title: T2* relaxation time of acetabular and femoral cartilage with and without intraarticular gadopentetate dimeglumine in patients with femoroacetabular impingement.
abstract: OBJECTIVE
  The purpose of this study was to assess whether the presence of intraarticular gadopentetate dimeglumine during clinical MR arthrography significantly alters the T2* relaxation time of hip articular cartilage in patients with femoroacetabular impingement.
  
  
  METHODS
  T2* mapping of 10 patient volunteers (seven female patients, three male patients; age range, 14-49 years; mean, 33.0 ± 12.2 [SD] years) with symptomatic femoroacetabular impingement was performed before and after intraarticular administration of gadopentetate dimeglumine. Overall 323 ROIs were defined in each acetabular and femoral cartilage before and after gadolinium injection. Agreement of the T2* relaxation times before and after gadolinium injection was assessed with the Krippendorff alpha coefficient and linear regression through the origin.
  
  
  RESULTS
  T2* relaxation times before and after gadolinium injection in both acetabular and femoral cartilage were found to agree strongly. Specifically, estimated Krippendorff alpha values were greater than 0.8 for both acetabular and femoral cartilage, linear regressions through the origin yielded estimated slopes very close to 1, and R(2) values were greater than 0.98.
  
  
  CONCLUSIONS
  The results indicate that intraarticular injection of gadopentetate dimeglumine according to the protocol described in this study has little effect on the T2* of femoral and acetabular cartilage. The results suggest that T2* mapping can be safely performed as an addition to a standard clinical hip imaging protocol that includes gadopentetate dimeglumine administration.
authors.affiliation: 1 Department of Radiology, University of Minnesota, 2021 Sixth St SE, Minneapolis, MN 55455.
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Nissi
authors.forename: Shabnam
authors.initials: S
authors.lastname: Mortazavi
authors.forename: John
authors.initials: J
authors.lastname: Hughes
authors.forename: Patrick
authors.initials: P
authors.lastname: Morgan
authors.forename: Jutta
authors.initials: J
authors.lastname: Ellermann
mesh_terms: D000077:Acetabulum / Q000473:pathology; D000293:Adolescent; D000328:Adult; D002358:Cartilage, Articular / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D057925:Femoracetabular Impingement / Q000473:pathology*; D005269:Femur / Q000473:pathology; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006621:Hip Joint / Q000473:pathology*; D006801:Humans; D007270:Injections, Intra-Articular; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: MRI; T2*; acetabular cartilage; femoroacetabular impingement; gadolinium; hip