Fig. 3.

BF, biofilm; SH, probe sheath; RPS, radiopaque strip; and GI, ghost image; (a) $5000\times$ SEM image of 120-h postintubation endotracheal tube showing the presence of extracellular polymeric substrate; (b) $5000\times$ SEM image of same endotracheal tube in a different location; (c) $\mathrm{15,000}\times$ SEM of same endotracheal tube focusing in on a cluster of cells; and (d) corresponding OCT image.