All of the following are seen on the right side of the cardiac silhouette in chest X-ray except: September 2008, 2010
High-Yield Explanation
Ans. D: Pulmonary aery The cardiac silhouette is the most prominent central feature of the chest x-ray and it produces a familiar gourd shape with the apex of the left ventricle located just behind the left chest nipple. The inferior left ventricle wall lies on the left diaphragm and the superior base of the hea shows the aoic knob lying just to the left of the spine. A linear line descending from it, lying to the left of the spine, represents the lateral edge of the descending aoa. A normal cardiac silhouette is defined by the lower cross diameter of the hea from its right atrial boundary to the left ventricle apex occupying no more than one half the internal thoracic diameter. The right ventricular outflow tract (RVOT) at its junction with the left main pulmonary aery is concave. Right border of the hea in chest X-ray is formed by: Superior vena cava Right atrium Inferior vena cava