This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Left cardiac border bulge can be sen in all, except 
Select and explain. 
A. Enlarged azygous vein, B. Left appendicular overgrowth, C. Coronary aery aneurysm, D. Pericardial defect
A: Enlarged azygous vein
Answer: A: Enlarged azygous vein 
Explanation: A i.e. Enlarged Azygous Vein Azygous vein is a right sided structureQ and all others are left sided. Azygous vein lies in the angle between the right main bronchus & trachea and size is < 10mm diameter on erect X-ray. Its size decreases on valsalva, in spiration; and increases in supine position, pregnancy, poal hypeension, IVC & SVC obstruction, right hea failure, constrictive pericarditis and enlarged subcranial nodes. So Azygous vein can't give rise to left cardiac bulge.