Differences in quantitative myocardial perfusion mapping by CMR at 1.5 T and 3 T.

Abstract

Quantitative myocardial perfusion mapping by cardiac magnetic resonance imaging (CMR) is an emerging non-invasive diagnostic tool for coronary heart disease. Advantages of quantitative analysis over traditional qualitative assessment include the objective assessment of myocardial blood flow in conditions of globally reduced flow such as coronary microvascular dysfunction [1]. Normal values for stress myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) have been established [2,3] and have been used for diagnostic validation, for example, against invasive functional tests for coronary microvascular dysfunction [4]. Thresholds have also been proposed for determining if a stress test is adequate (stress MBF >1.43 ml/g/min) [5] and whether there is obstructive coronary artery disease (stress MBF <1.94 ml/g/min) [6]. It is unclear however, whether field strength (3 T vs 1.5 T) has a significant impact on flow quantitation, and whether adjustments to the thresholds are required depending on the type of scanner used.