Kochunov Peter, Lancaster Jack L, Glahn David C, Purdy David, Laird Angela R, Gao Feng, Fox Peter
Research Imaging Center, University of Texas Health Science Center at San Antonio, Texas, USA.
Hum Brain Mapp. 2006 Dec;27(12):957-62. doi: 10.1002/hbm.20235.
Modern computational brain morphology methods require that anatomical images be acquired at high resolution and with a high signal-to-noise ratio. This often translates into long acquisition times (>20 minutes) and images susceptible to head motion. In this study we tested retrospective motion correction (RMC), common for functional MRI (fMRI) and PET image motion correction, as a means to improve the quality of high-resolution 3-D anatomical MR images. RMC methods are known to be effective for correcting interscan motion; therefore, a single high-resolution 3-D MRI brain study was divided into six shorter acquisition segments to help shift intrascan motion into interscan motion. To help reduce intrascan head motion, each segment image was reviewed for motion artifacts and repeated if necessary. Interscan motion correction was done by spatially registering images to the third image and forming a single average motion-corrected image. RMC was tested on 35 subjects who were considered at high risk for head motion. Our results show that RMC provided better contrast-to-noise ratio and boundary detail when compared to nonmotion-corrected averaged images.
现代计算脑形态学方法要求以高分辨率和高信噪比采集解剖图像。这通常意味着采集时间较长（>20分钟），且图像容易受到头部运动的影响。在本研究中，我们测试了回顾性运动校正（RMC），这在功能磁共振成像（fMRI）和正电子发射断层显像（PET）图像运动校正中很常见，作为提高高分辨率三维解剖磁共振图像质量的一种方法。已知RMC方法对于校正扫描间运动是有效的；因此，将一项单一的高分辨率三维磁共振脑研究分为六个较短的采集段，以帮助将扫描内运动转化为扫描间运动。为了帮助减少扫描内头部运动，对每个段图像进行运动伪影检查，并在必要时重复采集。通过将图像与第三幅图像进行空间配准并形成单个平均运动校正图像来进行扫描间运动校正。对35名被认为头部运动风险较高的受试者进行了RMC测试。我们的结果表明，与未进行运动校正的平均图像相比，RMC提供了更好的对比度噪声比和边界细节。
