Meyer M E, Yu O, Eclancher B, Grucker D, Chambron J
Institut de Physique Biologique, Faculté de Médecine, Strasbourg, France.
Magn Reson Med. 1995 Aug;34(2):234-41. doi: 10.1002/mrm.1910340215.
A linear relationship between the proton relaxation rates and the fraction of deoxyhemoglobin of circulating whole blood (fHb) has been established in vitro at 4.7 T. These results have been interpreted on the basis of the additivity of relaxation rates. The slope of the lines of transverse relaxation rates (R2) versus fHb was found to increase with interpulse delay in Carr-Purcell Meiboom-Gill (CPMG) experiments. The Luz-Meiboom relation applied to this interpulse delay dependence of R2 suggests a two-site chemical exchange rather than a diffusion mechanism. The 1-ms water proton exchange time derived from these observations has been interpreted in terms of exchange between exchangeable protons close to the paramagnetic center of hemoglobin and protons of bulk water.
在4.7T的体外条件下，已建立了质子弛豫率与循环全血中脱氧血红蛋白分数（fHb）之间的线性关系。这些结果已根据弛豫率的加和性进行了解释。在Carr-Purcell Meiboom-Gill（CPMG）实验中，发现横向弛豫率（R2）与fHb的关系曲线斜率随脉冲间隔延迟而增加。将Luz-Meiboom关系应用于R2对该脉冲间隔延迟的依赖性表明存在双位点化学交换而非扩散机制。从这些观察结果得出的1毫秒水质子交换时间已根据接近血红蛋白顺磁中心的可交换质子与大量水质子之间的交换进行了解释。
