Organ-specific effects of oxygen and carbogen gas inhalation on tissue longitudinal relaxation times
Organ-specific effects of oxygen and carbogen gas inhalation on tissue longitudinal relaxation times
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DOI：
10.1002/mrm.21357
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发表时间：
2007-09-01
影响因子：
3.3
通讯作者：
Parker, Geoff J. M.
中科院分区：
文献类型：
--
作者：
O'Connor, James P. B.;Jackson, Alan;Parker, Geoff J. M.
分子氧以前已被证明可以缩短脾和肾皮质的纵向弛豫时间（T-1），但不能缩短肝脏或脂肪的纵向弛豫时间。在这项研究中，这种影响的大小和时间演变进行了调查。在16名健康志愿者中依次给予医用空气、氧气和碳源（95%氧气/5%CO2）。使用扰相梯度回波序列（TR = 3.5 ms，TE = 0.9 ms，α = 2度/8度/17度）采集T，标测图，空气采集6次，氧气采集12次，二氧化碳采集12次，空气采集6 - 12次。通过单因素方差分析比较了肝脏、脾脏、骨骼肌、肾皮质和脂肪中气体吸入各阶段之间的平均T值和舒张率变化。氧诱导的T-1缩短发生在禁食受试者的肝脏中（P < 0.001），但在非禁食受试者中没有发生（P = 0.244）。脾和肾皮质的T-1缩短（均P < 0.001）大于先前报道的。碳源在不同器官中引起相互冲突的反应，表明与器官血管系统的复杂关系。氧使组织T缩短比以前认识到的更明显和更复杂。这种效应可能是有用的动脉血流和氧输送到血管床的生物标志物。
Molecular oxygen has been previously shown to shorten longitudinal relaxation time (T-1) in the spleen and renal cortex, but not in the liver or fat. In this study, the magnitude and temporal evolution of this effect were investigated. Medical air, oxygen, and carbogen (95% oxygen/5% CO2) were administered sequentially in 16 healthy volunteers. T, maps were acquired using spoiled gradient echo sequences (TR = 3.5 ms, TE = 0.9 ms, alpha = 2 degrees/8 degrees/17 degrees) with six acquisitions on air, 12 on oxygen, 12 on carbogen, and six to 12 back on air. Mean T, values and change in relaxation rate were compared between each phase of gas inhalation in the liver, spleen, skeletal muscle, renal cortex, and fat by one-way analysis of variance. Oxygen-induced T-1-shortening occurred in the liver in fasted subjects (P < 0.001) but not in non-fasted subjects (P = 0.244). T-1-shortening in spleen and renal cortex (both P < 0.001) were greater than previously reported. Carbogen induced conflicting responses in different organs, suggesting a complex relationship with organ vasculature. Shortening of tissue T, by oxygen is more pronounced and more complex than previously recognized. The effect may be useful as a biomarker of arterial flow and oxygen delivery to vascular beds.