Moser E, Holzmueller P, Gomiscek G
Institut fuer Medizinische Physik, Universitaet Wien, Austria.
Magn Reson Med. 1992 Apr;24(2):213-20. doi: 10.1002/mrm.1910240203.
The extraction of reliable and useful relaxation time data for tissue characterization by NMR requires strict protocols, optimized for each type of biological tissue, which include parameters like storage duration and temperature as well as measurement parameters. Spin-lattice relaxation times in liver tissue vary not only with NMR frequency but also with their "time-after-excision characteristics," while spin-spin relaxation times are almost independent of most parameters which influence T1 at 20 MHz in normal liver tissue (e.g., species, sex, circadian rythm, starvation). T2, however, being more sensitive to water content and pH changes, is well suited for detecting nonspecific tissue alterations (e.g., due to ischemia, chemical toxins). Following the suggestions outlined herein, investigation of at least 120 min of time-after-excision (storage) effects allows the significant distinguishing of various physiological differences in normal liver tissue as well as improvement of early detection of liver pathologies.
通过核磁共振（NMR）获取用于组织表征的可靠且有用的弛豫时间数据，需要针对每种生物组织进行优化的严格方案，这些方案包括储存时长、温度等参数以及测量参数。肝脏组织中的自旋 - 晶格弛豫时间不仅随NMR频率变化，还随其“切除后时间特性”变化，而在正常肝脏组织中，自旋 - 自旋弛豫时间几乎不受大多数在20 MHz时影响T1的参数（如物种、性别、昼夜节律、饥饿）的影响。然而，T2对含水量和pH变化更敏感，非常适合检测非特异性组织改变（如由于局部缺血、化学毒素引起的改变）。按照本文所述的建议，对至少120分钟的切除后（储存）效应进行研究，能够显著区分正常肝脏组织中的各种生理差异，并改善肝脏病变的早期检测。
