High Field Cardiac Magnetic Resonance Imaging

For a new technology, high-field cardiac magnetic resonance (CMR; 3.0 T≤B≤7.0 T) has come a long way. Not only has the number of reports referencing clinical applications risen,1,2 but prices for 3.0T systems have dropped almost 50% since the beginning of the millennium, and operational and service costs are virtually identical to those of 1.5T machines. New 3.0T installations make up about 25% of the total market share and are increasing at an annual growth rate of ≈10%. High field comprised ≈25% of the abstracts in CMR submitted to the most recent annual meetings of the Society for Cardiac Magnetic Resonance and the International Society for Magnetic Resonance in Medicine. Large-population studies targeting the heart are now being conducted at 3.0 T, including imaging within the framework of the German National Cohort.3 The advances in CMR at high magnetic field strengths foreshadow some of the potential benefits to be expected as the technology moves to ultrahigh fields (UHF; B≥7.0 T). The future of high-field CMR has obviously not ended at 3.0 T and is moving higher. Technical barriers are being addressed almost as fast as they appear. Clinical CMR at ultrahigh field strengths is rapidly underway.4–6 About 15% of sites already equipped with a 7.0 T magnetic resonance (MR) system have begun exploring UHF-CMR, with ≈50 peer-reviewed publications on human imaging. Early UHF-CMR applications include imaging and spectroscopy of the heart and large vessels.7–22 This can be achieved because of the inherent relationship between the signal-to-noise ratio (SNR) and magnetic field strength. In parallel, the field is making remarkable progress with respect to novel radiofrequency technologies20,23,24 and MR methods that should make clinical UHF-CMR feasible as 7.0 T MR machines become …