The main planes used for cardiac imaging include two long axis views (the horizontal and vertical long axis) and the short axis view (Figure III2-1). The long axis is defined as the line that passes through the center of the mitral valve orifice and the left ventricular apex. For most studies, a series of short axis views are obtained from the left ventricular base, at the level of the mitral valve, to the apex. The three main planes are called orthogonal views because they are each perpendicular to each other. Depending on the orientation of the heart, each of these views is usually oriented obliquely to conventional axial, sagittal, and coronal planes. A systematic method for obtaining images in the correct planes is presented in the following subsections.

The process of obtaining images in the desired doubly oblique planes should take less than 2-3 minutes. For each step, a fast imaging sequence, similar to that used for scout imaging, should be used. This may consist of a fast spoiled gradient echo or balanced steady-state gradient echo (true FISP), or double inversion recovery single-shot fast spin echo sequence. For these sequences, imaging each slice requires 1 sec or less. It is important that the subject’s heart be in the same position for each step. Breath holding at end-expiration is generally preferable over breath holding at endinspiration. If the subject has limited breath-holding capacity, supplemental oxygen via nasal cannula should be provided.