Christina A. Chen1, Weitian Chen2,
Stuart B. Goodman1, Brian A. Hargreaves1, Kevin M. Koch3,
Wenmiao Lu1, Anja C. Brau2, Christie E. Draper1,
Scott L. Delp1, Garry E. Gold1
1Stanford University, Stanford, CA,
United States; 2GE Healthcare Applied Science Lab, Menlo Park, CA,
United States; 3GE Healthcare Applied Science Lab, Milwaukee, WI,
United States
We
have developed 2 three-dimensional MRI prototypes that correct for
metal-induced artifacts, Slice Encoding for Metal Artifact Correction (SEMAC)
and Multi-Acquisition Variable-Resonance Image Combination (MAVRIC). In 10
knees with metallic total knee replacements (TKR) scanned at 1.5T, SEMAC and
MAVRIC both had significantly less artifact than conventional two-dimensional
fast spin echo (FSE). In a model of the knee fitted to a TKR of known
dimensions, SEMAC and MAVRIC had much smaller percent deviations from actual
component dimensions than FSE, indicating their accuracy in measuring geometry
in the presence of metal. MAVRIC and SEMAC are promising MR imaging
techniques that may allow for improved musculoskeletal follow-up imaging of
metallic implants and soft tissue structures surrounding metal in the knee.