超极化气体肺部磁共振成像

磁共振成像(MRI)技术具有非侵入、无放射性的特点,在临床疾病诊断中具有独特的优势,但是肺部空腔的特殊结构使传统质子MRI无法对其直接成像.自旋交换光抽运(SEOP)方法可以使惰性气体原子的极化度增强4个量级以上,从而使肺部的气体MRI成为可能.该文介绍了超极化惰性气体肺部MRI的最新研究进展,包括超极化气体磁共振相关参数的测量方法、肺部通气结构成像、肺部气体交换功能成像,同时比较了常用于肺部MRI气体的优点和缺点.

Lung MRI Using Hyperpolarized Gases

Magnetic resonance imaging (MRI) is a nonradioactive and noninvasive medical imaging technique, and it has been widely applied in the clinical diagnosis. However, using conventional proton MRI to obtain lung images is difficult, because the proton density in the lungs is about three orders of magnitude lower than that in other organs/tissues due to air cavities in the lungs. Hyperpolarized noble gases can be used as contrast agents for lung MRI. Spin-exchange optical pumping (SEOP) is a technique that can be used to enhance the nuclear spin polarizations of noble gases more than 10 000 folds, which makes noble gas lung MRI feasible. In this paper, the recent developments of hyperpolarized gases lung MRI were reviewed. Topics covered include comparison of different hyperpolarized noble gases used for lung MRI, unconventional methods for measuring quantitative parameters in hyperpolarized gas MRI, and the most updated applications of hyperpolarized gas MRI in assessing pulmonary structure and function.