Imaging of Caseous Mitral Annulus Calcification

Abstract

We present 2 cases of caseous mitral annulus calcification (MAC) in which one patient was asymptomatic whereas the second experienced left hemianopsia. Both patients underwent transthoracic and transesophageal echocardiography exams which revealed severe MAC with a mass consistent with caseous MAC. A mobile component of the caseous MAC was observed in the patient with left hemianopsia. Cardiac computerized tomography angiography confirmed the diagnosis. Considering the high surgical risk of caseous MAC debridement, both patients were treated conservatively with uneventful clinical follow-up.

Keywords: cardiac computed tomography angiography; caseous mitral annulus calcification; echocardiography.

Graphical abstract

Figure 1

Multimodality Images Case 1 is presented in A to I in which short-axis, 4-chamber, and 2-chamber views are shown, respectively, with (A to C) transthoracic echocardiography (TTE), (D-F) transesophageal echocardiography (TEE), (G) multiplanar reconstrication (MPR) noncontrast cardiac computed tomography angiography (CTA), and (H) arterial and (I) venous phases. TTE short-axis view at the mitral valve annulus (MA) level shows an inferior-posterior calcified mass (A, yellow arrow). The mass is extended towards the left atrium as shown in the 4-chamber view (B, yellow arrow) and 2-chamber view (C, yellow arrow). The surgical view on 3-dimensional TEE (D, yellow arrow) and 2-dimensional 4-chamber (E, yellow arrow) and 2-chamber view (F, yellow arrow) emphasize the irregularity of the mass while protruding to the left atrium. Multiplanar cardiac CTA images with noncontrast, arterial and venous phase, are presented in G, H, and I, respectively. In noncontrast images, the caseous mitral valve annulus calcification (MAC) is hyperattenuated with nonhomogenous calcification, especially seen in the edges of the mass. Note the relatively hypodense core. The caseous MAC protrude extends both towards left atrial and ventricle and was measured in arterial phase 22.7 × 20.7 × 25.5 mm (H). Enhancement is not seen in both arterial and venous phase (H, I). Case 2 is presented in J to Q in which short-axis, 3-chamber, and 4-chamber views are shown, respectively, with TTE (J to L), TEE (M and N), noncontrast MPR cardiac CTA (O), and arterial (P) and venous phases (Q). The TTE short-axis view of the left ventricle shows a caseous MAC extension toward the left ventricle (J, yellow arrow). The attached mobile portion is shown in K and L (yellow arrow) at 3-chamber and 4-chamber views, respectively. The TEE multiplanar 3-dimensional TEE measuring the mobile component of the caseous MAC (9 × 7 × 10 mm) and a ventricle view of it is shown in M (black arrow). A 2-dimensional TEE, 4-chamber view of the caseous MAC including the mobile mass is shown in N. Establishment of caseous MAC diagnosis with cardiac CTA is shown in O to Q. (O) Shows the nonhomogenous calcified MA mass (yellow arrow) with noncontrast images. Note the relatively hypodense core. The mobile mass is better defined with the contrast images (P, yellow arrow). No mass enhancement is observed in both arteria (P) and venous (Q) phases.