本篇介紹了腦部電腦斷層掃描影像和磁振造影影燦之間的對位，藉由腦部電腦斷層與磁振造影影像外緣輪廓清楚的特點，提出了一種基於外緣重心和主軸方法，該方法通過提取影像的外圍輪廊，計算出影像輪廟的重心及主軸，再通過放大、旋轉和平移，使兩幅影像的重心和主軸對齊，進而達到影像對位的目的。此一方法具有計算快速、精確度高的特點，是ᅳ種優良的影像對位方法。

This paper proposes a registration method for computed tomography (CT) and magnetic resonance (MR) brain image. Using the clear outline contours in both CT and MR, a registration method is presented based on centroid and major axis. Size difference, orientation angle and translation offset are calculated to transform the MR brain image to the CT reference image. The almost overlapped outline contour illustrates the proposed processing is promising for CT-MR brain image registration.