Ordidge R J, Gibbs P, Chapman B, Stehling M K, Mansfield P
Department of Physics, University of Nottingham, United Kingdom.
Magn Reson Med. 1990 Nov;16(2):238-45. doi: 10.1002/mrm.1910160205.
Tissue contrast in MR images is a strong function of spin-lattice (T1) and spin-spin (T2) relaxation times. However, the T1 relaxation time is rarely quantified because of the long scan time required to produce an accurate T1 map of the subject. In a standard 2D FT technique, this procedure may take up to 30 min. Modifications of the echo-planar imaging (EPI) technique which incorporate the principle of inversion recovery (IR) enable multislice T1 maps to be produced in total scan times varying from a few seconds up to a minute. Using IR-EPI, rapid quantification of T1 values may thus lead to better discrimination between tissue types in an acceptable scan time.
磁共振图像中的组织对比度是自旋晶格(T1)和自旋-自旋(T2)弛豫时间的强函数。然而,由于生成受试者准确T1图谱所需的扫描时间长,T1弛豫时间很少被量化。在标准的二维傅里叶变换(2D FT)技术中,这个过程可能需要长达30分钟。结合反转恢复(IR)原理的回波平面成像(EPI)技术的改进,能够在从几秒到一分钟不等的总扫描时间内生成多层T1图谱。因此,使用IR-EPI快速量化T1值可能会在可接受的扫描时间内更好地区分组织类型。