Abstract
It is a strongly desirable issue to know the information of actual blood flow direction and velocity in the left ventricle. Until now one could see the intraventricular flow as components of flow velocity vectors just toward and away from the transducer using conventional color Doppler imaging. However, using a novel technology, Vector Flow Mapping (VFM TM, Hitachi-Aloka Medical), blood flow velocity vectors and blood flow streamlines in the left ventricle could be visualized on the 2D images. For the VFM, one needs to obtain the blood velocity data toward and away from the transducer in left ventricular (LV) chamber using conventional Color Doppler imaging and also needs to know the LV endocardial wall motion velocity in the transverse direction using speckle tracking imaging. From these data, blood flow directions are computed using a polar continuity equation. Using the concept of VFM, vortices can be visualized in the LV chamber with the information of rotational direction. The strength of rotation can be calculated as vorticity. Typical VFM images in normal volunteers and patients with various kinds of cardiac diseases will be presented in the session.
