This paper develops a 3D automated approach for airway wall segmentation and quantification in MSCT based on a patient-specific deformable model. The model is explicitly defined as a triangular surface mesh at the level of the airway lumen segmented from the MSCT data. The model evolves according to simplified Lagrangian dynamics, where the deformation force field is defined by a case-specific generalized gradient vector flow. Such force formulation allows locally adaptive time step integration and prevents model self-intersections. The evaluations performed on simulated and clinical MSCT data have shown a good agreement with the radiologist expertise and underlined a higher potential of the proposed 3D approach for the study of airway remodeling versus 2D cross-section techniques.