Quantification of Myocardial Effective Transverse Relaxation Time with Magnetic Resonance at 7.0 Tesla for a Better Understanding of Myocardial (Patho)physiology

Cardiovascular magnetic resonance imaging (CMR) has become an indispensable tool in the assessment of cardiac structure, morphology, and function. CMR also affords myocardial tissue characterization and probing of cardiac physiology, both being the focus of ongoing research. These developments are fueled by the move to ultrahigh magnetic field strengths, which permit enhanced sensitivity and spatial resolution that help to overcome the limitations of current clinical MR systems. This chapter reviews the potential of using CMR as a means to assess physiology in the heart muscle by exploiting quantification of myocardial effective transverse relaxation times (T2*) for a better understanding of myocardial (patho)physiology. For this purpose, the basic principles of T2* mapping, the biophysical mechanisms governing T2*, and (pre)clinical applications of myocardial T2* mapping are presented. Technological challenges and solutions for T2*-sensitized CMR at ultrahigh magnetic field strengths are discussed followed by a survey of acquisition techniques and post-processing approaches. Preliminary results derived from myocardial T2* mapping of healthy subjects and in patients at 7.0 Tesla are presented. A concluding section provides an outlook including future developments and potential applications.