The CT Diagnosis And The Clinical Significance Of Azygos Vein Abnormalities

ObjectiveTo observe the CT findings of the azygos vein and evaluate the clinical significance of azygos vein abnormalities.Methods200 cases without azygos vein abnomalities were randomly selected as the control group including 122 cases of male and 78 cases of female, in which there were no mediastinal tumor, cardiovascular disease and liver cirrhosis.121 cases of azygos vein abnormalities on enhanced chest CT were collected as the abnormal group(73 cases were male,48 cases were female).The diameter and enhanced modality in arterial phase of the azygos vein were measured and observed in control group. Apply SPSS 13.0 statistical software,using two independent sample t tests to compare the difference of azygos vein diameter between male and female and F tests to compare the difference in different age groups. Then analyzed abnormal CT manifestations and clinical significance of azygos vein in abnormal group.ResultsThe diameter of azygos vein in age group between 21 and 40 years was (0.72±0.25 cm), (0.83±0.29 cm) between 40 and 60 years and (0.82±0.30)cm over 60 years. There was no significant difference in sex groups, but statistical significance in age groups. The arch was filled with little contrast agent during the arterial phase in normal azygos vein, but it did not exceed the scope of distal lumen in azygos vein arch.121 cases of abnormal azygos vein can be divided into 3 types:variation of azygos vein(n=19, In which 2 case with expansion of azygos vein), azygos vein enlargement(n=66, In which 16 cases with expansion of azygos vein) and abnormal enhancement(n=54).ConclusionsWe suggest the diameter of azygos vein larger than 1.2 cm can be regarded as expansion in people over 40 years old, the azygos vein diameter larger than 1 cm in people between 20 and 40 years also can be regarded as expansion. The path anomalies of azygos vein or a number of azygos vein should be regarded as variation.The changes of abnormal azygos vein is secondary to a variety of diseases. The azygos vein enlargement are attributed to increased blood flow in the lumen and increased pressure in azygos vein while increased pressure in Superior vena cava and Superior vena cava obstruction result in azygos vein abnormal enhancement. Observation of azygos vein is benefical to detect the potential disease and to assess the severity of the lesions, it will also help avoid injury of the abnormal azygos vein during operation as well, radiologist should pay attention to it.