Caseous calcification of the mitral annulus – the complementary role of computed tomography and transthoracic echocardiogram

Abstract

PurposeCaseous calcification is a relatively uncommon variant of calcification of the mitral annulus. The purpose of the study was to assess characteristic radiological features of caseous calcification of the mitral annulus (CCMA) using computed tomography (CT) and compare the usefulness of CT and transthoracic echocardiogram (TTE) in a diagnosis of CCMA.Material and methodsSeventeen patients with CCMA, who underwent TTE and CT, were analysed. The following features of CCMA were evaluated: location, size, attenuation, enhancement after contrast administration, and margins.ResultsIn all cases TTE visualised an echo-dense structure with an irregular appearance involving the mitral valve annulus. In five cases the acoustic shadowing artefact was visible, and in four cases the mass contained central areas of echolucency. Eleven patients had valve disease.On CT CCMA appeared as a round mass in one case, in 10 cases as an oval mass, and in six patients it had a semilunar shape.In all cases on unenhanced CT, CCMA appeared as a hyperdense mass. On enhanced CT, CCMA in 10 cases (58.8%) had a hypodense centre, and in 7seven (41.2%) it had a hyperdense centre without enhancement after contrast administration. A hyperdense rim was observed in all cases except one patient.ConclusionsIn cases of the atypical appearance of CCMA on TTE, CT can lead to a definitive diagnosis. The combination of unenhanced CT and after IV contrast administration scans allows for recognition and distinction of CCMA from other pathologies, while TTE allows for assessment of additional valve dysfunction.

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

“…In both examinations, CCMA does not flow in the central zone in color Doppler and is surrounded by a hyperechoic structure [8]. When in doubt in the TTE, it is the CCT that leads to the final diagnosis [6]. In computed tomography, CCMA appears as a well-defined, oval or crescent-shaped, hypo-, iso-or hyperdense mass with peripheral calcifications of high Hounsfield units value, without contrast enhancement, usually located along the posterior mitral ring [6,8].…”

“…When in doubt in the TTE, it is the CCT that leads to the final diagnosis [6]. In computed tomography, CCMA appears as a well-defined, oval or crescent-shaped, hypo-, iso-or hyperdense mass with peripheral calcifications of high Hounsfield units value, without contrast enhancement, usually located along the posterior mitral ring [6,8]. In case of doubt, and when CCT is still inconsistent with a diagnosis, cardiac magnetic resonance is the technique of choice.…”

“…It rarely occurs in younger patients-e.g., in people with Barlow's disease [4] and Marfan's syndrome [5]. It is currently estimated that it affects 0.068% of the general population and 0.64% of all MAC cases [6].…”

Association between calcification of mitro-aortic continuity and mitral regurgitation in patients undergoing transcatheter aortic valve replacement

“…Mitral annular calcification (MAC) occurs as a result of a chronic degenerative process of the fibrous support structure of the mitral valve. MAC is present in approximately 8-15% in the general population, more often in women [1,2,3]. MAC commonly coexists with aortic stenosis (AS) [4,5] and may have similar etiology and pathophysiological mechanism [6,7].…”

Answer to Quiz: Echo Imaging on Page 79 and Case Discussion

“…In conclusion, it is necessary to stress that caseous MVA calcification is not a commonly recognized entity and may mimic heart masses. This type of annular calcification has a characteristic radiological appearance allowing differentiation from much often seen non-caseous type (11)…”