[Pathological features of atrial isomerism and its diagnosis by computed tomography].

Objective: To study the diagnostic significance of computed tomography (CT) in atrial isomerism.

Method: In one of the 2 cases of left atrial isomerism, abdominal CT scan with and without contrast enhancement were both performed, the other had plain thoraco-abdominal CT scan, and another case of right atrial isomerism received thoraco-abdominal contrast enhanced scan and thin-slice scan of the trachea. The diagnoses of all the 3 cases were surgically and pathologically confirmed.

Result: In the CT images of the 2 cases of left atrial isomerism, some typical features were identified including bilaterally symmetric bronchi, levoversion of the heart, horizontally positioned liver, absence of hepatic segment of the inferior vena cava and dilated azygos, short pancreas and double spleen, and mirror image isomerism of the major arteries and abdominal organs. The case of right atrial isomerism had bilateral upper lobe tracheal bronchus, mirror image isomerism of the heart and abdominal organs, short pancreas, translocation of the inferior vena cava to the left of the abdominal aorta, both of which were on the left of the spine.

Conclusions: CT have distinct diagnostic value in revealing thoraco-abdominal organs and major vessels, which can be crucial in the diagnosis and surgical management of patients with atrial isomerism.