General Electric Corporate Res. & Dev., Schenectady, NY.
IEEE Trans Med Imaging. 1992;11(3):319-29. doi: 10.1109/42.158935.
A technique for producing geometrically accurate magnetic resonance images (MRIs) with undistorted intensity in the face of high levels of static field inhomogeneity arising from either source is presented. The technique requires the acquisition of two images of the same object with altered gradients. On the basis of a knowledge of these gradients it employs an automatic postprocessing step that exploits some invariant characteristics of the distortions to produce a rectified image from the two acquired images. No phantom imaging is involved and no operator interaction is required. The technique is theoretically justified and compared to other techniques, and experimental results that show that the technique works are presented. The improved accuracy in geometry and intensity may improve reliability of stereotactic surgery, may enhance the feasibility of both clinical and industrial imaging via external fields, and may increase the resolution of microscopic imaging.
提出了一种在面对源自源的高水平静态磁场非均匀性而导致的失真强度的情况下，产生具有几何精度的磁共振图像（MRI）的技术。该技术需要获取同一物体的两个具有不同梯度的图像。基于对这些梯度的了解，它采用了一种自动后处理步骤，利用失真的某些不变特征，从两个获取的图像中生成校正后的图像。不需要进行幻影成像，也不需要操作员进行交互。该技术在理论上是合理的，并与其他技术进行了比较，同时还展示了实验结果，表明该技术是有效的。在几何形状和强度方面的改进精度可以提高立体定向手术的可靠性，可以提高通过外部场进行临床和工业成像的可行性，并可以提高微观成像的分辨率。
