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New MR imaging methods for metallic implants in the knee: Artifact correction and clinical impact
Author(s) -
Chen Christina A.,
Chen Weitian,
Goodman Stuart B.,
Hargreaves Brian A.,
Koch Kevin M.,
Lu Wenmaio,
Brau Anja C.,
Draper Christine E.,
Delp Scott L.,
Gold Garry E.
Publication year - 2011
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.22534
Subject(s) - magnetic resonance imaging , implant , artifact (error) , fast spin echo , medicine , biomedical engineering , nuclear medicine , radiology , surgery , computer science , artificial intelligence
Purpose: To evaluate two magnetic resonance imaging (MRI) techniques, slice encoding for metal artifact correction (SEMAC) and multiacquisition variable‐resonance image combination (MAVRIC), for their ability to correct for artifacts in postoperative knees with metal. Materials and Methods: A total of 25 knees were imaged in this study. Fourteen total knee replacements (TKRs) in volunteers were scanned with SEMAC, MAVRIC, and 2D fast spin‐echo (FSE) to measure artifact extent and implant rotation. The ability of the sequences to measure implant rotation and dimensions was compared in a TKR knee model. Eleven patients with a variety of metallic hardware were imaged with SEMAC and FSE to compare artifact extent and subsequent patient management was recorded. Results: SEMAC and MAVRIC significantly reduced artifact extent compared to FSE ( P < 0.0001) and were similar to each other ( P = 0.58), allowing accurate measurement of implant dimensions and rotation. The TKRs were properly aligned in the volunteers. Clinical imaging with SEMAC in symptomatic knees significantly reduced artifact ( P < 0.05) and showed findings that were on the majority confirmed by subsequent noninvasive or invasive patient studies. Conclusion: SEMAC and MAVRIC correct for metal artifact, noninvasively providing high‐resolution images with superb bone and soft tissue contrast. J. Magn. Reson. Imaging 2011;33:1121–1127. © 2011 Wiley‐Liss, Inc.