Hyperpolarized 3He and 129Xe MR Imaging in Healthy Volunteers and Patients with Chronic Obstructive Pulmonary Disease
Hyperpolarized 3He and 129Xe MR Imaging in Healthy Volunteers and Patients with Chronic Obstructive Pulmonary Disease
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DOI：
10.1148/radiol.12120485
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发表时间：
2012-11-01
期刊：
影响因子：
19.7
通讯作者：
Parraga, Grace
中科院分区：
文献类型：
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作者：
Kirby, Miranda;Svenningsen, Sarah;Parraga, Grace
目的：定量比较健康志愿者和慢性阻塞性肺疾病（COPD）患者5分钟内获得的超极化氦3 （He-3）和氙129 （Xe-129）磁共振（MR）图像，并评估He-3和Xe-129磁共振成像测量值与肺活量测定和体积脉搏图测量值之间的相关性。材料和方法：本研究经伦理委员会批准并符合HIPAA。所有受试者均获得书面知情同意。8名健康志愿者和10名慢性阻塞性肺病患者接受了磁共振成像、肺活量测定和体积描记术。采用半自动分割法获得He-3和Xe-129成像的通气缺陷百分比（vdp）。根据He-3 （b = 1.6 sec/cm(2)）和Xe-129 （b = 12 sec/cm(2)）扩散加权图像计算表观扩散系数（adc）。超极化He-3和Xe-129成像的vdp比较采用双尾Wilcoxon符号秩检验和方差分析；Pearson相关系数用于评价测量值之间的关系。结果：COPD患者的he -129 VDP显著高于He-3 VDP (P < 0.0001)，而健康志愿者的he -129 VDP不显著（P = 0.35），尽管3He和Xe-129 VDP在所有受试者中均显示出显著相关性（r = 0.91, P < 0.0001）。1秒用力呼气量（FEV1）与He-3 VDP （r = 20.84, P < 0.0001）、Xe-129 VDP （r = -0.89, P < 0.0001）的相关性相似且极显著，但FEV1/用力肺活量（FVC）比值与he -129 VDP （r = -0.95, P < 0.0001）的相关性显著高于FEV1/FVC与He-3 VDP （r = 20.84, P < 0.0001）。He-3与Xe-129 ADC也存在显著相关性（r = 0.97, P < 0.0001）；x -129 ADC与肺一氧化碳弥散能力（r = 20.79, P = 0.03）和计算机体层摄影肺气肿测量值（衰减值在第15百分位的区域：r = 20.91, P = 0.0003；衰减值小于2950 HU的相对区域：r = 0.87, P = 0.001）显著相关。结论：在COPD患者中，超极化Xe-29 MR成像获得的VDP明显大于He-3 MR成像，提示肺区域充盈不完全或延迟，这可能与Xe-129气体的不同性质以及COPD的生理和/或解剖异常有关。
Purpose: To quantitatively compare hyperpolarized helium 3 (He-3) and xenon 129 (Xe-129) magnetic resonance (MR) images obtained within 5 minutes in healthy volunteers and patients with chronic obstructive pulmonary disease (COPD) and to evaluate the correlations between He-3 and Xe-129 MR imaging measurements and those from spirometry and plethysmography.Materials and Methods: This study was approved by an ethics board and compliant with HIPAA. Written informed consent was obtained from all subjects. Eight healthy volunteers and 10 patients with COPD underwent MR imaging, spirometry, and plethysmography. Ventilation defect percentages (VDPs) at He-3 and Xe-129 imaging were obtained by using semiautomated segmentation. Apparent diffusion coefficients (ADCs) were calculated from He-3 (b = 1.6 sec/cm(2)) and Xe-129 (b = 12 sec/cm(2)) diffusion-weighted images. VDPs at hyperpolarized He-3 and Xe-129 imaging were compared with a two-tailed Wilcoxon signed rank test and analysis of variance; Pearson correlation coefficients were used to evaluate the relationships among measurements.Results: Xe-129 VDP was significantly greater than He-3 VDP for patients with COPD (P < .0001) but not for healthy volunteers (P = .35), although 3He and Xe-129 VDPs showed a significant correlation for all subjects (r = 0.91, P < .0001). The forced expiratory volume in 1 second (FEV1) showed a similar and significant correlation with He-3 VDP (r = 20.84, P < .0001) and Xe-129 VDP (r = -0.89, P < .0001), although the correlation between the FEV1/forced vital capacity (FVC) ratio and Xe-129 VDP (r = -0.95, P < .0001) was significantly greater (P = .01) than that for FEV1/FVC and He-3 VDP (r = 20.84, P < .0001). A significant correlation was also observed for He-3 and Xe-129 ADC (r = 0.97, P < .0001); Xe-129 ADC was significantly correlated with diffusing capacity of lung for carbon monoxide (r = 20.79, P = .03) and computed tomographic emphysema measurements (areas with attenuation values in the 15th percentile: r = 20.91, P = .0003; relative areas with attenuation values of less than 2950 HU: r = 0.87, P = .001).Conclusion: In patients with COPD, the VDP obtained with hyperpolarized Xe-29 MR imaging was significantly greater than that with He-3 MR imaging, suggesting incomplete or delayed filling of lung regions that may be related to the different properties of Xe-129 gas and physiologic and/or anatomic abnormalities in COPD.