Figure 51e

A. Type I aortic dissection. Characteristic appearance on chest roentgenogram (CXR). Note the marked dilatation of the ascending aorta. The aorta may appear normal on the CXR early in the course of aortic dissection.
B. Type III aortic dissection. In contrast to type I, marked distortion of the aortic arch and dilation of the descending portions are typical, as seen in this CXR of a patient with dissection beginning distal to the arch vessels.