Pulmonary parenchymal manifestations of mitral valve disease.

Pulmonary parenchymal manifestations of mitral valve disease are the result of either pulmonary venous hypertension in mitral stenosis or abnormal regurgitant flow into pulmonary veins in mitral insufficiency. Typical radiographic findings in mitral stenosis include pulmonary vascular cephalization; interstitial, perivascular, and occasionally alveolar pulmonary edema; diffuse alveolar hemorrhage; hemosiderosis; and pulmonary ossification. Signs of interstitial pulmonary edema are frequently visible and include septal lines. Radiographic findings in diffuse alveolar hemorrhage consist of diffuse, confluent acinar or ground-glass areas of increased opacity, often sparing the peripheral parenchyma and creating the so-called window frame effect. Hemosiderosis is characterized by small, ill-defined nodules or by coarse reticular areas of increased opacity with a bias for the middle and lower lung regions. Ossification manifests as densely calcified, 1-5-mm nodules, mainly in the middle and lower lungs, with a tendency for confluence and the occasional presence of trabeculae. Imaging findings in mitral regurgitation depend on the acuteness of the disease. The most common parenchymal manifestations of acute mitral regurgitation are symmetric alveolar and interstitial pulmonary edema with indistinct, engorged pulmonary vessels and cephalized blood flow. Familiarity with these manifestations can expedite diagnosis, particularly in rare cases of unsuspected mitral valve disease.