QQ客服 官方微博 反馈留言

题名	斜位电流注入磁共振电阻抗成像的硬件系统设计与实验研究; 斜位电流注入磁共振电阻抗成像的硬件系统设计与实验研究
作者	1巩玉香,电工研究所
学位类别	硕士
答辩日期	2007-06-01
授予单位	中国科学院电工研究所
导师	1杨文晖,电工研究所
关键词	磁共振电阻抗成像 硬件设计 斜位电流注入
其他题名	斜位电流注入磁共振电阻抗成像的硬件系统设计与实验研究
中文摘要	磁共振电阻抗成像（Magnetic Resonance Electrical Impedance Tomography，MREIT）结合了磁共振成像（Magnetic Resonance Imaging，MRI）、电阻抗成像（EIT）两大医学成像技术。由于利用了成像体内部信息，MREIT很大程度上改善了EIT图像。但现在的磁共振电阻抗方法只适合于主磁场平行于水平面的MRI系统（多为超导磁共振系统）。 本文中提出了一种新的斜位电流注入磁共振电阻抗成像方法。该方法不仅适用于主磁场平行于水平面的MRI系统，而且适用于主磁场垂直于水平面的MRI系统。新方法采用16电极电压采集方式，通过四电极向成像体注入三股电流。成像体旋转一次。在对成像要求不高时，亦可以采用两股电流注入模式。 硬件系统实现了以下功能：（1）能够测量注入电流在成像体内部感应磁场的磁感应强度B(x,y,z)，本文利用中国科学院电工所自行开发研制的0.23T永磁磁共振系统来完成这一功能；（2）可以通过电极向成像体注入直流电流，其电流幅值与注入时间即脉冲宽度均可在线调节，可满足各种MREIT成像需求；（3）满足时序匹配要求：实现MRI时序与电流注入的匹配，使得施加电流既能很好的实现相位影响机理又不会影响MRI层选定位精度；（4）配有16路电压通道，可以按照算法对边界电压的要求实现表面电压采集。 设计制作了可拆卸、溶液更换方便的水模和便于更新的电极。以一定比例和浓度的NaCl、CuSO4、Agar混合凝胶体来模拟人体环境，最终得到比较好的实验效果。 Magnetic resonance electrical impedance tomography (MREIT) involves magnetic resonance imaging (MRI) and electrical impedance tomography (EIT), both of which are newly developed in the last few decades. By utilizing the magnetic resonance imaging scanner， MREIT is able to use the interior information of the imaging object. Unfortunately this imaging modality just can be used in specific MRI systems whose main magnetic field is parallel to the horizontal plane. In this paper, a new MREIT method with the currents injected from an oblique plane is proposed. It can not only be used to the permanent MRI scanners but also the superconductive MRI scanners. 16 recessed electrodes are adopted. Two pairs of them are used to inject currents to the imaging object while the others are used to measure the magnitudes of the surface voltages. If three currents are injected, the imaged object will be rotated once. If two injection currents are enough, rotation is not necessary. As for the hardware, it is expected to realize the following functions: (1) Measuring the magnetic flux density B(x, y, z) generated by the injection currents. This hardware system is based on the 0.23T MRI scanner, developed by Institute of Electrical Engineering, Chinese Academy of Sciences .The direction of its main magnetic field is perpendicular to horizontal plane (2) Injecting currents to the imaging object. Steady and big enough currents are needed. Here the amplitude and injection time of the currents are adjusted on-line (3) Making the sequences matching each other perfectly. So the injection currents are able to perform their affections on phase and don’t affect the slice-selection (4) Measuring the magnitudes of surface voltages. A special phantom and electrodes are produced. The phantom is take-down and easy to change the solution. Electrodes are also take-down, so that it is convenient to renew them. Using the device, good result is got.
语种	中文
公开日期	2010-10-18
页码	65
分类号	TM1
内容类型	学位论文
源URL	[http://ir.iee.ac.cn/handle/311042/7007]
专题	电工研究所_其他部门_其他部门_硕士学位论文
推荐引用方式 GB/T 7714	1巩玉香,电工研究所. 斜位电流注入磁共振电阻抗成像的硬件系统设计与实验研究, 斜位电流注入磁共振电阻抗成像的硬件系统设计与实验研究[D]. 中国科学院电工研究所. 2007.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。