Fig. 5
Results of the morphological analysis of single-energy volume CT scans between expiration and inspiration. a Example of the level of the whole-lung CT equivalent to that studied for the dynamic CT series, taken from an injured animal at PEEP 10 cmH2O. Overlaid is the cranio-caudal displacement of individual voxels in the slice demonstrating the majority of the displacement occurring in the middle third of the lung along the gravitational vector. b Example segmentation into 12 regions of equal height along the gravitational vector. c Quantification of the caudal displacement of the slice between expiration and inspiration in each of the 12 regions at different PEEP levels. Division into non-dependent, middle and dependent regions as per thick horizontal dashed lines in b. d The fraction of the slice that moves less than one slice (< 5 mm), between one and two slices (5–10 mm) and more than 2 slices (10–15 mm) in inspiration when grouped by PEEP. Points in c and d represent median and IQR of 4 injured and 4 uninjured animals