Kaireit Till F, Kern Agilo, Voskrebenzev Andreas, Pöhler Gesa H, Klimes Filip, Behrendt Lea, Gutberlet Marcel, Moher-Alsady Tawfik, Dittrich Anna-Maria, Wacker Frank, Hohlfeld Jens, Vogel-Claussen Jens
Department for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.
Biomedical Research in Endstage and Obstructive Lung Disease (BREATH), Member of the German Lung Research Center (DZL), Hannover, Germany.
J Magn Reson Imaging. 2021 Apr;53(4):1092-1105. doi: 10.1002/jmri.27452. Epub 2020 Nov 27.
Regional flow volume loop ventilation-weighted noncontrast-enhanced proton lung MRI in free breathing has emerged as a novel technique for assessment of regional lung ventilation, but has yet not been validated with Xenon MRI ( Xe-MRI), a direct visualization of ventilation in healthy volunteers, cystic fibrosis (CF), and chronic obstructive pulmonary disease (COPD) patients.
To compare regional ventilation and regional flow volume loops measured by noncontrast-enhanced ventilation-weighted phase-resolved functional lung MRI (PREFUL-MRI) with Xe-MRI ventilation imaging and with lung function test parameters.
Retrospective study.
Twenty patients with COPD, eight patients with CF, and six healthy volunteers.
FIELD STRENGTH/SEQUENCE: PREFUL and Xe-MRI gradient echo sequences were acquired at 1.5T.
Coronal slices of PREFUL-MRI (free breathing) and Xe-MRI (single breath-hold) were acquired on the same day, matched by their ventrodorsal position and coregistered for evaluation. Ventilation defect percentage (VDP) was calculated based on regional ventilation (RV), regional flow volume loops (RFVL), or Xe-MRI with two different threshold methods. A combined VDP was calculated for RV and RFVL. Additionally, lung function testing was performed (such as the forced expiratory volume in 1 second [FEV ]) was used.
The obtained parameters were compared using Wilcoxon tests, correlated using Spearman's correlation coefficient (r), and agreement between PREFUL and Xe-MRI parameters was assessed using Bland-Altman analysis and Dice coefficients.
VDP measured by PREFUL and Xe were significantly correlated with both thresholding techniques (r = 0.62-0.69, P < 0.05 for all) and with lung function test parameters. Combined RV and RFVL PREFUL defect maps correlated with lung function testing (eg, with FEV r = -0.87 P < 0.05), and showed better regional agreement to Xe-MRI ventilation defects (Dice coefficient defect 0.413) with significantly higher VDP values (10.2 ± 27.3, P = 0.04) than either PREFUL defect map alone.
Combined RV and RFVL PREFUL defect maps likely increase sensitivity to mild airway obstruction with increased VDP values compared to Xe-MRI, and correlate strongly with lung function test parameters.
3 TECHNICAL EFFICACY STAGE: 2.
自由呼吸状态下区域流量容积环通气加权非对比增强质子肺MRI已成为评估区域肺通气的一项新技术，但尚未与氙气MRI（Xe-MRI）进行验证，Xe-MRI可直接显示健康志愿者、囊性纤维化（CF）患者和慢性阻塞性肺疾病（COPD）患者的通气情况。
比较非对比增强通气加权相位分辨功能肺MRI（PREFUL-MRI）测量的区域通气和区域流量容积环与Xe-MRI通气成像及肺功能测试参数。
回顾性研究。
20例COPD患者、8例CF患者和6名健康志愿者。
场强/序列：在1.5T下采集PREFUL和Xe-MRI梯度回波序列。
同一天采集PREFUL-MRI（自由呼吸）和Xe-MRI（单次屏气）的冠状位切片，根据腹背位置匹配并进行配准以进行评估。基于区域通气（RV）、区域流量容积环（RFVL）或Xe-MRI，采用两种不同阈值方法计算通气缺陷百分比（VDP）。计算RV和RFVL的联合VDP。此外，进行肺功能测试（如1秒用力呼气量[FEV]）。
使用Wilcoxon检验比较获得的参数，使用Spearman相关系数（r）进行相关性分析，并使用Bland-Altman分析和Dice系数评估PREFUL和Xe-MRI参数之间的一致性。
PREFUL和Xe测量的VDP与两种阈值技术均显著相关（r = 0.62 - 0.69，所有P < 0.05），且与肺功能测试参数相关。联合RV和RFVL的PREFUL缺陷图与肺功能测试相关（例如，与FEV r = -0.87，P < 0.05），并且与Xe-MRI通气缺陷显示出更好的区域一致性（Dice系数缺陷为0.413），VDP值显著更高（10.2 ± 27.3，P = 0.04），高于单独的任何一种PREFUL缺陷图。
与Xe-MRI相比，联合RV和RFVL的PREFUL缺陷图可能提高对轻度气道阻塞的敏感性，VDP值增加，并且与肺功能测试参数密切相关。
3 技术效能阶段：2。
