Accurate measures of regional lung air volumes from chest X-rays of small animals

• Main Authors: O'Connell, D. W, Morgan, K. S, Ruben, G, Croton, L. C. P, Pollock, J. A, Croughan, M. K, McGillick, E. V, Wallace, M. J, Crossley, K. J, Pryor, E. J, Lewis, R. A, Hooper, S. B, Kitchen, M. J
• Format: Journal Article
• Language: English
• Published: 07-04-2022
• Subjects: Physics - Medical Physics
• DOI: 10.48550/arxiv.2202.08072

We present a robust technique for calculating regional volume changes within
the lung from X-ray radiograph sequences captured during ventilation, without
the use of computed tomography (CT). This technique is based on the change in
transmitted X-ray intensity that occurs for each lung region as air displaces
the attenuating lung tissue. Lung air volumes calculated from X-ray intensity
changes showed a strong correlation ($R^2$=0.98) against the true volumes,
measured from high-resolution CT. This correlation enables us to accurately
convert projected intensity data into relative changes in lung air volume. We
have applied this technique to measure changes in regional lung volumes from
X-ray image sequences of mechanically ventilated, recently-deceased newborn
rabbits, without the use of CT. This method is suitable for biomedical research
studies and shows potential for clinical application.