Water-fat separation imaging of the heart with standard magnetic resonance bSSFP CINE imaging.

PURPOSE

To study balanced steady-state free precession CINE phase-sensitive water-fat separation imaging in four cardiac imaging planes to determine the necessary phase correction and image artifacts particular to this technique.

METHODS

Ten healthy volunteers and two subjects with known heart pathologies were studied with standard balanced steady-state free precession CINE imaging. Water-only and fat-only images were calculated using sign detection of the real part of the complex image after phase correction with constant and linear terms. Phase correction values were determined using both manual and automated methods. Differences in phase correction values between imaging planes, cardiac phases, coil elements, automated image reconstruction parameters as well as artifact scores between the automated and manual methods were studied with statistical tests.

RESULTS

Water-fat separation performed well in the heart after constant and linear phase correction. Both constant (p = 0.8) and linear x (p = 1) and y (p = 1) phase correction values did not vary significantly across cardiac phases, but varied significantly among the coils (p < 0.001) and imaging planes (p < 0.001). False water-fat separation artifacts were most frequent in the chest/back and also were present at the mitral and aortic valves.

CONCLUSION

Constant and linear phase correction is necessary to provide consistent results in standard imaging planes using a balanced steady-state free precession water-fat separation postprocessing algorithm applied to standard cardiac CINE imaging.