在 7T 下对荷瘤小鼠进行氧消耗研究的定量 17O 成像。

Quantitative 17O imaging towards oxygen consumption study in tumor bearing mice at 7 T.

机构信息

Molecular Imaging Research Center, National Institute of Radiological Sciences, Chiba, Japan.

出版信息

Magn Reson Imaging. 2013 Jun;31(5):643-50. doi: 10.1016/j.mri.2012.10.009. Epub 2013 Jan 5.

DOI:10.1016/j.mri.2012.10.009

Abstract

(17)O magnetic resonance imaging (MRI) using a conventional pulse sequence was explored as a method of quantitative imaging towards regional oxygen consumption rate measurement for tumor evaluation in mice. At 7 T, fast imaging with steady state (FISP) was the best among gradient echo, fast spin echo and FISP for the purpose. The distribution of natural abundance H2(17)O in mice was visualized under spatial resolution of 2.5 × 2.5mm(2) by FISP in 10 min. The signal intensity by FISP showed a linear relationship with (17)O quantity both in phantom and mice. Following the injection of 5% (17)O enriched saline, (17)O re-distribution was monitored in temporal resolution down to 5 sec with an image quality sufficient to distinguish each organ. The image of labeled water produced from inhaled (17)O2 gas was also obtained. The present method provides quantitative (17)O images under sufficient temporal and spatial resolution for the evaluation of oxygen consumption rate in each organ. Experiments using various model compounds of R-OH type clarified that the signal contribution of body constituents other than water in the present in vivo(17)O FISP image was negligible.

摘要

（17）采用常规脉冲序列的磁共振成像（MRI）被探索作为一种定量成像方法，用于测量小鼠肿瘤的区域耗氧量以进行评估。在 7T 下，梯度回波、快速自旋回波和 FISP 中，快速稳态成像（FISP）最适合该目的。通过 FISP 在 10 分钟内在 2.5×2.5mm（2）的空间分辨率下可视化小鼠中天然丰度 H2（17）O 的分布。FISP 的信号强度与体模和小鼠中的（17）O 量呈线性关系。在注射 5%（17）O 浓缩盐水后，（17）O 的再分布可以以足够区分每个器官的图像质量达到 5 秒的时间分辨率进行监测。吸入（17）O2 气体产生的标记水的图像也被获得。本方法提供了在足够的时间和空间分辨率下的定量（17）O 图像，用于评估每个器官的耗氧量。使用各种 R-OH 型模型化合物的实验表明，在本体内（17）O FISP 图像中，除水以外的身体成分的信号贡献可以忽略不计。