Vibration response imaging (VRI) technology, provides a radiation-free dynamic image of the lung, by visualizing vibration energy emitted during the respiration cycle (lung sounds). Airflow in the lungs during the respiration cycle creates vibrations that propagate through the lung tissue; these vibrations are affected by the structural properties of the lungs and may vary in space, time and frequency. Moreover, any structural alteration, such as a bronchial obstruction or space occupying infiltration, is reflected in a corresponding modification of the vibration response.