Water content and water structure in CT and MR signal changes: possible influence in detection of early stroke.
Water content and water structure in CT and MR signal changes: possible influence in detection of early stroke.
复制标题
CT 和 MR 信号中的水含量和水结构变化：可能影响早期中风的检测。
DOI：
--
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Mohktar Gad0
中科院分区：
文献类型：
--
作者：
Evan Unger1;James Littlefield;Mohktar Gad0
作者和其他人最近的工作表明，在检测急性卒中方面，MR成像比CT更敏感。为了分离水含量和水结构对MR信号强度的影响，我们进行了两组实验，使用简单的模型系统：水含量增加的明胶凝胶和硬化的鸡蛋。对两种系统进行了CT和MR检查。在CT上，CT衰减（Hounsfield单位）和明胶凝胶的比重之间存在直接的线性关系，并且与水含量成反比。随着硬化，鸡蛋样品的比重只有很小的变化，并且正如CT上所预期的那样，伴随硬化的线性衰减没有变化。在MR上，明胶凝胶中的水含量与自旋-晶格（T1）弛豫时间（r = 0.92，p小于0.01）和自旋-自旋（T2）弛豫时间（r = 0.91，p小于0.05）之间存在线性关系。然而，这些变化不足以解释脑梗死后信号强度的变化。鸡蛋的简单细胞系统表明，T1和T2的缩短伴随着鸡蛋硬化，而水含量的变化最小;水从散装水到结合或结构形式的转变可能是这种现象的基础。我们发现，水的结构，而不仅仅是水含量是一个重要的机制弛豫时间的变化和信号强度的变化，在急性中风。
Recent work by the authors and others has shown that MR imaging is more sensitive than CT in the detection of acute stroke. To separate the effects of water content and water structure on MR signal intensity, we undertook two sets of experiments that used simple model systems: gelatin gels with increasing water content and hardened hens' eggs. CT and MR were performed on both systems. On CT there was a direct linear relationship between CT attenuation (Hounsfield units) and the specific gravity of the gelatin gels, and an inverse relationship with water content. There was only a minimal change in the specific gravity of egg samples with hardening and, as expected on CT, no change in linear attenuation accompanying hardening. On MR there was a linear relationship between water content in gelatin gels and spin-lattice (T1) relaxation time (r = .92, p less than .01) and spin-spin (T2) relaxation time (r = .91, p less than .05). However, these changes were insufficient to explain the changes of signal intensity that occur in the brain with infarction. The simple cellular system with hens' eggs demonstrated that shortening of T1 and T2 accompanied egg hardening with minimal change in water content; the shift of water from bulk water to a bound or structured form was probably the basis of this phenomenon. We found that water structure and not merely water content is a significant mechanism underlying relaxation time changes and signal intensity changes in acute stroke.
脑异常：使用计算的 T1 和 T2 磁共振图像进行诊断。
影响因子：
19.7
作者：
Mills,CM;Crooks,LE;Kaufman,L;Brant-Zawadzki,M
通讯作者：
Brant-Zawadzki,M
急性实验性脑缺血的质子核磁共振成像。
影响因子：
6.7
作者：
Mano,I;Levy,RM;Crooks,LE;Hosobuchi,Y
通讯作者：
Hosobuchi,Y