Solyanik Olga, Hollmann Patrick, Dettmer Sabine, Kaireit Till, Schaefer-Prokop Cornelia, Wacker Frank, Vogel-Claussen Jens, Shin Hoen-oh
Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hanover, Germany; Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research, Hanover, Germany.
Institute of Diagnostic and Interventional Radiology, Kantonsspital, Aarau, Switzerland.
PLoS One. 2015 Oct 2;10(10):e0139102. doi: 10.1371/journal.pone.0139102. eCollection 2015.
To determine whether density mapping (DM) is more accurate for detection and quantification of pathologic air trapping (pAT) in patients after lung transplantation compared to other CT air trapping measures. One-hundred forty-seven lung and heart-lung transplant recipients underwent CT-examinations at functional residual capacity (FRC) and total lung capacity (TLC) and PFT six months after lung transplantation. Quantification of air trapping was performed with the threshold-based method in expiration (EXP), density mapping (DM) and the expiratory to inspiratory ratio of the mean lung density (E/I-ratio MLD). A non-rigid registration of inspiration-expiration CT-data with a following voxel-to-voxel mapping was carried out for DM. Systematic variation of attenuation ranges was performed for EXP and DM and correlated with the ratio of residual volume to total lung capacity (RV/TLC) by Spearman rank correlation test. AT was considered pathologic if RV/TLC was above the 95th percentile of the predicted upper limit of normal values. Receiver operating characteristic (ROC) analysis was performed. The optimal attenuation range for the EXP method was from -790 HU to -950 HU (EXP(-790 to -950HU)) (r = 0.524, p<0.001) to detect air trapping. Within the segmented lung parenchyma, AT was best defined as voxel difference less than 80 HU between expiration and registered inspiration using the DM method. DM correlated best with RV/TLC (r = 0.663, p<0.001). DM and E/I-ratio MLD showed a larger AUC (0.78; 95% CI 0.69-0.86; 0.76, 95% CI 0.67-0.85) than EXP(-790 HU to -950 HU) (0.71, 95% CI 0.63-0.78). DM and E/I-ratio MLD showed better correlation with RV/TLC and are more suited quantitative CT-methods to detect pAT in lung transplant patients than the EXP(-790HU to -950HU).
为了确定与其他CT肺气体陷闭测量方法相比，密度映射（DM）在检测和量化肺移植患者的病理性气体陷闭（pAT）方面是否更准确。147例肺移植和心肺移植受者在肺移植后6个月进行了功能残气量（FRC）、肺总量（TLC）时的CT检查及肺功能测试（PFT）。采用基于阈值的呼气法（EXP）、密度映射（DM）以及平均肺密度的呼气与吸气比值（E/I-ratio MLD）对气体陷闭进行量化。对DM进行吸气-呼气CT数据的非刚性配准及随后的体素到体素映射。对EXP和DM进行衰减范围的系统变化，并通过Spearman等级相关检验将其与残气量与肺总量比值（RV/TLC）相关联。如果RV/TLC高于预测正常值上限的第95百分位数，则将气体陷闭视为病理性。进行了受试者操作特征（ROC）分析。EXP方法检测气体陷闭的最佳衰减范围为-790 HU至-950 HU（EXP(-790至-950HU)）（r = 0.524，p<0.001）。在分割的肺实质内，使用DM方法将气体陷闭最佳定义为呼气与配准吸气之间体素差异小于80 HU。DM与RV/TLC的相关性最佳（r = 0.663，p<0.001）。与EXP(-790 HU至-950 HU)（0.71，95% CI 0.63-0.78）相比，DM和E/I-ratio MLD显示出更大的曲线下面积（AUC）（0.78；95% CI 0.69-0.86；0.76，95% CI 0.67-0.85）。DM和E/I-ratio MLD与RV/TLC的相关性更好，并且与EXP(-790HU至-950HU)相比，是更适合检测肺移植患者pAT的定量CT方法。
