time,TR): - TR是指两个连续脉冲之间的时间间隔。它影响图像的对比度和组织鉴别度。短TR通常用于增强脂肪和长TR用于增强水。 3.回波时间(Echo ...
Collins CM, Smith MB. Signal-to-noise ratio and absorbed power asfunctions of main magnetic field strength, and definition of “90 degrees” RF pulse for the head in the birdcage coil [J].Magn Reson Med, 2001; 45: 684–691. Pohmann R, Speck...
[3] ROHRERM, BAUER H, MINTOROVITCH J, et al. Comparison of magnetic properties of MRI contrastmedia solutions at different magnetic field strengths [J]. Investigativeradiology, 2005, 40(11): 715-24. [4] Noebauer-HuhmannIM, Szomolanyi P, Juras V, Kraff O, Ladd ME, Trattnig S. Gado...
Diffusion MRIMachine learning (CNN)Diffusion MRI (dMRI) data is increasingly being acquired on multiple scanners as part of large multi-center neuroimaging studies. However, diffusion imaging is particularly sensitive to...doi:10.1007/978-3-030-00931-1_14Suheyla Cetin Karayumak...
Image Acquisition 影像采集 Gradient Field 梯度场 Image Acquisition Time 影像采集时间 Gradient Increment 梯度增量 Image Contrast 影像对比度 Gradient Pusle 梯度脉冲 laminar flow 层流 Gradient Recalled Acquisition in Steady State、GRAS 稳态梯度回波采集 Imaging S...
As expected, the distortions were also greater at higher field strengths. The results in human subject paralleled the findings in the phantom study. 展开 关键词: Magnetic resonance imaging Susceptibility artifacts Magnetic field strength Paranasal sinuses ...
T (2006) Line scan diffusion tensor MRI at low magnetic field strength: feasibility study of cervical spondylotic myelopathy in an early clinical stage. J... Katiraei, S,Haghighat, M,Bazmi, N,... - 《Journal of Family & Reproductive Health》 被引量: 47发表: 2010年 Diffusion tensor imagin...
As lightweight magnets must be used, the magnetic field strengths of portable devices are generally lower than 1 T, commonly referred to as low-field devices. The spatial resolution of such devices can range from ~ 100 μm [10, 12] to a couple of millimeters [13], while the ...
T1 and T2 of frog muscle as a function of magnetic field strength (modified from original). Advanced Discussion (show/hide)» References Bottomley PA, Foster TH, Argersinger RE, Pfeifer LM.A review of normal tissue hydrogen relaxation times and relaxation mechanisms from 1-100 MHz: dependence...