Cardiac CT image of pulmonary artery bifurcation

Cardiac CT scan image at PA bifurcation

Cardiac CT scan image at the level of the bifurcation of the main pulmonary artery (MPA) into right pulmonary artery (RPA) and left pulmonary artery (LPA). Ascending aorta (AAo) and descending aorta (DAo) are seen as two contrast filled circles (cross section) anteriorly and posteriorly. Descending aorta is just to the left and anterior of the vertebra which is seen as a semicircular radio-opaque structure. Two elliptical radioluscent structures seen between the LPA and RPA are the left and right bronchi filled with air. This shows that the level of the section is below the tracheal bifurcation. As you go down, the bronchial images can be seen diverging (not seen in this single image). This is a good view to visualise pulmonary emboli in the main pulmonary artery or its proximal branches in cases of massive pulmonary embolism. Thrombi will be seen as filling defects in this contrast filled image. Aortic aneurysms can also be picked up in this view.