PURPOSE: To determine the validity of the gadolinium dimeglumine(GdDTPA2-) enhanced magnetic resonance(MR) images by correlating to biochemical components especially glycosaminoglycans(GAG) content in the early detection of osteoarthritis. MATERIALS AND METHODS: Eight cadaveric knees were scanned to obtain pre-contrast T1 relaxation time using a 1.5T MR imaging unit. 7 hours after intra-articular injection of 40 ml of saline solution containing 4mM/L GdDTPA2-, MR images were obtained. Cartilages of the knee segments were removed from 14 sites of medial and lateral condyles of femur and tibia. Wet weight, dry weight, GAG content, and DNA content were measured. From the T1-weighted image series, T1 maps were generated. The T1 relaxation times of each part of the cartilage were compared with the results of the biochemical assay. RESULTS: The concentration of GdDTPA2- calculated from pre- and post-contrast T1 relaxation times was reverse-linearly related to GAG concentration. The R2 (square of correlation coefficient) was 0.684. The R2 for medial femoral condyle, lateral femoral condyle, medial tibial condyle, and lateral tibial condyle were 0.754, 0.639, 0.788, and 0.644, respectively. CONCLUSION: GdDTPA2- enhanced MR imaging can be used as a method of GAG imaging which has a potential for the early diagnosis of osteoarthritis.
Absorption* ; Cadaver* ; Cartilage ; Cartilage, Articular* ; DNA ; Early Diagnosis ; Femur ; Gadolinium ; Injections, Intra-Articular ; Knee* ; Magnetic Resonance Imaging ; Osteoarthritis ; Relaxation ; Sodium Chloride ; Tibia