小动物高分辨扩散加权成像在临床MRI上的实现

波谱学杂志 ›› 2012, Vol. 29 ›› Issue (3): 372-378.

小动物高分辨扩散加权成像在临床MRI上的实现

王前锋¹，李建奇^1*，吴东梅¹，王小楼²，贾杰²，张敏¹，李鲠颖¹

1. 上海市磁共振重点实验室，华东师范大学物理系，上海 200062； 
2. 复旦大学附属华山医院，康复科，上海 200040

收稿日期:2011-11-23 修回日期:2011-12-31 出版日期:2012-09-05 在线发表日期:2012-09-05
通讯作者: 李建奇,jqli@phy.ecnu.edu.cn E-mail:jqli@phy.ecnu.edu.cn
基金资助:
上海市科委基础研究重点资助项目(10JC1414600).

High-Resolution Diffusion-Weighted Imaging on Small Animals on a Clinical 3 T MRI Scanner

WANG Qian-Feng¹, LI Jian-Qi^1*, WU Dong-Mei¹, WANG Xiao-Lou², JIA Jie², ZHANG Min¹, LI Geng-Ying¹ 

1. Shanghai Key Laboratory of Magnetic Resonance Imaging, Department of Physics, East China Normal University, Shanghai 200062, China;
2. Department of Rehabilitation, Huashan Hospital, Fudan University, Shanghai 200040, China

Received:2011-11-23 Revised:2011-12-31 Published:2012-09-05 Online:2012-09-05
Contact: LI Jian-Qi,jqli@phy.ecnu.edu.cn E-mail:jqli@phy.ecnu.edu.cn
Supported by:
上海市科委基础研究重点资助项目(10JC1414600).

摘要/Abstract

摘要：

在临床用MRI系统上对小动物扩散加权成像一般采用回波平面成像序列，但是回波平面成像易受偏共振效应的影响，得到的图像伪影大、几何变形严重、图像分辨率低，无法探究微小的生物组织结构. 该文报道了在临床用3 T MRI系统上采用自旋回波序列实现了高分辨扩散加权成像. 为减少运动伪影，序列中整合了导航回波矫正技术. 对脑缺血模型大鼠脑部的扫描结果显示，自旋回波扩散加权序列获得的图像基本没有发生形变，并且具有较高的分辨率和较好的信噪比.

关键词: 磁共振成像(MRI), 扩散加权成像, 导航回波, 高分辨, 小动物

Abstract:

The most commonly used pulse sequence for small animal diffusion-weighted imaging on clinical MRI scanners is the single shot echo planar imaging (EPI) sequence. However, EPI is susceptible to off-resonance artifacts arising from the inhomogeneity of main field, local susceptibility gradients, and chemical shift, leading to image quality degradation. In this study, we implemented a high-resolution spinecho diffusion weighted imaging (SE-DWI) on a clinical 3 T MRI scanner. To reduce the motion artifacts, navigator echoes were acquired to correct the phase errors. The results from ischemic rat brain demonstrated that SE-DWI was feasible for imaging small animals on 3 T clinical MRI scanners.

Key words: MRI, diffusion-weighted imaging, navigator echo, high resolution, small animal

中图分类号:

O482.53

王前锋, 李建奇, 吴东梅, 王小楼, 贾杰, 张敏, 李鲠颖. 小动物高分辨扩散加权成像在临床MRI上的实现[J]. 波谱学杂志, 2012, 29(3): 372-378.

WANG Qian-Feng, LI Jian-Qi, WU Dong-Mei, WANG Xiao-Lou, JIA Jie, ZHANG Min, LI Geng-Ying . High-Resolution Diffusion-Weighted Imaging on Small Animals on a Clinical 3 T MRI Scanner[J]. Chinese Journal of Magnetic Resonance, 2012, 29(3): 372-378.

参考文献

[1] Mac Donald C L，Dikranian K，Bayly P，et al. Diffusion tensor imaging reliably detects experimental traumatic axonal injury and indicates approximate time of injury[J]. J Neurosci，2007，27(44): 11 869-11 876. 

[2] Sotak C H. The role of diffusion tensor imaging in the evaluation of ischemia brain injury——a review[J]. NMR Biomed，2002，15(7): 561-569. 

[3] Karaarslan E，Arslan A. Diffusion weighted MR imaging in non-infarct lesions of the brain[J]. Eur J Radiol，2008，65(3): 402-416. 

[4] Del Sette M，Dinia L，Bonzano L，et al. White matter lesions in migraine and right-to-left shunt: a conventional and diffusion MRI study
[J]. Cephalalgia，2008，28(4): 376-382. 

[5] Maier S E，Sun Y，Mulkern R V. Diffusion imaging of brain tumors[J]. NMR Biomed，2010，23(7): 849-864. 

