From the Université Bordeaux, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, CIC 1401, Bordeaux, France (I.B., P.B., P.O.G., F.L., G.D.); Centre de Recherche Cardio-Thoracique de Bordeaux, INSERM U1045, Université Bordeaux Segalen, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France (I.B., P.B., P.O.G., F.L., G.D.); and CHU de Bordeaux, Service d'Imagerie Thoracique et Cardiovasculaire, Service des Maladies Respiratoires, Service d'Exploration Fonctionnelle Respiratoire, CIC 1401, France (I.B., P.B., P.O.G., C.D., J.M., F.L., G.D.).
Radiology. 2019 Jul;292(1):216-225. doi: 10.1148/radiol.2019190052. Epub 2019 Jun 4.
Background The validity of three-dimensional (3D) ultrashort echo time (UTE) MRI for the assessment of emphysema in patients with chronic obstructive pulmonary disease (COPD) at high spatial resolution is, to the knowledge of the authors, unknown. Purpose To assess whether noncontrast agent-enhanced 3D UTE MRI at submillimeter spatial resolution can be used to determine the extent of emphysema by using both qualitative visual scoring and fully automated volumetric quantification. Materials and Methods Twenty-eight participants with COPD and 10 control participants (mean age, 70 years ± 7 [standard deviation] and 64 years ± 4, respectively) were prospectively enrolled between 2015 and 2017. Participants underwent pulmonary function testing, CT, and MRI. CT was used as the reference standard. Qualitative scoring of emphysema extent was performed by two readers. Fully automated quantification of percentage of low-attenuation volume by using a threshold of -950 HU (%LAV) at CT and percentage of low-signal-intensity volume by using an adaptive threshold of 0.20 (%LSV) at MRI were the respective emphysema indexes. Comparison of means was performed by using Student test, correlation was determined by using Pearson test, agreement was found by using weighted κ index, and reproducibility was determined by using intraclass correlation coefficient. Diagnostic performance was assessed by calculating the area under the receiver operating characteristics curve (AUC). Results With qualitative scoring, agreement between UTE MRI and CT was good (weighted κ, 0.79; 95% confidence interval: 0.71, 0.83). With automated volumetric quantification, %LSV was significantly correlated with %LAV in participants with COPD (, -0.80; < .001) and correlated with forced expiratory volume in 1 second percentage predicted (, -0.55; = .002). %LSV was significantly higher in participants with COPD than in control participants ( < .001). The diagnostic performance and reproducibility of %LSV were good (AUC, 1.00 [95% confidence interval: 0.88, 1.00], and intraclass correlation coefficient, > 0.99, respectively). Conclusion A fully automated method with three-dimensional ultrashort echo time MRI reproducibly quantified the volumetric extent of emphysema in participants with chronic obstructive pulmonary disease. © RSNA, 2019
在高空间分辨率下，三维（3D）超短回波时间（UTE）MRI 评估慢性阻塞性肺疾病（COPD）患者肺气肿的有效性，据作者所知，尚不清楚。目的：评估亚毫米空间分辨率的非增强 3D UTE MRI 是否可用于通过定性视觉评分和全自动容积定量来确定肺气肿的程度。材料与方法：2015 年至 2017 年期间，前瞻性纳入 28 名 COPD 患者和 10 名对照参与者（平均年龄，分别为 70 岁±7[标准差]和 64 岁±4）。参与者接受了肺功能测试、CT 和 MRI。CT 用作参考标准。两位读者对肺气肿程度进行了定性评分。通过使用 -950 HU（%LAV）的阈值在 CT 上对低衰减体积的百分比进行全自动定量，以及在 MRI 上使用 0.20 的自适应阈值对低信号强度体积的百分比（%LSV）进行全自动定量，分别作为肺气肿指标。使用学生 t 检验比较均值，使用 Pearson 检验确定相关性，使用加权 κ 指数确定一致性，使用组内相关系数确定可重复性。通过计算接收者操作特征曲线（AUC）下的面积来评估诊断性能。结果：定性评分时，UTE MRI 与 CT 的一致性良好（加权 κ，0.79；95%置信区间：0.71，0.83）。在 COPD 患者中，使用自动容积定量法，%LSV 与 %LAV 显著相关（，-0.80；<.001），与用力呼气量占预计值的百分比相关（，-0.55；=.002）。%LSV 在 COPD 患者中明显高于对照组（<.001）。%LSV 的诊断性能和可重复性良好（AUC，1.00[95%置信区间：0.88，1.00]，组内相关系数>0.99）。结论：一种使用三维超短回波时间 MRI 的全自动方法可重复性地定量 COPD 患者肺气肿的容积程度。
