059H Normal CT of the Heart FIRST STOPMax AP dimension of the LA in the region of the aorta. At this point the LA looks rectangularAshley Davidoff MD NORMAL VOLUME EVALUATION OF THE ATRIA AND VENTRICULAR CAVITIES ON A GATED CT SCANAxial images through the 4 chambers at the level of the A-V valves during diastole (mitral valve open) enables an approximate volume evaluation of the chambers. The atria are approximately the same volumes, and are about 1/3 the volume of the ventricles. The right ventricle (RV) is about 2/3 the volume of the left ventricle (LV)Ashley Davidoff MD Normal Left Ventricle (LV) of a 44 year old male in sagittal view. Note posterior position relative to the RVAshley Davidoff MD 131235 sagittal 001