Fig. 20

Partial absence of the pericardium with herniation of the left atrial appendage. a Four-chamber view of the heart demonstrates a mass along the left heart border (arrowheads) adjacent to the left atrium (LA) and left ventricle (LV). A small amount of contrast material enters this mass. b Coronal view of the left atrium (LA) demonstrates that this mass (arrowheads) corresponds to the typical location of the left atrial applendage. Stagnant flow within the mass results in slow filling, but no thrombus was visible on delayed views. c Four-chamber view in a delayed phase demonstrates contrast filling of the mass. d Coronal view in a delayed phase also demonstrates homogeneous enhancement of the mass that represents a herniated and dilated left atrial appendage. e PA view of the chest demonstrates a bulge in the left cardiac contour. f Lateral view of the chest again demonstrates the mass corresponding to the herniated and enlarged left atrial appendage