Chen X J, Chawla M S, Hedlund L W, Möller H E, MacFall J R, Johnson G A
Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina 27710, USA.
Magn Reson Med. 1998 Jan;39(1):79-84. doi: 10.1002/mrm.1910390113.
A technique using hyperpolarized (HP) 3He to image the small airways of the lung by using moderate flip angles and a short scanning period during early inspiration is demonstrated. Flip angles (alpha) ranging from 10-90 degrees were used in guinea pig experiments with scanning during the entire inspiration period. A second series acquired data throughout a short window of the ventilatory cycle with alpha = 45 degrees. The success of the animal studies has motivated implementation of similar imaging techniques in the clinical arena. Human studies involved imaging over the total inspiration period with alpha approximately 10 degrees. The first series of guinea pig experiments demonstrated that larger flip angles (50-90 degrees) destroy the magnetization before it reaches the smaller airways. At moderate flip angles (20-40 degrees), airway branching down to the fourth generation was apparent. Fifth-order branchings were seen in the images of the second series. The trachea down to fourth generation pulmonary airway branching, along with some distal air spaces, was seen in the human lung images.
展示了一种利用超极化（HP）³He 通过在早期吸气期间使用适度翻转角和短扫描周期对肺小气道进行成像的技术。在豚鼠实验中，在整个吸气期进行扫描时使用了 10 - 90 度范围的翻转角（α）。第二个系列在通气周期的短窗口内以α = 45 度获取数据。动物研究的成功促使在临床领域实施类似的成像技术。人体研究涉及在整个吸气期以约 10 度的α进行成像。豚鼠实验的第一个系列表明，较大的翻转角（50 - 90 度）会在磁化到达较小气道之前将其破坏。在适度翻转角（20 - 40 度）下，向下延伸至第四代的气道分支清晰可见。在第二个系列的图像中看到了五级分支。在人体肺部图像中可见气管直至第四代肺气道分支以及一些远端气腔。
