Ventricular volume and mass by CMR.

Cardiovascular magnetic resonance (CMR) is an ideal technique for investigating the cardiovascular system, because it has excellent high resolution differentiation of myocardium from blood pool and lung, and is free from xrays and noninvasive. This combined with high levels of accuracy, – 4] and reproducibility, – 9] has made it very popular in the research arena for the assessment of ventricular volumes and mass. Ethical committees approve such scans with little hesitation, and small patient numbers are needed to prove hypotheses such as the effect of a new drug on remodeling. CMR is now considered the gold standard for such measurements. The techniques for applying CMR to the problem of assessing ventricular size and mass (volumetry) have been developed over many years, and earlier methods have been discarded because they compromised quality for speed, something which is not necessary in the fast scanning environment we enjoy in modern times. Thus, single or multislice spin echo techniques in the transaxial plane, or single and dual long axis cine techniques adopting geometric assumptions, will not be considered further. The technique that has won widespread acceptance is the short axis multislice (multiple 2D or 3D) cine acquisition, where both ventricles are sampled from the atrioventricular ring to the apex, with subsequent planimetry of the endocardial and epicardial borders of the ventricles to derive the required volume and mass parameters. The volumes obtained by this method are independent of geometric assumptions, which is a major advantage over 1D and 2D echocardiographic techniques. In this article describing this technique, the agreed nomenclature and display of planes of the heart is used as agreed by jointly published guidelines.