Biatrial Enlargement on Chest X-Ray PA View

Transcript of the video: Chest X-ray PA view. You can see that there is straightening of left border. Normally, the main pulmonary artery segment will be concave and left atrial appendage region also will be not prominent. Here both have enlarged slightly, but not enough to produce gross bulges. So that is why we see straightening of left border, typically heard of in mitral stenosis with left atrial enlargement and mild pulmonary hypertension. When there is gross pulmonary hypertension, instead of these being straight over here, it will form a bulge over here. And when there is gross enlargement of left atrial appendage, that also will be forming a bulge over here. When there are bulges, aortic knuckle is first mogul, main pulmonary artery segment is second mogul, and left atrial appendage is taken as the third mogul sign. Here you can also see that the right atrium is enlarged, as the extent from the midline is more. That is the right atrial border. Right atrial enlargement. Normally right atrial border will be just along the right border of the spine. And if you look carefully, you can see the double atrial contour of left atrial enlargement. This is, you can carefully see here. There is difference in the density here and here. That is because of left atrium within the right atrial contour. That is shadow within shadow. Shadow within shadow is known as double atrial contour in biatrial enlargement. There is left atrium as well as right atrium. There are other features also to be looked for in such an X-ray. But the penetration of this X-ray is not good to show the other features like elevated left bronchus. There is some elevation seen here, but the view of the trachea and bronchi are not very clear. This is the trachea and this is probably the left bronchus and this is the location of the right bronchus. Those are not very clear in this picture. And this is the descending right pulmonary artery, which is also enlarged. And left pulmonary artery will be descending downwards like this. It is also not very clear, it has to be looked for within the cardiac silhouette. It is also not clear. This is the fundal gas bubble, indicating that the position is OK, that is, there is no situs inversus. This is the liver shadow.