Myocardial perfusion at 3 Tesla: A comparison to 1.5 Tesla with identical sequence parameters

Purpose: To implement myocardial first-pass perfusion imaging at 3 Tesla and to evaluate the potential benefit with regard to signal parameters in comparison to 1.5 Tesla using identical sequence settings and an intraindividual comparison.

Materials and Methods: In 16 volunteers, myocardial first-pass perfusion imaging was performed at 1.5 Tesla (Magnetom Avanto) and 3 Tesla (Magnetom TIM Trio) after injection of 0.05mmol/kg body weight Gadobutrol using an accelerated saturation recovery TurboFLASH technique (GRAPPA;R=2) at 1.5 and 3 Tesla. Detailed sequence parameters (TR 2.3ms, TE 0.93ms, FA 15°, BW 780Hz/px) as well as spatial resolution were kept identical for both field-strengths. Signal-to-noise ratio (SNR) and contrast enhancement rate (CER) were calculated from raw data SI-time curves. A linear fit on the upslope was performed for semiquantitative perfusion analysis.

Results: SNR was significantly higher at 3 Tesla than at 1.5 Tesla (35.7±11.9 vs. 18.0±5.5, p<0.001). CER was significantly greater at 3 Tesla than at 1.5 Tesla (2.2±0.9 vs. 1.5±0.5, p<0.001). Maximum upslope was significantly higher at 3 Tesla than at 1.5 Tesla (3.3±2.4 vs. 2.0±1.0, p<0.001).

Conclusion: 3 Tesla significantly improves CER and SNR compared to an identical sequence design at 1.5 Tesla. In addition, the most important semiquantitative perfusion parameter maximum upslope is significantly increased. This may allow for an improvement of spatial resolution and potentially for a better delineation of perfusion defects. Further studies though are necessary to potentially demonstrate a benefit of 3 T perfusion imaging in a clinical setting.