Delayed Gadolinium-Enhanced Magnetic Resonance Imaging (dGEMRIC) of Hip Joint Cartilage in Femoroacetabular Impingement (FAI): Are Pre- and Postcontrast Imaging Both Necessary?

The purpose of this study was to assess if delayed gadolinium MRI of cartilage using postcontrast T(1) (T(1Gd)) is sufficient for evaluating cartilage damage in femoroacetabular impingement without using noncontrast values (T(10)). T(1Gd) and Delta R(1) (1/T(1Gd) - 1/T(10)) that include noncontrast T(1) measurements were studied in two grades of osteoarthritis and in a control group of asymptomatic young-adult volunteers. Differences between T(1Gd) and Delta R(1) values for femoroacetabular impingement patients and volunteers were compared. There was a very high correlation between T(1Gd) and Delta R(1) in all study groups. In the study cohort with Tonnis grade 0, correlation (r) was -0.95 and -0.89 with Tonnis grade 1 and -0.88 in asymptomatic volunteers, being statistically significant (P < 0.001) for all groups. For both T(1Gd) and Delta R(1), a statistically significant difference was noted between patients and control group. Significant difference was also noted for both T(1Gd) and Delta R(1) between the patients with Tonnis grade 0 osteoarthritis and those with grade 1 changes. Our results prove a linear correlation between T(1Gd) and Delta R(1), suggesting that T(1Gd) assessment is sufficient for the clinical utility of delayed gadolinium MRI of cartilage in this setting and additional time-consuming T(10) evaluation may not be needed. Magn Reson Med 62:1362-1367, 2009. (C) 2009 Wiley-Liss, Inc.