The complex structure and dynamic characteristics of the flows in respiratory airways remain challenges to the researchers to understand. The medical image-based computational modelling technique enables to reveal the complex flow behaviours in the patient-specific geometries. This talk aims to present a full-scale conducting airway model generated based on the high resolution CT images and the volume filling algorithm. The model illustrates the unstable respiratory flow patterns induced by the asymmetric geometry of physiological airways. I also would like to discuss the potentials, limitations and future goals of the current computational model development to support the clinical diagnoses and treatments.