Dissection examples

On the down an aortic dissection is seen with a large false lumen.
The compressed true lumen is seen on the inner side and is brighter than the false lumen.
Thrombus formation within the false lumen.
The true lumen usually is smaller as the false lumen wedges around the true lumen due to permanent systolic pressure.
The false lumen usually adheres to the outer curvature of the aortic arch, as is seen in this case. 

Type B Dissection