T2*and proton density measurement of normal human lung parenchyma using submillisecond echo time gradient echo magnetic resonance imaging
T2*and proton density measurement of normal human lung parenchyma using submillisecond echo time gradient echo magnetic resonance imaging
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DOI：
10.1016/s0720-048x(98)00169-7
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发表时间：
1999-03-01
影响因子：
3.3
通讯作者：
Gefter, WB
中科院分区：
文献类型：
--
作者：
Hatabu, H;Alsop, DC;Gefter, WB
目的：利用亚毫秒回波时间（TE）梯度回波（GRE）磁共振（MR）成像技术获得正常人体内肺实质的T2*和质子密度测量值。材料和方法：采用1.5 t系统，配备原型增强梯度（GE Signa, Waukausha， WI）扫描6名正常志愿者。屏气时获取图像，采集时间为7 ~ 16 s。测试了0.7 ~ 2.5 ms范围内的多个te。对信号强度与TE、屈服、T2*测量和相对于胸壁肌肉的质子密度的对数图进行线性回归。比较了仰卧位和俯卧位的测量结果，并评估了肺膨胀水平对肺信号的影响。结果：肺实质信号随TE的延长呈指数衰减。6名正常志愿者T2*的测量范围为0.89 ~ 2.18 ms（±0.41 ms，平均±标准差）。测量到的相对质子密度值在0.21 ~ 0.45之间（0.29 +/- 0.08，平均+/- sd）。计算出仰卧位右肺前、中、后段T2*值分别为1.46 +/- 0.50、1.01 +/- 0.29、1.52 +/- 0.18 ms，计算出相对质子密度分别为0.20 +/- 0.03、0.32 +/- 0.13、0.35 +/- 0.10。俯卧位前后质子密度梯度反转。最大呼气时肺实质信号较最大吸气时明显增加。超短TE GRE技术产生的图像显示了肺实质的信号，运动引起的噪声最小。结论：使用一组非常快速的屏气图像，结合最近开发的超短TE GRE序列，可以获得肺T2*和相对质子密度的定量体内测量，并结合高信号实质图像。1999爱思唯尔科学爱尔兰有限公司版权所有。
Objective: To obtain T2* and proton density measurements of normal human lung parenchyma in vivo using submillisecond echo time (TE) gradient echo (GRE) magnetic resonance (MR) imaging, Materials and methods: Six normal volunteers were scanned using a 1.5-T system equipped with a prototype enhanced gradient (GE Signa, Waukausha, WI). Images were obtained during breath-holding with acquisition times of 7-16 s. Multiple TEs ranging from 0.7 to 2.5 ms were tested. Linear regression was performed on the logarithmic plots of signal intensity versus TE, yielding, measurements of T2* and proton density relative to chest wall muscle. Measurements in supine and prone positions were compared, and effects of the level of lung inflation on lung signal were also evaluated. Results: The signal from the lung parenchyma diminished exponentially with prolongation of TE. The measured T2* in six normal volunteers ranged from 0.89 to 2.18 ms (1.43 +/- 0.41 ms, mean +/- S.D.). The measured relative proton density values ranged between 0.21 and 0.45 (0.29 +/- 0.08, mean +/- S.D.). Calculated T2* values of 1.46 +/- 0.50, 1.01 +/- 0.29 and 1.52 +/- 0.18 ms, and calculated relative proton densities of 0.20 +/- 0.03, 0.32 +/- 0.13 and 0.35 +/- 0.10 were obtained from the anterior, middle and posterior portions of the supine right lung, respectively. The anterior-posterior proton density gradient was reversed in the prone position. There was a pronounced increase in signal from lung parenchyma at maximum expiration compared with maximum inspiration. The ultrashort TE GRE technique yielded images demonstrating signal from lung parenchyma with minimal motion-induced noise. Conclusion: Quantitative in vivo measurements of lung T2* and relative proton density in conjunction with high-signal parenchymal images can be obtained using a set of very rapid breath-hold images with a recently developed ultrashort TE GRE sequence. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.