APPLICATION OF CONTINUOUS RELAXATION-TIME DISTRIBUTIONS TO THE FITTING OF DATA FROM MODEL SYSTEMS AND EXCISED TISSUE
APPLICATION OF CONTINUOUS RELAXATION-TIME DISTRIBUTIONS TO THE FITTING OF DATA FROM MODEL SYSTEMS AND EXCISED TISSUE
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DOI：
10.1002/mrm.1910200205
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发表时间：
1991-08-01
影响因子：
3.3
通讯作者：
ALLEN, PS
中科院分区：
文献类型：
--
作者：
MENON, RS;ALLEN, PS
生物系统在许多不同的水平上表现出异质性，这导致了对组织样品中水质子的多个弛豫时间分量的期望。将松弛数据与离散分量的先验数量相匹配的传统方法在解释这些数据时容易受到观察者偏差的影响，而且，与产生连续松弛时间分布的方法相比，对于非均质系统来说，直观地讲，这种方法不太现实。以前对连续分布技术的验证是在假设均匀高斯噪声的模拟数据上进行的。在目前的工作中，我们研究了一种特殊的线性逆理论技术从可控模型系统上的数据中再现已知松弛时间分布的能力。此外，利用在模型系统上获得的经验，我们将同样的技术应用于对切除脑组织的体外松弛时间测量中的分析，发现对于白质中的水质子，横向松弛有四个可重复的成分，而灰质只有两个。纵向松弛只显示白质或灰质中的一种成分。©1991学术出版社，Inc.
Biological systems exhibit heterogeneity at many different levels, leading to the expectation of multiple relaxation time components for water protons in tissue samples. Traditional methods which fit the relaxation data to an a priori number of discrete components are open to observer bias in their interpretation of this data, and moreover, are intutively less realistic for heterogeneous systems than methods which produce continuous relaxation time distributions. Previous validations of continuous distribution techniques have been made on simulated data assuming uniform Gaussian noise. In the current work we have investigated the ability of one particular linear inverse theory technique to reproduce known relaxation time distributions from the data on a controllable model system. Furthermore, using the experience gained on the model system, we have applied this same technique to the analysis ofin vitrorelaxation time measurements on excised brain tissue and found for water protons in white matter, four reproducible components for the transverse relaxation, whereas gray matter gave rise to only two. The lougitudinal relaxation displayed only one component in either white matter or gray matter. © 1991 Academic Press, Inc.