title: Differentiating normal hyaline cartilage from post-surgical repair tissue using fast gradient echo imaging in delayed gadolinium-enhanced MRI (dGEMRIC) at 3 Tesla.
abstract: The purpose was to evaluate the relative glycosaminoglycan (GAG) content of repair tissue in patients after microfracturing (MFX) and matrix-associated autologous chondrocyte transplantation (MACT) of the knee joint with a dGEMRIC technique based on a newly developed short 3D-GRE sequence with two flip angle excitation pulses. Twenty patients treated with MFX or MACT (ten in each group) were enrolled. For comparability, patients from each group were matched by age (MFX: 37.1 +/- 16.3 years; MACT: 37.4 +/- 8.2 years) and postoperative interval (MFX: 33.0 +/- 17.3 months; MACT: 32.0 +/- 17.2 months). The Delta relaxation rate (DeltaR1) for repair tissue and normal hyaline cartilage and the relative DeltaR1 were calculated, and mean values were compared between both groups using an analysis of variance. The mean DeltaR1 for MFX was 1.07 +/- 0.34 versus 0.32 +/- 0.20 at the intact control site, and for MACT, 1.90 +/- 0.49 compared to 0.87 +/- 0.44, which resulted in a relative DeltaR1 of 3.39 for MFX and 2.18 for MACT. The difference between the cartilage repair groups was statistically significant. The new dGEMRIC technique based on dual flip angle excitation pulses showed higher GAG content in patients after MACT compared to MFX at the same postoperative interval and allowed reducing the data acquisition time to 4 min.
authors.affiliation: MR Center-High field MR, Department of Radiology, Medical University of Vienna, Lazarettgasse 14, A-1090 Vienna, Austria. siegfried.trattnig@meduniwien.ac.at
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
authors.forename: Tallal C
authors.initials: TC
authors.lastname: Mamisch
authors.forename: Katja
authors.initials: K
authors.lastname: Pinker
authors.forename: Stephan
authors.initials: S
authors.lastname: Domayer
authors.forename: Pavol
authors.initials: P
authors.lastname: Szomolanyi
authors.forename: Stefan
authors.initials: S
authors.lastname: Marlovits
authors.forename: Florian
authors.initials: F
authors.lastname: Kutscha-Lissberg
authors.forename: Goetz H
authors.initials: GH
authors.lastname: Welsch
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D017690:Cell Transplantation / Q000379:methods; D019902:Chondrocytes / Q000378:metabolism / Q000637:transplantation*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006025:Glycosaminoglycans / Q000378:metabolism*; D006801:Humans; D051457:Hyaline Cartilage / Q000378:metabolism* / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D012965:Sodium Chloride; D023822:Tissue Engineering; D014182:Transplantation, Autologous; D014945:Wound Healing
chemical_list: D003287:Contrast Media; D006025:Glycosaminoglycans; D012965:Sodium Chloride; D019786:Gadolinium DTPA