Comparison of bolus- and filtering-based EIT measures of lung perfusion in an animal model. (3rd June 2019)

• Record Type: Journal Article
• Authors: Stowe, Symon; Boyle, Alistair; Sage, Michaël; See, Wendy; Praud, Jean-Paul; Fortin-Pellerin, Étienne; Adler, Andy
• Is Part Of: Physiological measurement. Volume 40:Number 5(2019:May)
• Publication Date: 2019-06-03
• Subjects: electrical impedance tomography -- lung perfusion -- ventilation; Physiology -- Measurement -- Periodicals; Patient monitoring -- Periodicals; 612
• DOI: 10.1088/1361-6579/ab1794
• Languages: English
• ISSNs: 0967-3334

Abstract

Abstract: Objective : Two main functional imaging approaches have been used to measure regional lung perfusion using electrical impedance tomography (EIT): venous injection of a hypertonic saline contrast agent and imaging of its passage through the heart and lungs, and digital filtering of heart-frequency impedance changes over sequences of EIT images. This paper systematically compares filtering-based perfusion estimates and bolus injection methods to determine to which degree they are related. Approach : EIT data was recorded on seven mechanically ventilated newborn lambs in which ventilation distribution was varied through changes in posture between prone, supine, left- and right-lateral positions. Perfusion images were calculated using frequency filtering and ensemble averaging during both ventilation and apnoea time segments for each posture to compare against contrast agent-based methods using Jaccard distance score. Main results : Using bolus-based EIT measures of lung perfusion as the reference frequency filtering techniques performed better than ensemble averaging and both techniques performed equally well across apnoea and ventilation data segments. Significance : Our results indicate the potential for use of filtering-based EIT measures of heart-frequency activity as a non-invasive proxy for contrast agent injection-based measures of lung perfusion.