CT Measurements
Patients were included only if they had retrospective, electrocardiography (ECG)-gated, MDCT prior to any mitral intervention. Readers used both 3D reconstruction and multiplanar reconstruction (MPR) to assess leaflet pathology, location, MVA, flail width/gap, anterior-posterior (AP) and commissural diameters, posterior leaflet length, maximal leaflet thickness (measured at A2/P2 region), presence of mitral valve cleft and degree of MAC.) Measurements were averaged and in cases of discrepancy between leaflet pathology/location, a 3rd CT reader was asked to evaluate as an independent ‘tie breaker.’ Leaflet pathology and location were assessed with a combination of volume rendered 3D and MPR views. The dimensions of the mitral annulus were calculated with MPR CT at end-diastole. Leaflet characteristics (flail width/gap, leaflet length and leaflet thickness) were calculated based on MPR. (Figure 2) Volume-rendered 3D imaging was used to assess if a cleft mitral leaflet was present. Degree of MAC was labeled as none, mild, moderate, or severe. Severity was calculated based on a previously published cardiac CT-based score [6].