FAT-SUPPRESSION BY SATURATION OPPOSED-PHASE HYBRID TECHNIQUE - SPIN-ECHO VERSUS GRADIENT-ECHO IMAGING

The objective of the study was to compare hybrid opposed-phase fat sup pressed sequences using gradient-echo (GRE) and spin-echo (SE) techniq ues. Eight normal volunteers had abdominal imaging at 1.5 T using both an opposed-phase fat-suppressed SE sequence (TR/TE 450/14) and an opp osed phase GRE sequence (TE = 2.5) with frequency-selective fat suppre ssion. Signal to noise ratios (SNR) and contrast to noise ratios (CNR) relative to fat of pancreas, liver and paraspinal muscle were calcula ted for each sequence. The GRE sequence with TR of 150 (25 s breath-ho ld) significantly outperformed the corresponding 3 min SE sequence for SNR and CNR for all tissues (p < .05). Hybrid opposed-phase fat-suppr essed GRE sequences can be performed with breath-holding in less overa ll imaging time than SE sequences, and can achieve superior fat suppre ssion and signal-to-noise if sufficient TR is used.