title: A method to identify implanted radiopaque markers despite rotation of the heart.
abstract: Radiopaque endocardial markers implanted by catheter are a useful tool for investigating cardiac function because one can follow the motion to a specific element to myocardium in three dimension. This motion is computed by recording each marker's X-ray shadow with a biplane radiographic system. It is necessary to identify which marker is which on both views to complete this computation. Rotation of the heart with respect of the X-ray system can change the pattern of markers so dramatically that one cannot identify each marker's shadow with confidence. We describe a method to predict where each marker's shadow will be on the X-ray images after the heart rotates, permitting identification of each marker in biplane radiographs, even after extreme changes in the heart's orientation.
mesh_terms: D000818:Animals; D002306:Cardiac Volume; D004285:Dogs; D006321:Heart / Q000000981:diagnostic imaging*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D009200:Myocardial Contraction; D011859:Radiography