Chen X J, Chawla M S, Cofer G P, Hedlund L W, Möller H E, Johnson G A
Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina 27710, USA.
Magn Reson Med. 1998 Jul;40(1):61-5. doi: 10.1002/mrm.1910400109.
Spatially localized lineshapes of hyperpolarized (HP) 3He in guinea pig lungs have been measured in vivo. Three different axial slice locations, each containing different compositions of airway sizes and orientations, were studied. Gas peaks from major bronchi (2 ppm) and alveoli (-2 ppm) were distinguished. The gas phase spectra show structural features that are a result of frequency shifts caused by bulk magnetic susceptibility. For a given slice, the spectral lineshapes reflect the airway composition within the slice location, according to theory. The peak assignments given here also agree with previous studies done by Wagshul et al. with HP 129Xe. At each of the slice locations, data were acquired during two phases of the breathing cycle, resulting in a relative frequency shift of approximately 0.3 ppm in the superior slices. Spectra obtained over a number of breaths show the dynamics of the gas buildup in the lung and provide further evidence supporting the peak assignments.
已在体内测量了豚鼠肺中超极化（HP）3He的空间局部线形。研究了三个不同的轴向切片位置，每个位置包含不同气道大小和方向的组成。区分了来自主支气管（2 ppm）和肺泡（-2 ppm）的气体峰。气相光谱显示出由于体磁化率引起的频移导致的结构特征。根据理论，对于给定的切片，光谱线形反映了切片位置内的气道组成。这里给出的峰归属也与Wagshul等人用HP 129Xe进行的先前研究一致。在每个切片位置，在呼吸周期的两个阶段采集数据，导致上叶切片中相对频移约0.3 ppm。在多次呼吸中获得的光谱显示了肺中气体积聚的动态，并提供了支持峰归属的进一步证据。
