Cross-plane imaging. (A) Cross-plane imaging of the mitral valve by transthoracic echocardiography showing the user defined cut plane (dotted line and triangle) to show a short-axis view of the mitral valve (left panel) and the corresponding long-axis view (right panel). (B) Cross-plane imaging of mitral valve regurgitation which permits precise localization of regurgitant jets in the long-axis (left panel) and short-axis views (right panel). The cut plane is indicated by the blue triangle. LAX, long axis; SAX, short axis; LV, left ventricle; LA, left atrium; MV, mitral valve.