Division of Pulmonary, Critical Care, and Sleep Medicine, University of Miami, Miami, FL, USA.
, 4DMedical, Melbourne, Australia.
Respir Res. 2023 Aug 30;24(1):215. doi: 10.1186/s12931-023-02517-z.
X-ray velocimetry (XV) has been utilized in preclinical models to assess lung motion and regional ventilation, though no studies have compared XV-derived physiologic parameters to measures derived through conventional means.
To assess agreement between XV-analysis of fluoroscopic lung images and pitot tube flowmeter measures of ventilation.
XV- and pitot tube-derived ventilatory parameters were compared during tidal breathing and with bilevel-assisted breathing. Levels of agreement were assessed using the Bland-Altman analysis. Mixed models were used to characterize the association between XV- and pitot tube-derived values and optimize XV-derived values for higher ventilatory volumes.
Twenty-four healthy volunteers were assessed during tidal breathing and 11 were reassessed with increased minute ventilation with bilevel-assisted breathing. No clinically significant differences were observed between the two methods for respiratory rate (average Δ: 0.58; 95% limits of agreement: -1.55, 2.71) or duty cycle (average Δ: 0.02; 95% limits of agreement: 0.01, 0.03). Tidal volumes and flow rates measured using XV were lower than those measured using the pitot tube flowmeter, particularly at the higher volume ranges with bilevel-assisted breathing. Under these conditions, a mixed-model based adjustment was applied to the XV-derived values of tidal volume and flow rate to obtain closer agreement with the pitot tube-derived values.
Radiographically obtained measures of ventilation with XV demonstrate a high degree of correlation with parameters of ventilation. If the accuracy of XV were also confirmed for assessing the regional distribution of ventilation, it would provide information that goes beyond the scope of conventional pulmonary function tests or static radiographic assessments.
X 射线流速测量（XV）已被应用于临床前模型中，以评估肺运动和区域通气，但尚无研究比较 XV 衍生的生理参数与传统方法得出的参数。
评估荧光透视肺图像的 XV 分析与皮托管流量计通气测量之间的一致性。
在潮式呼吸和双水平辅助呼吸期间比较 XV 和皮托管衍生的通气参数。使用 Bland-Altman 分析评估一致性水平。混合模型用于描述 XV 和皮托管衍生值之间的关联，并优化 XV 衍生值以适应更高的通气量。
24 名健康志愿者在潮式呼吸期间接受评估，11 名志愿者在双水平辅助呼吸增加分钟通气量时重新接受评估。两种方法在呼吸频率（平均 Δ：0.58；95%置信区间：-1.55，2.71）或呼吸周期（平均 Δ：0.02；95%置信区间：0.01，0.03）方面均未观察到临床显著差异。使用 XV 测量的潮气量和流量低于使用皮托管流量计测量的值，尤其是在双水平辅助呼吸的较高容量范围内。在这些条件下，应用基于混合模型的调整来调整 XV 衍生的潮气量和流量值，以与皮托管衍生的值更接近。
XV 获得的通气放射性测量与通气参数具有高度相关性。如果 XV 对评估通气的区域分布的准确性也得到证实，它将提供超出传统肺功能测试或静态放射学评估范围的信息。
