基于正则化的磁共振相控阵线圈图像均匀性校正算法  

Regularized Inhomogeneity Correction Method for Phased Array Image in Magnetic Resonance Imaging

作　　者：郭红宇[1,2] 裴晓敏[1] 罗维涛[1] 戴建平[3] 

机构地区：[1]沈阳工业大学电气工程学院,沈阳110023 [2]东北大学中荷生物医学工程学院,沈阳110004 [3]北京天坛医院,北京100050

出　　处：《生物医学工程学杂志》2011年第5期922-926,931,共6页Journal of Biomedical Engineering

基　　金：国家自然科学基金资助项目(50877008)

摘　　要：由于能提供更大的扫描视野,更高的信噪比和缩短扫描时间,相控阵线圈已经被广泛使用在磁共振成像(MRI)设备中。相控阵线圈的图像重建合成最常用的是SOS算法,但是SOS算法通常会造成图像的灰度不均匀。这样不仅会直接影响医生诊断的准确性,同时对图像自动分割等后处理技术的使用也会产生不良影响。本文提出一种改进的基于正则化的最小二乘化方法,用于MRI相控阵图像的合成。在该方法中利用均匀的大体线圈和相控阵线圈进行预扫描获得线圈敏感图,通过引入正则函数来控制重建图像的噪声。此外,在正则函数中还使用大体线圈的预扫描图像作为参考图像。使用水模和志愿者成像数据验证,该方法能够有效提高相控阵线圈重建图像的均匀性。Phased array coils （multiple receiver coil systems） have been extensively used for acquisition of MR images owing to their ability of increasing SNR, extending field-of-view （FOV）, and reducing acquisition time. But the SOS algorithm, which is main method for phased array image reconstruction, will cause inhomogeneity in reconstructed im- age. A regularized least square method for phased array image combination is proposed in this paper. In the method, an additional reference scan is performed in advance. By using the reference scan, coil sensitivity map can be acquired, and image reconstructed from reference scan can be used as reference data in the regulation term. Experiments showed that the image uniformity was greatly improved by this method with scanning phantom and volunteer.

关 键 词：均匀性 相控阵线圈 正则化 重建 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]