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

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‐DTPA2–. 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. Magn Reson Med 57:803–805, 2007. © 2007 Wiley‐Liss, Inc.