Enlarged azygos vein

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An enlarged/dilated azygos vein may result from a number of physiological as well as pathological causes. The enlarged azygos vein may be seen as a widened right paratracheal/paraspinal stripe on a frontal chest radiograph.

Causes for dilatation

There are a number of physiological causes for enlargement of the azygos vein such as pregnancy and over hydration, but most cases are pathological:

~~azygous~~azygos continuation of the inferior vena cava (IVC)
~~aorto-azygous~~aortoazygos fistula ¹
congestive heart failure (CHF)
constrictive pericarditis
congenital SVC interruption (distal to ~~azygous~~azygos entry)
SVC obstruction (distal to ~~azygous~~azygos entry ³)
~~congential~~congenital IVC interruption
IVC obstruction
pericardial effusion
portal hypertension
right ventricular strain
tricuspid insufficiency

Differential diagnosis

The differential diagnosis depends on the radiographic study being reviewed; on a CXR, the differential includes:

~~-<li><a href="/articles/azygous-continuation-of-the-inferior-vena-cava-ivc">azygous continuation of the inferior vena cava (IVC)</a></li>~~
+<li><a href="/articles/azygous-continuation-of-the-inferior-vena-cava-ivc">azygos continuation of the inferior vena cava (IVC)</a></li>
~~-<a href="/articles/aortoazygous-fistula">aorto-azygous fistula </a>1~~
+<a href="/articles/aortoazygous-fistula">aortoazygos fistula </a>1
~~-<a href="/articles/congenital-svc-interruption">congenital SVC interruption </a>(distal to azygous entry)</li>~~
+<a href="/articles/congenital-svc-interruption">congenital SVC interruption </a>(distal to azygos entry)</li>
~~-<a href="/articles/superior-vena-cava-obstruction">SVC obstruction</a> (distal to azygous entry 3)</li>~~
~~-<li><a href="/articles/congential-ivc-interruption">congential IVC interruption</a></li>~~
+<a href="/articles/superior-vena-cava-obstruction">SVC obstruction</a> (distal to azygos entry 3)</li>
+<li><a href="/articles/congential-ivc-interruption">congenital IVC interruption</a></li>

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Enlarged azygos vein

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Causes for dilatation

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