title: The effect of paraformaldehyde fixation on the delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) measurement.
abstract: The delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) method allows for both qualitative and quantitative measurement of the spatial distribution of glycosaminoglycan [GAG] in excised cartilage. The objective of this study was to determine the effect of paraformaldehyde fixation on dGEMRIC measurements. Five bovine and seven human cartilage pieces were punched into 5-mm plugs, fixed for 18 h in 4% paraformaldehyde solution, and washed. The magnetic resonance imaging (MRI) parameter T1 was measured prior and post fixation in cartilage without (T1(0)) and with (T1(Gd)), the ionically charged MRI contrast agent Gd(DTPA)(2-). Images of tissue before and after fixation were qualitatively very similar. The ratios of T1(0), T1(Gd), and calculated [GAG] after fixation, relative to before fixation, were near or slightly higher than 1 for both bovine cartilage (1.01 +/- 0.01, 1.04 +/- 0.02, 1.05 +/- 0.03, respectively) and for human cartilage (0.96 +/- 0.11, 1.03 +/- 0.05, 1.09 +/- 0.13). Thus, these data suggest that dGEMRIC can be used on previously fixed samples to assess the three dimensional spatial distribution of GAG.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors.forename: Arushi
authors.initials: A
authors.lastname: Dugar
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Farley
authors.forename: Angeline L
authors.initials: AL
authors.lastname: Wang
authors.forename: Mary B
authors.initials: MB
authors.lastname: Goldring
authors.forename: Steven R
authors.initials: SR
authors.lastname: Goldring
authors.forename: Bryan H
authors.initials: BH
authors.lastname: Swaim
authors.forename: Benjamin E
authors.initials: BE
authors.lastname: Bierbaum
authors.forename: Deborah
authors.initials: D
authors.lastname: Burstein
authors.forename: Martha L
authors.initials: ML
authors.lastname: Gray
mesh_terms: D000818:Animals; D002356:Cartilage / Q000737:chemistry*; D002417:Cattle; D005557:Formaldehyde / Q000494:pharmacology*; D005682:Gadolinium; D006025:Glycosaminoglycans / Q000032:analysis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011108:Polymers / Q000494:pharmacology*; D016707:Tissue Fixation
chemical_list: D006025:Glycosaminoglycans; D011108:Polymers; D005557:Formaldehyde; D005682:Gadolinium; C003043:paraform