Head and neck: initial clinical experience with fast spin-echo MR imaging.

Fast spin-echo (FSE) is a new magnetic resonance (MR) imaging pulse sequence that employs echo trains of 180 degrees radio-frequency pulses to generate multiple refocused echoes during a single repetition-time interval. Phase encoding is reordered with the lowest spatial frequency views obtained in the echoes nearest the desired effective echo time. These techniques were used to examine 30 patients with pathologic conditions of the head and neck. The images were compared with closely matched conventional T2-weighted spin-echo (SE) images obtained during the same examination. Three unblinded readers evaluated 15 sets of both images for lesion conspicuity, motion artifact, diagnostic information, number of lesions seen, image quality, and sharpness of lesion borders. In all categories, FSE images were judged better than or equal to SE images, and in most cases FSE images were obtained in one-fourth to one-half the imaging time. In no case were lesions depicted on conventional T2-weighted SE images missed on FSE images; in fact, more lesions were seen on FSE images than on conventional T2-weighted SE images.