Radiological Signs of Mitral Stenosis

Key points

• • Mitral stenosis narrows the valve between the left atrium and the left ventricle, so blood backs up into the left atrium and the lungs.
• • The chest X-ray classically shows an enlarged left atrium, seen as a straightening of the left heart border and a double shadow behind the heart.
• • The raised pressure in the lung veins causes their upper branches to stand out, called upper-lobe blood diversion.
• • Fluid lines at the edges of the lower lungs (Kerley B lines) reflect the raised pressure in the lung vessels.
• • Long-standing disease can calcify the valve and enlarge the pulmonary arteries and the right side of the heart.