title: MR imaging near metallic implants using MAVRIC SL: initial clinical experience at 3T.
abstract: OBJECTIVE
  To compare the effectiveness of multiacquisition with variable resonance image combination selective (MAVRIC SL) with conventional two-dimensional fast spin-echo (2D-FSE) magnetic resonance (MR) techniques at 3T in imaging patients with a variety of metallic implants.
  
  
  METHODS
  Twenty-one 3T MR studies were obtained in 19 patients with different types of metal implants. Paired MAVRIC SL and 2D-FSE sequences were reviewed by two radiologists and compared for in-plane and through-plane metal artifact, visualization of the bone implant interface and surrounding soft tissues, blurring, and overall image quality using a two-tailed Wilcoxon signed rank test. The area of artifact on paired images was measured and compared using a paired Wilcoxon signed rank test. Changes in patient management resulting from MAVRIC SL imaging were documented.
  
  
  RESULTS
  Significantly less in-plane and through-plane artifact was seen with MAVRIC SL, with improved visualization of the bone-implant interface and surrounding soft tissues, and superior overall image quality (P = .0001). Increased blurring was seen with MAVRIC SL (P = .0016). MAVRIC SL significantly decreased the image artifact compared to 2D-FSE (P = .0001). Inclusion of MAVRIC SL to the imaging protocol determined the need for surgery or type of surgery in five patients and ruled out the need for surgery in 13 patients. In three patients, the area of interest was well seen on both MAVRIC SL and 2D-FSE images, so the addition of MAVRIC had no effect on patient management.
  
  
  CONCLUSIONS
  Imaging around metal implants with MAVRIC SL at 3T significantly improved image quality and decreased image artifact compared to conventional 2D-FSE imaging techniques and directly impacted patient management.
authors.affiliation: Department of Radiology, UCSF Medical Center, San Francisco, California.
authors.forename: Luis B
authors.initials: LB
authors.lastname: Gutierrez
authors.affiliation: Department of Radiology, VA Palo Alto, Palo Alto, California.
authors.forename: Bao H
authors.initials: BH
authors.lastname: Do
authors.affiliation: Department of Radiology, Stanford University Medical Center, 300 Pasteur Drive, Grant Building S062A, Stanford, CA 94305.
authors.forename: Garry E
authors.initials: GE
authors.lastname: Gold
authors.affiliation: Department of Radiology, Stanford University Medical Center, 300 Pasteur Drive, Grant Building S062A, Stanford, CA 94305.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Hargreaves
authors.affiliation: Department of Biophysics, Medical College Wisconsin, Milwaukee, Wisconsin.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Koch
authors.affiliation: GE Healthcare, Menlo Park, California.
authors.forename: Pauline W
authors.initials: PW
authors.lastname: Worters
authors.affiliation: Department of Radiology, Stanford University Medical Center, 300 Pasteur Drive, Grant Building S062A, Stanford, CA 94305. Electronic address: kate.stevens@stanford.edu.
authors.forename: Kathryn J
authors.initials: KJ
authors.lastname: Stevens
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D005260:Female; D006621:Hip Joint / Q000033:anatomy & histology*; D006622:Hip Prosthesis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008670:Metals; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D008670:Metals
keywords: MAVRIC SL; image quality; magnetic resonance imaging; metallic susceptibility artifact