Author:
Siddharthan Trishul,Grealis Kyle,Kirkness Jason P.,Ötvös Tamás,Stefanovski Darko,Tombleson Alex,Dalzell Molly,Gonzalez Ernesto,Nakrani Kinjal Bhatt,Wenger David,Lester Michael G.,Richmond Bradley W.,Fouras Andreas,Punjabi Naresh M.
Abstract
Abstract
Rationale
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.
Objectives
To assess agreement between XV-analysis of fluoroscopic lung images and pitot tube flowmeter measures of ventilation.
Methods
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.
Measurements and main results
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.
Conclusion
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.
Publisher
Springer Science and Business Media LLC