THE SHOULDER - ADAPTIVE MOTION CORRECTION OF MR-IMAGES

PURPOSE: To evaluate an adaptive-motion-correction technique to reduce global motion in shoulder magnetic resonance (MR) images. MATERIALS A ND METHODS: In the adaptive-motion-correction technique, interleaved n avigator echoes are used to provide a measure of view-to-view displace ment along the craniocaudal direction for each image echo in the acqui sition. The information is then retrospectively applied to the k-space data to correct for global shoulder motion. This algorithm was evalua ted in a series of 143 consecutive patient shoulder examinations by co mparing the original image set for each patient with the same image se t after retrospective correction by means of this algorithm. RESULTS: The average amplitude of craniocaudal motion was 1.4 mm. Image degrada tion due to motion was apparent in 100 (70%) of the 143 examinations. Application of the adaptive-motion-correction technique improved image quality in 73 (73%) of these 100 examinations or 51% of all 143 exami nations. CONCLUSION: Adaptive motion correction improved image quality in approximately three-quarters of the examinations in which motion w as present.