Comprehensive cardiac magnetic resonance imaging at 3.0 tesla - Feasibility and implications for clinical applications

Objective: The objective of this study was to examine the applicability of high magnetic field strengths for comprehensive functional and structural cardiac magnetic resonance imaging (MRI). Subjects and Methods: Eighteen subjects underwent comprehensive cardiac MRI at 1.5 T and 3.0 T. The following imaging techniques were implemented: double and triple inversion prepared FSE for anatomic imaging, 4 different sets of echocardiographicgated CINE strategies for functional and flow imaging, inversion prepared gradient echo for delayed enhancement imaging, T1-weighted segmented EPI for perfusion imaging and 2-dimensional (2-13) spiral, and volumetric SSFP for coronary artery imaging. Results: Use of 3 Tesla as opposed to 1.5 Tesla provided substantial baseline signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) improvements for anatomic (T1-weighted double IR: Delta SNR = 29%, Delta CNR = 20%, T2-weighted double IR: Delta SNR = 39%, Delta CNR = 33%, triple IR: Delta SNR 74%, Delta CNR 60%), functional (conventional CINE: Delta SNR 123%, Delta CNR 74%, accelerated CINE: Delta SNR = 161%, Delta CNR = 86%), myocardial tagging (Delta SNRsystole = 54%, Delta CNRsystole = 176%), phase contrast flow measurements (Delta SNR = 79%), viability (Delta SNR = 48%, Delta CNR = 40%), perfusion (Delta SNR = 109%, Delta CNR = 87%), and breathhold coronary imaging (2-D spiral: Delta SNRsystole = 54%, Delta CNRRCA = 69%, 3-D SSFP: Delta SNRRCA = 60%, Delta CNRRCA = 126%), but also revealed image quality issues, which were successfully tackled by adiabatic radiofrequency pulses and parallel imaging. \\Conclusions: Cardiac MRI at 3.0 T is feasible for the comprehensive assessment of cardiac morphology and function, although SAR limitations and susceptibility effects remain a concern. The need for speed together with the SNR benefit at 3.0 T will motivate further advances in routine cardiac MRI while providing an image-quality advantage over imaging at 1.5 Tesla.