MAC stands for which of the following?

• A. Mitral annular calcification
• B. Mitral area calcification
• C. Mitral valve annulus calcification
• D. Mitral atrial calcification

Answer: (A)

Mitral annular calcification is calcification of the fibrous ring that surrounds the mitral valve. On ultrasound, it appears as a bright, dense area along the mitral annulus, often near the posterior side, and may cause shadowing. This is the term most commonly used to describe this finding in echocardiography, making it the best choice. The other phrases aren’t standard or describe different structures: “mitral area calcification” isn’t a recognized term, while “mitral valve annulus calcification” would refer to the same anatomy but is not the common shorthand, and “mitral atrial calcification” would imply calcification in the left atrium rather than the annulus.