Soher Brian J, Dale Brian M, Merkle Elmar M
Center for Advanced MR Development, Duke University Medical Center, Box 3808, Durham, NC 27710, USA.
Magn Reson Imaging Clin N Am. 2007 Aug;15(3):277-90, v. doi: 10.1016/j.mric.2007.06.002.
This article illustrates changes in the underlying physics concepts related to increasing the main magnetic field from 1.5T to 3T. The effects of these changes on tissue constants and practical hardware limitations is discussed as they affect scan time, quality, and contrast. Changes in susceptibility artifacts, chemical shift artifacts, and dielectric effects as a result of the increased field strength are also illustrated. Based on these fundamental considerations, an overall understanding of the benefits and constraints of signal-to-noise ratio and contrast-to-noise ratio changes between 1.5T and 3T MR systems is developed.
本文阐述了与将主磁场从1.5T提高到3T相关的基础物理概念的变化。讨论了这些变化对组织常数和实际硬件限制的影响，因为它们会影响扫描时间、质量和对比度。还说明了由于场强增加而导致的磁化率伪影、化学位移伪影和介电效应的变化。基于这些基本考虑因素，形成了对1.5T和3T磁共振系统之间信噪比和对比噪声比变化的益处和限制的全面理解。
