Magnetic resonance imaging of the heart: positioning and gradient angle selection for optimal imaging planes

Abstract

Electrocardiographically gated magnetic resonance images were acquired in 20 subjects using a spin-echo pulse sequence. For optimizing the display of cardiac anatomy, a technique was developed which uses patient positioning in addition to alteration of gradient angle to select image planes. High-quality images were acquired in three basic cardiac projections: (1) the long axis of the left ventricle, through the aortic valve and apex, parallel to the interventricular septum, (2) the long axis of the left ventricle, perpendicular to the septum, and (3) the short axis of the left ventricle at multiple levels including outflow, papillary muscle, and apex. Images of the aorta included axial images at multiple levels and long-axis images oriented to display the plane of the aortic arch. Images of these planes are easily achieved and, in contrast to standard images orthogonal to the chest wall, provide a reproducible and logical display of cardiac anatomy.

Influence of positional and angular variation of automatically planned short‐axis stacks on quantification of left ventricular dimensions and function with cardiovascular magnetic resonance

“…Dinsmore et al (17,18) demonstrated that optimal display and quantification of the cardiovascular system are achieved when the tomographic images are acquired in the planes aligned with the major anatomical axes of the heart. They also suggested that potential errors in evaluating global LV dimensions and function may arise due to oblique orientation of the imaging planes with respect to the myocardial wall, and deteriorating image quality in the subepicardial and subendocardial areas.…”

“…Optimal display and quantification of the heart are achieved in the planes orthogonal to the LV axis, or short-axis (SA) view (17,18). To deduce the oblique orientation of the LV axis with respect to the major anatomical axes of the thorax, intermediate acquisitions, such as the vertical (VLA) and horizontal (HLA) long axis, are usually acquired (17)(18)(19). Hence, planning of the anatomy with nontrivial spatial orientation and geometry is a laborintensive and knowledge-specific task.…”

Phase-offset technique to distinguish slow blood flow and thrombus on MR images

“…Images were acquired both in a short-axis projection, by using an image plane transverse to the thorax, and in a longaxis plane by using a technique that we have described previously [5,6]. ECG synchronization was accomplished by use of a telemetry system with three standard electrodes on the extremities with nonmagnetic lead wires.…”

Magnetic resonance imaging of the heart

“…Direct coronal and parasagittal imaging can be performed if additional information is needed about the origin of pulmonary artery and aorta (15). Useful planes for quantitating left ventricular wall thickness are projections along the long and short axis of the'left ventricle by changing the magnetic field gradient angle (16).…”