Imaging techniques: Dissection of the aorta is a medicosurgical emerge
ncy whose prognosis has greatly improved with the development of relia
ble bedside diagnostic tools such as transthoracic and transesophageal
ultrasonography. Typical forms: The most common form involves the asc
ending aorta. These patients must be referred to a cardiac surgery uni
t as rapidly as possible. The aim of the surgical procedure is to repl
ace the ascending aorta due to the high risk of rupture and if possibl
e, resect the tear entry. Doubtful cases: Other explorations should be
requested in case of doubt. Computerized tomography, magnetic resonan
ce imaging or angiography may provide the diagnosis. The appropriate e
xploration depends on the patient's clinical status, transportability
and local equipment. (C) 1998, Masson, Paris.