The role of computed tomography in the diagnosis of arterial gas embolism in fatal diving accidents in Tasmania.

Four cases of fatal diving accidents in Tasmania are presented, highlighting the role of CT in the investigation of diving fatalities. The CT technique allows rapid diagnosis when arterial gas embolism (AGE) is suspected. The traditional method of investigation, underwater autopsy, is a difficult procedure that requires specialized training in which the subtle diagnosis of AGE may be completely missed. Facilities for performing underwater autopsies are normally available only in tertiary referral centres, and therefore the diagnosis of AGE may be missed due to lack of facilities. The use of CT in the diagnosis of AGE in divers was first utilized in the early 1980s but has still not become widely adopted in forensic practice. This radiological technique has the advantage of being sensitive, quick, reliable, readily available and provides a permanent record. For hospitals that do not have a resident forensic pathologist, a CT scan can be easily performed and interpreted to eliminate the possibility of AGE. There are a number of pitfalls in the diagnosis of AGE with CT, particularly intravascular gas production following postmortem fermentation and off-gassing. Awareness of these pitfalls will help the radiologist in making a correct diagnosis of AGE.