Neonates with congenital cardiac defects with decreased pulmonary blood flow.

Lesions that cause decreased pulmonary blood flow are those that obstruct the RVOT. In general, the radiographic presentation includes the following: (1) Thin, poorly visualized pulmonary blood vessels with little extension beyond the perihilar region; (2) Dark, hyperlucent lung fields; and (3) Moderate to severe cardiomegaly, depending on the cardiac defect(s) present.