What cardiac cause can cause this lung finding?
In this case, echo and TEE showed flail mitral leaflet causing asymmetric pulmonary edema.
Why is pulmonary edema from acute mitral valve regurgitation mostly right upper lobe predominant?
Because of the anatomical axis of the left ventricule and its high output, reflux of blood through the mitral valve in acute mitral valve regurgitation will preferentially head rightwards postero-superiorly thus causing venous engorgement mainly of the right superior pulmonary vein (which drains the right upper and middle lobes).
Right upper lobe ground glass alveolar opacity and air bronchogram sign. Differential diagnoses include blood, pus, water and protein.