Fig. 12
From: Contrast opacification on thoracic CT angiography: challenges and solutions
Two images from a CTPE study obtained in a patient with tricuspid atresia and bidirectional cavopulmonary connection demonstrate poor opacification of right pulmonary artery and non-enhancement of left pulmonary artery (a). Findings could represent thrombus. Delayed images (90 s) demonstrate complete opacification of both pulmonary arteries and the intracardiac Fontan (b, also see Movie 2). In addition, notice the higher attenuation in the right superior and inferior pulmonary veins compared to the adjacent pulmonary artery. This is similar to contrast attenuation in SVC. Careful attention demonstrates mediastinal venous collaterals draining directly into the pulmonary veins forming an extra-cardiac right to left shunt