PMC8305068_01
Dynamic Evolution and Atypical Location of a Caseous Mitral Annular Calcification. LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.
gr1.jpg
PMC8305068_01_gr1.jpg
fig1
Furthermore, by evaluating former CT images, we were able to reconstruct the dynamic nature of a degenerative CMAC over a period of 19 years: initially, the anterior and posterior mitral annulus showed minimal calcifications (Figure 1, year 2001) that slowly but gradually progressed to a lumpy appearance. However, 10 years later, a small caseous part developed at the anterior annulus calcification (Figure 1, year 2011). Three years later, at TAVI-planning CT imaging, as discussed earlier, another increase of the lesion at the anterior mitral annulus was visualized, together with a continued significant decrease in its density (Figure 1, year 2014). CMAC consisted of a complete liquefaction necrosis surrounded by a delicate, partially calcified rim (Figure 1, year 2016). Current CT images from 2020 reveal the anterior part of this CMAC lesion to be reduced to small residues (Figure 1, year 2020), whereas the posterior annulus shows an increased calcified mass with small areas of central liquefaction.
PMC8305068_02
Caseous Mitral Annular Calcification at Cardiac Magnetic Resonance Imaging. (A) Basal short-axis slice of a T2-weighted turbo-spin-echo cardiac magnetic resonance imaging sequence. (B) Basal short-axis slice of a T1-weighted turbo-spin-echo cardiac magnetic resonance imaging sequence. (C) 4-chamber view of a cine steady-state free precession cardiac magnetic resonance imaging sequence. (D) 4-chamber view of a late gadolinium enhancement cardiac magnetic resonance imaging sequence. (E) Iodine contrast-enhanced electrocardiographically gated computed tomography (CT). (F) Contrast-free electrocardiographically gated CT.. Abbreviations as in Figures 1 and 2.
gr3.jpg
PMC8305068_02_gr3.jpg
fig3
Due to its CMR signal characteristics (i.e., general T2 hypointense signal [Figure 3A], a weak heterogeneous T1 hypointensity [Figure 3B], central hypointensity at cine steady-state free precession sequence with a brighter border [Figure 3C] evidencing a broad rim of late gadolinium enhancement [Figure 3D]), the differential diagnosis was an atypically located fibroma (usually characterized by homogenous late enhancement) or a CMAC with a prominent fibrous capsule. A subsequent electrocardiographically gated CT scan revealed a centrally hypodense mass with irregular calcified borders (Figure 3E) in continuity to a roughly calcified chronic myocardial scar (Figure 3F) at the territory of the circumflex artery.