Aberrant left brachiocephalic vein: CT imaging findings and embryologic correlation

Computed tomography was utilized to evaluate aberrant left brachiocephalic vein (ALBCV), an infrequently discussed congenital vascular anomaly among C hinese people. Associated vascular variation and possible embryonic correla tion are discussed. Since 1990, a total of 14 cases of ALBCV have been repo rted in patients receiving CT scan of chest, and was mainly an incidental d iagnosis. One case was confirmed angiographically and two others were confi rmed by magnetic resonance imaging. Emphasis was placed on the entry of the azygos vein into the superior vena cava (SVC), the length of the SVC, and the presence of other cardiovascular abnormalities. Of the 14 cases of ALBC V, the level of azygos vein entry was higher than the origin of the SVC in 7 cases 4 were approximately the same level and 3 were lower. The average l ength of the SVC was approximately 5.6 cm shorter than that of the general population, which is approximately 7.0 cm. Three cases had associated vascu lar anomaly. Most cases of ALBCV had azygos vein drainage level higher than or equal to the origin of the SVC. Right-sided aorta is one of the causes giving rise to the ALBCV during embryonic development. The CT scan remains a definitive diagnostic modality for ALBCV.