A method of determining a biophysical model for a lung of a patient from multiple x-ray measurements corresponding to different breathing phases of the lung is provided. The method includes extracting multiple displacement fields of lung tissue from the multiple x-ray measurements corresponding to different breathing phases of the lung. Each displacement field represents movement of the lung tissue from a first breathing phase to a second breathing phase and each breathing phase has a corresponding set of biometric parameters. The method includes calculating one or more biophysical parameters of a biophysical model of the lung using the multiple displacement fields of the lung tissue between different breathing phases of the lung and the corresponding sets of biometric parameters.
