在Carr-Purcell-Meiboom-Gill（CPMG）测量中生物组织横向弛豫时间T2对脉冲间隔时间的依赖性。

Dependence of transverse relaxation time T2 of biologic tissues on the interpulse delay time in Carr-Purcell-Meiboom-Gill (CPMG) measurements.

作者信息

Shioya S, Kurita D, Haida M, Fukuzaki M, Tanigaki T, Kutsuzawa T, Ohta Y

机构信息

Department of Internal Medicine, Tokai University School of Medicine, Kanagawa, Japan.

出版信息

Tokai J Exp Clin Med. 1997 May;22(2):27-31.

PMID:9608628

Abstract

To determine the transverse relaxation time (T2) of biological tissues in nuclear magnetic resonance measurements, the Carr-Purcell-Meiboom-Gill (CPMG) method has been recommended to avoid the effect of external magnetic field inhomogeneity on T2 values. However, a dependence of T2 on the interpulse delay time (IPDT) in the CPMG measurements has been shown for biological tissues. The present study examined the dependence of the T2 on IPDT for muscle, lung (passively collapsed or degassed), and brain tissues. It was found that the CPMG T2 of the lung was strongly dependent upon the IPDT, in contrast to muscle and brain tissues. The IPDT dependence of the CPMG T2 for lung tissue, which was lessened by degassing, was affected by the magnetic field inhomogeneity due to air-tissue interfaces, but not by the spin-locking effect, since the T2 measured by the Carr-Purcell-Freeman-Hill (CPFH) method did not show this dependence. These results should aid in the evaluation of T2 values for biological tissues measured under various conditions and by different techniques.

摘要

为了在核磁共振测量中确定生物组织的横向弛豫时间（T2），人们推荐采用 Carr-Purcell-Meiboom-Gill（CPMG）方法，以避免外部磁场不均匀性对 T2 值的影响。然而，对于生物组织，已表明在 CPMG 测量中 T2 与脉冲间隔时间（IPDT）有关。本研究考察了肌肉、肺（被动塌陷或除气）和脑组织中 T2 对 IPDT 的依赖性。结果发现，与肌肉和脑组织不同，肺的 CPMG T2 强烈依赖于 IPDT。肺组织的 CPMG T2 对 IPDT 的依赖性在除气后有所减弱，它受气-组织界面导致的磁场不均匀性影响，但不受自旋锁定效应影响，因为用 Carr-Purcell-Freeman-Hill（CPFH）方法测量的 T2 并未显示出这种依赖性。这些结果应有助于评估在各种条件下通过不同技术测量的生物组织的 T2 值。