Jordan Bénédicte F, Cron Greg O, Gallez Bernard
Laboratory of Biomedical Magnetic Resonance, Université Catholique de Louvain, Brussels, Belgium.
Magn Reson Med. 2009 Mar;61(3):634-8. doi: 10.1002/mrm.21594.
The aim of this study was to develop an MRI fluorocarbon oximetry technique using snapshot inversion recovery and compare it with fluorescence quenching fiber-optic probe oximetry (OxyLite) performed simultaneously in experimental mouse tumors. The oxygen reporter probe hexafluorobenzene (HFB) was injected directly into the tumors, along with the insertion of the OxyLite probe. Tumor oxygenation (pO(2)) was modified using carbogen or lethal doses of the anesthetic gas. MRI pO(2) maps were generated in 1.5 min with an in-plane spatial resolution of 1.88 mm. MRI and OxyLite showed consistent baseline and postmortem pO(2) values. Increases in tumor pO(2) during carbogen breathing showed similar kinetics for the two methods. The pO(2) values observed using the OxyLite corresponded with relatively hypoxic values observed by MRI. The apparent discrepancy between mean values might be due to the difference in sampling volumes of the techniques and the observation of multiple locations using (19)F MRI versus a single location using the large optical fiber. Overall, the present method provides a rapid way to map the tumor oxygenation and is particularly suitable to monitor acute changes of pO(2) in tumors.
本研究的目的是开发一种利用快照反转恢复的MRI氟碳血氧测定技术，并将其与在实验小鼠肿瘤中同时进行的荧光猝灭光纤探针血氧测定法（OxyLite）进行比较。将氧报告探针六氟苯（HFB）与OxyLite探针一同直接注射到肿瘤中。使用混合气或致死剂量的麻醉气体改变肿瘤氧合（pO₂）。在1.5分钟内生成平面空间分辨率为1.88毫米的MRI pO₂图。MRI和OxyLite显示出一致的基线和死后pO₂值。在混合气呼吸期间肿瘤pO₂的增加在两种方法中显示出相似的动力学。使用OxyLite观察到的pO₂值与MRI观察到的相对低氧值相对应。平均值之间的明显差异可能是由于技术的采样体积不同以及使用¹⁹F MRI观察多个位置与使用大型光纤观察单个位置所致。总体而言，本方法提供了一种快速绘制肿瘤氧合图的方法，特别适合于监测肿瘤中pO₂的急性变化。
