Lung air volume measurement from x-ray images using DSA technique

In this paper a new technique for measuring regional lung air volumes from two-dimensional propagation-based phase contrast x-ray (PBI) images at very high spatial and temporal resolution. Phase contrast dramatically increases lung visibility and the outlined volumetric reconstruction technique quantifies dynamic changes in respiratory function. These methods can be used for assessing pulmonary disease and injury and for optimizing mechanical ventilation techniques for preterm infants using animal models. For background-subtracted contrast-enhanced lung images, the bright and the spare signal allows unique identification of contrast thoracic cavity in the lungs. This represents an automatic filtering algorithm using such lung characterization for selecting lung phase images and mask images to generate a subtracted image. Thus, the exact image cannot be obtained using only the phase images and hence the comparison of mask image with the phase image produces the subtracted lung images. A control action is determined to eliminate a discrepancy, if any, between the predicted position and the measured air volume of the lungs. Thus the relative position of the imaging device and the biological structure is adaptively adjusted according to the control action to chase the motion of the lungs. This is implemented using LabVIEW programming.