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Purpose: To assess the feasibility of performing intra-articular dGEMRIC in patients scheduled for MR arthrography of the hip joint, specifically to evaluate whether using fixed amount of contrast agent and applying additional medications to joint cavity influence the dGEMRIC index. Materials and methods: Thirty-nine patients with hip pain, who had standard MR imaging of hip joint and longitudinal relaxation time (T1) mapping data following intra-articular administration of gadopentetate (Gd-DTPA2-) on either a 1.5T or 3.0T scanner, were reviewed. The T1s of articular cartilage and synovial fluid were analyzed with two-tailed t-test and regression analysis based on the presence or absence of morphological cartilage damage. A phantom study to mimic the synovial fluid changes during arthrography procedure was performed. Results: T1 measured in damaged cartilage was significantly lower compared to global T1 value of cartilage in the same joint at both 1.5T (p

Purpose: To evaluate if sub-regional analysis could offer higher sensitivity than full-thickness analysis when quantifying dGEMRIC data of the knee. Materials and methods: A dGEMRIC data set of medial femoral cartilage of the knee, including thirteen patients with osteoarthritis (diseased) and fourteen asymptomatic subjects (control), was reanalyzed with sub-regional analysis, i.e. using two ROIs (regions of interest) representing superficial region and deep region of the cartilage respectively, in addition to full-thickness ROI. Comparisons were made in T1pre (spin-lattice relaxation time without contrast administration), T1Gd (after Gd-DTPA2- administration), and ΔR1 (the change of relaxation rate) obtained with the three analysis methods. Results: Differences between superficial region and deep region in T1pre, and T1Gd were clearly observed. Superficial region analysis always provided shortest T1Gd and highest ΔR1 in both the diseased and the control, but the diseased-control difference in T1Gd and ΔR1 were quite close with the three analysis methods. Even though superficial region analysis showed slightly higher values of AUC (areas under the curves) of Receiver Operating Characteristic compared to full-thickness analysis, no significant difference in sensitivity was observed for knee dGEMRIC, with either T1Gd (p=0.802) or ΔR1 (p=0.328). Conclusion: For analyzing dGEMRIC of the knee with reduced cartilage thickness due to OA, there is no significant difference in sensitivity between sub-regional analysis and full-thickness analysis.

The objective of the present study was to utilize delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC), as a reflection of cartilage matrix integrity, to evaluate the effects of a specific hyaluronan, hylan G-F 20 (SYNVISC®; Genzyme Biosurgery, Cambridge, MA) in OA patients over the course of 6 months, and to utilize these data to determine effect size and power calculations for future studies. An open-label, single-blind exploratory study of patients having knee OA (Trail registration: NCT00949494) was performed in thirty subjects (20 active, intra-articular injections (3, week apart) with hylan G-F 20; 10 control). dGEMRIC data was obtained at baseline, 3 and 6 months. No changes were measurable with hylan administration under the clinical and imaging conditions utilized in the current study. The lack of response in the current study may be because the subjects had a relatively advanced stage of disease with respect to cartilage integrity.