摘要
PROPELLER(Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction)磁共振成像方法对刚性运动伪影的消除效果非常显著,已经在头部磁共振成像中获得了成功应用.但是刚性运动一般仅存在于头部成像中,人体其它部位成像往往伴随着不同程度的软组织拉伸变形.对于这种软组织变形必须基于非刚性运动模型才能准确地进行描述并加以校正.本文将PROPELLER采样中的每个k-空间条经过傅立叶逆变换重建得到临时图像,通过基于仿射运动模型的图像配准算法获得非刚性运动信息,然后根据仿射变换的频域性质,对PROPELLER采样中的每个k-空间条进行校正,最后经网格化重建得到最终图像.仿真实验与真实数据实验表明,相对于现有的PROPELLER重建算法,本文所提算法对于刚性运动与仿射运动造成的伪影均具有很好的校正效果.
PROPELLER（Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction） MRI offers an effective means for compensating rigid motion during data collection.So far,this method has been evaluated clinically and found to be able to improve image quality through quantification and correction for head motion,where hypothetically only rotation and translation is present.During imaging of other parts of body,especially in abdomen,soft tissue such as liver,deformation occurs frequently.Traditional PROPELLER reconstruction can′t model this kind of non-rigid body motion and can only attain limited compensation through correlation weighting.In this paper,a new method was proposed for affine motion correction,which extracted affine motion information from image space and compensated it in k-space.The experimental results show that the proposed method could correct artifacts due to not only the rigid motion but also the affine motion.
出处
《电子学报》
EI
CAS
CSCD
北大核心
2010年第4期904-909,共6页
Acta Electronica Sinica
基金
国家973重点基础研究发展规划(No.2010CB732502)
国家自然科学基金(No.30800254
No.30730036)
广东省自然科学基金(No.06301304)
