MR Imaging of the Pancreas at High Field Strength

Comparison of Six Sequences

Abstract

The authors compared six MR sequences comprising conventional breath-hold [rapid spin echo (RASE) repetition time (TR) 240 ms/echo time (TE) 8 ms/90°, fast low angle shot (FLASH) 130/4.5/80, Turbo FLASH 6.5/3.5/ 8°], fat suppressed regular spin echo (FS SE 330/15/90°), and two combined fat suppressed breath-hold sequences (FS FLASH 130/8/80°, FS RASE 240/10/90°) for studying the normal pancreas. Sequences were selected on the basis of features desirable for demonstrating the pancreas, particularly absence or decrease in artifacts and improved dynamic range of intraabdominal tissue signal intensities. Ten normal voumteers were studied, six at 1.5 T and four at 1.0 T. and comparsion was made to regular short TR/TE SE Quantitiativ pancereas signal-to-noise (S/N) and pancreas fat-to-noise (SD/N) measurements and qualitative evaluation of overall resolution and artifacts were determined. Fat suppressed FLASH had the highest S/N (44.1 ± 10.8, p < 0.0001) and SD/N (35.0 ± 11.9, p < 0.0001), and seven studies were considered good or very good. Fat suppressed SE had good S/N (32.6 ± 7.7) and SD/N (19.0 ± 3.6), and eight FS SE studies were considered good or very good. Among the nonsuppressed sequences, FLASH had the best combination of quantitative and qualitative measurements. Our results suggest that fat suppression may be important for studying the pancreas and that nonsuppressed FLASH may be a reasonable alternative.