LUNG PARENCHYMA - MAGNETIC-SUSCEPTIBILITY IN MR IMAGING
LUNG PARENCHYMA - MAGNETIC-SUSCEPTIBILITY IN MR IMAGING
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DOI：
10.1148/radiology.180.3.1871305
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发表时间：
1991-09-01
期刊：
影响因子：
19.7
通讯作者：
PAULY, JM
中科院分区：
文献类型：
--
作者：
BERGIN, CJ;GLOVER, GH;PAULY, JM
正常肺实质的磁共振（MR）成像中的磁化率效应是由于肺的微观不均匀性引起的磁场不均匀性而发生的。 对肺的MR成像的影响是来自体素内相位分散（用T2 '测量）的信号损失和宏观共振频率从水的共振频率向空气的共振频率的偏移（Δ-上升）。 通过测量两名成年志愿者和一个切除的充气人肺中不同位置的T2 '衰减和Δ-上升来定量1.5T下MR成像的这些影响。 在切除的膨胀标本中，平均T2 '为7毫秒，在正常的体内肺中为6.3毫秒。 从非依赖性肺到依赖性肺，T2 '有重力增加。 肺不张肺组织中T2 '增加到35毫秒，肿瘤中超过140毫秒。 肺的宏观共振频率比纵隔肌的共振频率高3.6ppm。 这些值对于开发适合于成像肺实质的MR脉冲序列是重要的。
Magnetic susceptibility effects in magnetic resonance (MR) imaging of normal lung parenchyma occur because of magnetic-field inhomogeneities induced by the microscopic heterogeneity of the lung. The effects on MR imaging of the lung are loss of signal from intravoxel phase dispersion (measured with T2') and a shift in the macroscopic resonant frequency from that of water toward that of air (DELTA-upsilon). These effects of MR imaging at 1.5 T were quantitated by measuring T2' decay and DELTA-upsilon at different locations in the lungs of two adult volunteers and one excised inflated human lung. The average T2' was 7 msec in the excised inflated specimen and 6.3 msec in normal in vivo lungs. There was a gravitational increase in T2' from nondependent to dependent lung. T2' increased to 35 msec in atelectatic lung tissue and to more than 140 msec in tumor. The macroscopic resonant lung frequency increased to 3.6 ppm more than that of mediastinal muscle. These values are important for developing MR pulse sequences appropriate for imaging lung parenchyma.