2001 ARRS Executive Council Award II - Fast three-point Dixon MR imaging using low-resolution images for phase correction: A comparison with chemicalshift selective fat suppression of pediatric musculoskeletal imaging

OBJECTIVE. The purpose of this study is to describe and to implement a new fast three-point Dixon MR imaging sequence with online image reconstruction , and to compare this sequence with conventional chemical shift selective ( CHESS) suppression of fat in pediatric musculoskeletal imaging SUBJECTS AND METHODS. A three-point Dixon technique using a fast spin-echo sequence with a new phase-correction algorithm providing online image recon struction was implemented on a 1.5-T scanner. Twelve pediatric patients and young adults were imaged with both the new three-point Dixon and conventio nal CHESS sequences. Three radiologists unaware of imaging parameters and c linical information independently scored the homogeneity of fat suppression and conspicuity of abnormality using a four-point system. An additional co mparison between the two techniques was made using a phantom. RESULTS. The three-point Dixon method showed superior fat suppression and l esion conspicuity (p < 0.001), particularly in the hands and feet, where CH ESS is prone to inconsistent fat suppression. The phantom study showed no s ignificant difference in the ratio of suppressed fat signal to background n oise and more homogeneous fat suppression using the three-point Dixon metho d. CONCLUSION. Compared with CHESS, the new fast three-point Dixon sequence wi th online image reconstruction provides superior fat suppression and lesion conspicuity and can be routinely used in pediatric musculoskeletal imaging .