Pulmonary edema

Pulmonary oedema



The radiographic changes of hydrostatic oedema are quite characteristic. In the normal adult, the lower lobe pulmonary vessels are larger than the upper lobe vessels due to gravitational forces. As the left-sided pressure increases, the blood is diverted to the upper lobes. This results in "cephalization" with the upper lobe vessels becoming larger than the lower lobe vessels. As left heart pressure increases, fluid enters the peribronchovascular interstitium. As the interstitium becomes oedematous, the interlobular septa become prominent and the markings indistinct.  Pleural effusions are frequent in the more severe stages of left heart failure with a slight predominance to the right.