Mitral stenosis – straightening of left border – X-ray chest PA view

Mitral stenosis – straightening of left border – X-ray chest PA view

Mitral stenosis – straightening of left border on X-ray chest PA view. The uppermost portion on the left cardiac border is the aortic knuckle. The next slight bulging is the main pulmonary artery and the left atrial appendage is seen below that. The prominent left atrial appendage is also called the third mogul sign, the first mogul being aortic knuckle and main pulmonary artery the second mogul. The latter two regions are usually concave and the obliteration of the concavity contributes to the “straightening of left border”.