Fig. 3
From: Doppler images of intra-pulmonary shunt within atelectasis in anesthetized children
Spectral Doppler analysis of the three types of vessels within the lung. Spectral Doppler analysis of a pulmonary artery (upper) and a bronchial artery (lower) within a representative anesthesia-induced atelectasis in 4-year-old patient. Spectral Doppler was performed during a brief expiratory pause. Pulmonary artery showed lower Doppler maximal velocity and higher resistance (IR) and pulsatile (IP) indexes than the bronchial artery presumably due to hypoxic pulmonary vasoconstriction