Comparison between fast spin-echo and conventional spin-echo imaging of normal and abnormal musculoskeletal structures in children and young adults.

RATIONALE AND
OBJECTIVES: The differences in imaging characteristics between conventional and fast spin-echo studies of the skeletons of children and young adults were evaluated.
METHODS: Concurrent conventional and fast spin-echo studies of 23 patients were compared by measuring signal intensity, contrast, and, subjectively, conspicuity of normal and abnormal musculoskeletal structures.
RESULTS: Fast proton-density-weighted images had lower signal-to-noise ratios of muscle, fat, and physeal, epiphyseal, and articular cartilage. Using more than three echoes for proton-density images resulted in blurring and decreased lesion conspicuity. On fast T2-weighted images, there was greater conspicuity of normal cortex, ligaments, and muscle; but less contrast between fat and water because of a higher signal-to-noise ratio of fat. When both sequences were obtained with similar image quality, fast spin-echo was 40% faster.
CONCLUSION: Fast spin-echo studies allows faster imaging, but can have blurring on proton-density-weighted images and decreased fat-water contrast on T2-weighted images.