Hip dGEMRIC in asymptomatic volunteers and patients with early osteoarthritis: The influence of timing after contrast injection

Abstract

Eight asymptomatic volunteers and 10 patients with early hip osteoarthritis (OA) were investigated with hip delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) at 30, 65, 100, and 135 min after IV injection with Gd-DTPA 2-. In asymptomatic volunteers there was a decrease in the dGEMRIC index (T1(Gd)) between 30 and 100 min. In patients the wash-in of Gd-DTPA2- was faster, with a low T1(Gd) at 30 min that did not change significantly over time. Therefore, earlier time points showed a larger separation in T1(Gd) between asymptomatic and OA hips, with more convenient timing logistics. However, T1(Gd) at 30 min had a larger standard deviation (SD) in the OA group, possibly due to variability of the steep slope of wash-in. This sensitivity to the imaging window may be less desirable for longitudinal studies in which reproducibility is a concern. At all time points, T1(Gd) was 20-30% lower in patients than in asymptomatic volunteers (P < 0.003), which demonstrates the sensitivity of dGEMRIC to early hip OA. © 2007 Wiley-Liss, Inc.