[6] Charles-Edwards E M，deSouza N M. Diffusion-weighted magnetic resonance imaging and its application to cancer[J]. Cancer Imaging， 2006，6(1): 135-143. 

[7] Mac Donald C L，Dikranian K，Song S K，et al. Detection of traumatic axonal injury with diffusion tensor imaging in a mouse model of traumatic brain injury[J]. Exp Neurol，2007，205(1): 116-131. 

[8] Van de Looij Y，Mauconduit F，Beaumont M，et al. Diffusion tensor imaging of diffuse axonal injury in a rat brain trauma model[J]. NMR Biomed，2012, 25(1): 93-103.

[9] Song S K，Kim J H，Lin S J，et al. Diffusion tensor imaging detects age-dependent white matter changes in a transgenic mouse model with amyloid deposition[J]. Neurobiol Dis，2004，15(3): 640-647. 

[10] Song S K，Yoshino J，Le T Q，et al. Demyelination increases radial diffusivity in corpus callosum of mouse brain[J]. NeuroImage， 2005，26(1): 32-40. 

[11] Jiang Y，Johnson G A. Microscopic diffusion tensor imaging of the mouse brain[J]. NeuroImage，2010，50(2): 465-471. 

[12] Mayer D，Zahr N M，Adalsteinsson E，et al. In vivo fiber tracking in the rat brain on a clinical 3T MRI system using a high strength insert gradient coil[J]. NeuroImage，2007，35(3): 1 077-1 085. 

[13] Bammer R. Basic principles of diffusion weighted imaging[J]. Eur J Radiol，2003，45(3): 169-184. 

[14] Koh D M，Collins D J. Diffusion-weighted MRI in the body: applications and challenges in oncology[J]. Am J Roentgenol，2007，188(6): 1 622-1 635. 

[15] Roberts T P，Schwartz E S. Principles and implementation of diffusion-weighted and diffusion tensor imaging[J]. Pediatr Radiol， 2007，37(8): 739-748. 

[16] Mcnab J A，Miller K L. Steady-state diffusion-weighted imaging:theory，acquisition and analysisy[J]. NMR Biomed，2010，23(7): 781-793. 

[17] Schick F，Forster J，Machann J，et al. Improved clinical echo-planar MRI using spatial-spectral excitation[J]. Magn Reson Imaging， 1998，8(4): 960-967. 

[18] Yang Q X，Wang J L，Smith M B. et al. Reduction of magnetic field inhomogeneity artifacts in echo planar imaging with SENSE and GESEPI at high field[J]. Magn Reson Med，2004，52(6): 1 418-1 423. 

[19] Stejskal E O，Tanner J E. Spin diffusion measurements: spin echoes in the presence of a time-dependent field gradient[J]. J Chem Phys，1965，42(1): 288-292. 

[20] Jiang Xiao-ping(姜小平)，Li Jian-qi(李建奇)，Fan Ming-xia(范明霞)，et al. Line-scan diffusion tensor imaging on low field strenth MRI scanner. (低场MRI系统中线扫描扩散张量成像方法的研究)[J]. Chinese J Magn Reson(波谱学杂志) ，2008，25(4): 470-477. 

[21] Mori S，Van Zijl P C. A motion correction scheme by twin-echo navigation for diffusion-weighted magnetic resonance imaging with multiple RF echo acquisition[J]. Magn Reson Med，1998，40(4): 511-516. 

[22] Wang Y，Grimm R C，Felmlee J P，et al. Algorithms for extracting motion information from navigator echoes[J]. Magn Reson Med， 1996，36(1): 117-123. 

[23] Miller K L， Pauly J M. Nonlinear phase correction for navigated diffusion imaging[J]. Magn Reson Med，2003，50(2): 343-353 . 

[24] Chen Wei-bo(陈伟波)，Li Jian-qi(李建奇)，Jiang Xiao-ping(姜小平)，et al. Implementation of self-navigated motion correction fast spin echo technique at low field MRI system(自导航快速自旋回波在低场MRI上的实现)[J]. Chinese J Magn Reson(波谱学杂志) ，2009，26(2): 197-205. 

[25] Anderson A W，Gore J G. Analysis and correction of motion artifacts in diffusion-weighted imaging[J]. Magn Reson Med，1994，32(2): 379-387. 

[26] Mori S，Barker P B. Diffusion magnetic resonance imaging:its principle and applications[J]. Anat Rec，1999，257(3): 102-109. 

[27] Liu K F，Li F H，Tatlisumak T，et al. Regional variations in the apparent diffusion coefficient and the intracellular distribution of water in rat brain during Acute focal ischemia[J]. Stroke，2001，32(8): 1 899-1 905. 

[28 ] Chen F，De Keyzer F，Wang H J，et al. Diffusion weighted imaging in small rodents using clinical MRI scanners[J]. Methods， 2007，43(1): 12-20.