81 year-old man with history of NHL for evaluation of cardiac valve vegetation versus mass.

Figures 1 and 2: 3D GRE images demonstrate thickening of the inferior mitral valve annulus with decreased signal intensity and no contrast enhancement. This corresponds to coarse calcifications seen on both chest CT and echocardiogram.

Figure 3: Non-contrast chest CT image shows an area of coarse calcification of the inferior aspect of the mitral valve annulus.

Movie 1: Demonstrates a small amount of turbulence at the margin of the mitral valve leaflets during LV diastole. Mild aortic stenosis is present, evidenced by turbulent flow in the ascending aorta during systole.

Mitral valve annulus calcification.

Calcification of the mitral annulus is a degenerative process associated with aging. It occurs most commonly in women over 60 years of age. In addition to age, other risk factors include end stage renal disease, hypercalcemia, and hyperphosphatemia. Aortic stenosis, hypertension, hypertrophic cardiomyopathy, and diabetes mellitus have a higher incidence of mitral annulus calcifications.

Mitral annulus calcification starts as a focal process, affecting the posterior portion of the annular ring and then extends laterally and anteriorly. The process generally does not affect mitral valve function, but in severe cases can lead to regurgitation by interference with the systolic contraction of the mitral valve annulus. It can also lead to stenosis by impairing the opening of the mitral valve leaflets. The calcium deposits can penetrate deep into the myocardium to impinge on the conduction system and result in arrhythmias. Other complications include thromboembolism causing cerebrovascular accidents and bacterial endocarditis.

Plain chest radiographs may reveal an oval-shaped opacity just below the left atrial appendage, which represents the mitral annular calcific deposits. The aortic annulus is less commonly affected than the mitral annulus. The tricuspid annulus is rarely calcified, and only when associated with long standing pulmonary hypertension which results in chronically elevated right ventricular pressures.

References:

1. Miller SW. Cardiac Radiology: The Requisites, 1st edition. Mosby, 1996.
2. Cotran RS, Kumar V, Collins T, Robbins SL. Robbins Pathologic Basis of Disease, 6th edition. Saunders, 1999.
3. Pounder DJ. Calcification of the mitral annulus and its complications. American Journal of Forensic Medical Pathology. 1982 Jun; 3(2): 109-13.