The cardiac anatomy is complex, and cardiac structures have different appearances depending on the imaging plane. The most useful imaging planes are those parallel and perpendicular to the cardiac axes. The short axis (SA), vertical long cardiac axis (VLA - 2 chamber view - 2C) and horizontal long axis (HLA - 4 chamber view - 4C) are the standard views in cardiovascular imaging. The orientation of a heart is described relative to an imaginary line drawn from the base of the heart (valve plane) to the apex.
Obtaining cine images in these double-oblique planes requires the use of multiple localizing MRI sequences and knowledge of the cardiac anatomy. The long axis image plane is determined by the line that runs from the apex of the heart to a midpoint at the base of the heart, often taken to be midway between the mitral valve leaflets. The short axis is planned perpendicular to the long axis view.

A tomographic imaging direction, frontwards relative to a short axis of the human body from the back to the front.

A tomographic imaging direction, backwards relative to a short axis of the human body from the front to the back.

(LE) Myocardial late enhancement in contrast enhanced cardiac MRI has the ability to precisely delineate myocardial scar associated with coronary artery disease. Viability imaging implies evaluating infarcted myocardium to see whether there is enough viable tissue available for revascularization. The reversal of myocardial dysfunction is particularly relevant in patients with depressed ventricular function because revascularization improves long-term survival. In comparison to SPECT and PET imaging, myocardial late enhancement MRI demonstrates areas of delayed enhancement exactly in correlation with the infarcted region.
Viability on cardiac MRI (CMR) is based on the fact that all infarcts enhance vividly 10-15 minutes after the administration of intravenous paramagnetic contrast agents. This enhancement represents the accumulation of gadolinium in the extracellular space, due to the loss of membrane integrity in the infarcted tissue. This phenomenon of delayed hyperenhancement has been proven to correlate with the actual extent of the infarct.
MRI myocardial late enhancement can quantify the size, location and transmural extent of the infarct. If the transmural extent of the infarct (region of enhancement on MRI) is less than 50% of the wall thickness, there will be improved contractility in that segment following revascularization. In areas of hypokinesia, if there is a rim of "black" or non-infarcted myocardium that is not contracting well, it indicates the presence of hibernating myocardium, which is likely to improve after revascularization of the artery supplying that particular territory.
The total duration of a myocardial late enhancement MR imaging protocol for viability is approximately 30 minutes, including scout images, first-pass images, cine images in two planes, and delayed myocardial enhancement images. In order to assess viable myocardium, the gadolinium contrast agent is injected at a dose of 0.15 to 0.2 mmol/kg. After about 10 minutes, short axis and long axis views (see cardiac axes) of the heart are obtained using an inversion prepared ECG gated gradient echo sequence. The inversion pulse is adjusted to suppress normal myocardium. Areas of nonviable myocardium retain extremely high signal intensity, black areas show normal tissue.

For Ultrasound Imaging (USI) see Myocardial Contrast Echocardiography at Medical-Ultrasound-Imaging.com.

A plane or section not perpendicular to the xyz coordinate system, such as long and short axis views of the heart.