Introduction: Cardiovascular MRI can provide detailed information on the function of the heart. However, characterizing normal function and morphology requires evaluation of large cohorts in relation to risk factors and environmental effects. This talk will give workshop participants an overview of current methods used to evaluate cardiac performance on a global and regional level. In particular, atlas based methods for quantifying variation between patient groups will be examined in relation to large scale studies including the Multi-Ethnic Study of Atherosclerosis and the UK Biobank.
Methods: The tomographic nature of MRI data lends itself to building 3D atlases of cardiac function. In the Cardiac Atlas Project, we have combined data from several sources to construct registered maps of regional cardiac function. These statistical atlases of shape and function enable automatic characterization of clinical shape and motion abnormalities.
Results: Atlas based methods have been used to examine the geometric differences due to gender, smoking habits, and hypertension. Males and African Americans tended to have larger hearts and females and Chinese tended to have smaller hearts for their height. Heart size increased with history of smoking or alcohol. Female hearts were more spherical than males, and Chinese were less spherical than Whites. Differences in sphericity were also found due to alcohol use (more spherical with current consumption), and presence of diabetes (more spherical with untreated diabetes) at end-systole. Partial least squares regression was also used to determine multidimensional shape changes in relation to clinical indices of remodelling.
Conclusions:
Cardiovascular MRI offers a variety of techniques for the evaluation of cardiac performance. The high accuracy and precision of MRI, combined with the ability to image all areas of the heart with equal fidelity and provide a variety of contrast mechanisms, have led to an increasing reliance on MRI in research and clinical studies.