Aortic dissection class 3: a little-known entity. Presentation of 4 cases

Aortic dissection (AD) is the most common acute condition of the aorta and has a high mortality. Therefore, it is a radiological emergency of vital importance. Currently, five subtypes are distinguished, among which AD class 3 -also known as limited or subtle AD- is the less recognised. This type of dissection is infrequent and needs to be acknowledged radiologically in order not to go unnoticed. Regarding its imaging features, this entity is characterized by a small focal bulging of the aortic wall outline and/or a limited round dilation at the region affected by the intimal tear. Recently, the low familiarity of the radiologist with this condition has been emphasized. With the aim of illustrating the main imaging findings of this entity and reviewing its most relevant aspects, we present four cases of AD class 3 diagnosed in our hospital.