Mitral Valve Regurgitation Quantification From 3D Color Doppler Ultrasound - Standard of Care Data Collection

Inclusion Criteria: * both genders * age between 18 and 85 years old (adult, senior) * sinus rhythm * hHemodynamic stable * mitral valve regurgitation (MVR) of any grade i.e., from mild to severe as determined by assessment of a qualifying TransThoracic Echocardiography (TTE) exam at Saint-Luc University Hospital * scheduled for TransEsophageal Echocardiography (TEE) at Saint-Luc University Hospital, as part of the subject's routine standard of care * subjects has functional capacity to give written informed consent Exclusion Criteria: * pregnancy * subject lacks functional capacity to give written informed consent belongs to a vulnerable population per investigator's judgment or subject has any kind of disorder that compromises his/her ability to give written informed consent and/or to comply with study procedures Among the120 subjects, there will be three (3) sub-groups as follows: * a first sub-group (A) of 50 subjects with all inclusion criteria and none of the exclusion criteria * a second sub-group (B) of 50 subjects with additional inclusion criterion: scheduled for cardiac Magnetic Resonance (cMR), as part of the subject's routine standard of care * a third sub-group (C) of 20 subjects with additional inclusion criterion: scheduled for MitraClip transcatheter mitral valve repair (MitraClip) procedure as part of the subject's routine standard of care