Viard Romain, Betrouni Nacim, Vermandel Maximilien, Mordon Serge, Rousseau Jean, Vanhoutte M
INSERM U703, Lille, France.
Annu Int Conf IEEE Eng Med Biol Soc. 2008;2008:3649-52. doi: 10.1109/IEMBS.2008.4649998.
In this paper, we present a method to characterize and correct geometric image distortion in 0.2 T MR images. A large 3D phantom with spherical balls was used to characterize geometric distortion on an AIRIS Mate 0.2 T MR Scanner (Hitachi). MR images of the phantom were acquired in axial, sagittal and coronal planes using 2D Fast Spin Echo (FSE) sequence and distortions were measured at each control point. Two piecewise interpolation methods were then applied to correct geometric distortion. Distortion was characterized and corrected in any axial, sagittal or coronal slice within an effective FOV of 330(LR) x 180(AP) x 210(HF) mm(3). The distortion was reduced from 16 mm to 1.2 mm at 180 mm from the magnet center. A fast and accurate method for correction of geometric distortion was performed within large distances from the magnet isocenter.
在本文中，我们提出了一种用于表征和校正0.2 T磁共振（MR）图像中几何图像失真的方法。使用一个带有球形球的大型3D体模在AIRIS Mate 0.2 T MR扫描仪（日立公司）上表征几何失真。使用二维快速自旋回波（FSE）序列在轴向、矢状面和冠状面获取体模的MR图像，并在每个控制点测量失真。然后应用两种分段插值方法来校正几何失真。在330（左右）×180（前后）×210（上下）mm³的有效视野内的任何轴向、矢状面或冠状切片中表征并校正失真。在距磁体中心180 mm处，失真从16 mm减小到1.2 mm。在距磁体等中心较大距离范围内执行了一种快速且准确的几何失真校正方法。
