Computer-assisted analysis of radial symmetry in human airway epithelial cilia: Assessment of congenital ciliary defects in primary ciliary dyskinesia

The ultrastructural analysis of cilia and diagnosis of primary ciliary dysk inesia (PCD) in biopsies of airway epithelium is sometimes confounded by po or sampling, inconsistencies in tissue quality and processing, and other te chnical problems. Although clinical findings may lead to a presumptive diag nosis, ultrastructural analysis of ciliary axonemes is the standard for con firmation of PCD. The ultrastructural features of the cilium when viewed in cross section by transmission electron microscopy confer a radial symmetry to the axoneme. Current digital image processing techniques can be applied to such images to reinforce signal, diminish noise, and confirm consistenc y of position of axonemal structures, a process that can augment ultrastruc tural analysis for PCD. In this study, computer-assisted digital image proc essing was used to evaluate cross sections of cilia in airway epithelial bi opsies from patients previously diagnosed with PCD as well as in control su bjects with normal cilia. These studies supported the original diagnoses an d provided some new insights into axonemal organization in PCD. This techni que is simple and may be useful in providing a supporting means for confirm ing or ruling out a diagnosis of PCD in cases that appear equivocal.