The Importance of Cardiac Computed Tomography in the Diagnosis of Caseous Calcification of the Mitral Annulus-Case Reports

Abstract

Mitral annular calcification (MAC) is a common pathology of the mitral valve. In rare cases, calcifications occur in the mitral annulus degenerate serous; the caseous calcification of the mitral annulus (CCMA) then develops. Detection of CCMA is often random and requires differentiation from heart tumors or an abscess. The paper presents two cases of patients with ambiguous focal lesions of the mitral valve in echocardiography. In the first case, the cardiac computed tomography (CCT) showed a spherical, slightly irregular structure measuring approximately 33 × 22 mm, which was in contact with the posterior mitral valve leaflet from the lumen of the left ventricle. The lesion was heterogeneously intense, with an average density of about 500 HU and up to 975 HU on the periphery; it was not enhanced after the administration of a contrast agent. In the second case, the CCT revealed a heterogeneous, highly calcified structure in the peripheral zone and intermediate density in the central zone in the topography of the posterior mitral valve leaf, with dimensions up to about 41 × 31 mm in the plane of the valve leaflet, passing into the lumen of the left ventricle along its inferolateral wall to a depth of about 3.5 cm. In both cases, CCT enabled the diagnosis of CCMA. In conclusion, cardiac computed tomography may be decisive in the case of suspected caseous calcification of the mitral annulus where there is ambiguous echocardiography.

Keywords: cardiac computed tomography; caseous calcification of the mitral annulus; mitral annular calcification.

Figure 1

Patient No. 1. Caseous calcification of the mitral annulus (CCMA) in cardiac computed tomography. (A) Native phase. Axial reconstruction. The borders of the CCMA are marked in red. (B) Post-contrast phase. Axial reconstruction. The borders of the CCMA are marked in red. (C) Post-contrast phase. Secondary reconstructions. From the top and left side sequentially: MPR reconstruction, view in the short axis; MPR reconstruction, view in the long axis, 4-chamber; MPR reconstruction, view in the long axis, 2-chamber; VRT reconstruction. CCMA dimensions are marked with yellow lines and arrows; CCMA borders are marked in red.

Figure 2

Patient No. 2. Caseous calcification of the mitral annulus (CCMA) in cardiac computed tomography. (A) Native phase. Axial reconstruction. The borders of the CCMA are marked in red. (B) Post-contrast phase. Axial reconstruction. CCMA dimensions are marked with yellow lines and arrows; the borders of the CCMA are marked in red. (C) Post-contrast phase. Secondary reconstructions. From the top sequentially: MPR reconstruction, view in the short axis; MPR reconstruction, view in the long axis, 4-chamber; MPR reconstruction, view in the long axis, 2-chamber. CCMA borders are marked in red.