[Phased-array superficial coil and breath holding technique in MRI of the liver. Comparison of conventional spin echo sequences with rapid fat suppressing gradient echo and turbo-spin sequences].

PURPOSE

To determine the efficacy of fast MRI techniques using a tailored imaging design (breathhold and array-surface coil), conventional T1-, T2-weighted spin-echo (SE) sequences and breathhold gradient-echo (GRE) T1- and breathhold fast SE T2-weighted images were compared.

METHODS

20 patients with proven focal liver lesions were studied on a 1.5 Tesla system. Conventional SE T1- and T2-weighted imaging, as well as GRE T1- and fast SE T2-weighted imaging was performed. Fast imaging was done during breathhold using an array-surface coil. For all sequences signal-to-noise ratios (S/N) and liver-to-lesion-contrast ratios (L/L) were measured and statistically compared. In addition, two blinded readers qualitatively evaluated all images, using a score system regarding artifacts (breathing, pulsation), number of lesions, and over-all image quality.

RESULTS

Regarding image quality parameters, S/N and L/L, there was no significant (p > 0.05) difference between the conventional and fast imaging techniques. However, GRE imaging was superior (84.8%) to conventional imaging for breathing and pulsation artifacts, while fast SE T2 imaging was equal regarding breathing artifacts, but superior (51.5%) regarding pulsation artifacts. The number of detected hepatic lesions was identical in all sequences.

CONCLUSION

The fast MRI techniques demonstrated a superiority to conventional imaging regarding image quality and presence of artifacts. Therefore, fast imaging techniques can replace conventional techniques, at least in patients that can sufficiently sustain breathing.