Shabnam Mortazavi, Presenter: Nothing to Disclose

Mikko Nissi, Abstract Co-Author: Nothing to Disclose

John Hughes, Abstract Co-Author: Nothing to Disclose

Patrick Morgan MD, Abstract Co-Author: Nothing to Disclose

Jutta Ellermann MD, PhD, Abstract Co-Author: Nothing to Disclose

To assess if the presence of intra-articular Gd-DTPA2- in clinical MR arthrography significantly alters the T2* relaxation times of articular cartilage of the hip joint in patients with femoroacetabular impingement (FAI). 

The institutional review board (IRB) approved this study, and informed consents were obtained in this HIPAA compliant study. T2* mapping of ten patient volunteers (F/M: 7/3, age range 14-49, mean±SD = 33.0 ± 12.2 years) with symptomatic FAI was performed before and after diluted injection of intra-articular Gd-DTPA2- (final GD concentration of the injected mixture was 0.78 mmol/L). Overall 323 regions of interest (ROIs) were defined in acetabular and femoral cartilage each, pre- and post-Gd injection. Agreement of the relaxation times between pre- and post-Gd was assessed using Krippendorff’s alpha coefficient and linear regression through the origin.  

Pre- and post-Gd T2* relaxation times in both acetabular and femoral cartilage were found to strongly agree. Specifically, the estimated Krippendorff’s alphas were greater than 0.8 for both acetabular and femoral cartilage, indication strong agreement. Furthermore, linear regressions through the origin yielded estimated slopes very close to 1 and R2 values greater than 0.98, which implies that over 98% of the variation in post-Gd T2* is explained by the pre-Gd T2*.  

The presence of described intra-articular Gd-DTPA2- during clinical MR arthrography does not significantly alter T2* relaxation times of articular cartilage of the hip joint in patients with femoroacetabular impingment. 

It is safe to add a T2* relaxation time measurement in standard clinical arthrogram protocol utilizing dilute intra-articular injection of Gd-DTPA2-

Mortazavi, S, Nissi, M, Hughes, J, Morgan, P, Ellermann, J, T2* Relaxation Time of Acetabular and Femoral Cartilage with and without Intra-articular Gd-DTPA2- in Hip FAI Patients.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013927.html