dGEMRIC and Subsequent T1 Mapping of the Hip at 1.5 Tesla: Normative Data on Zonal and Radial Distribution in Asymptomatic Volunteers

Purpose: To characterize the zonal distribution of three-dimensional (3D) T1 mapping in the hip joint of asymptomatic adult volunteers. Materials and Methods: This study included 10 volunteers (3 males and 7 females with a mean age of 26.5 years; range, 24-31 years). MRI protocol included standard sequences for hip imaging and a dual-flip-angle 3D gradient-echo (GRE) sequence with volumetric interpolated breathhold examination (VIBE) postcontrast administration. Seven radial cuts were created clockwise around the femoral neck by using multi-planar reconstruction. Results: Analysis of the radial distribution revealed an Increase of T1-values toward the superior regions. T1-values differed between the peripheral and central portions. The standard deviation (SD) ranged from 76.2 ms to 124.1 ms in the peripheral zone, and from 69.1 ms to 112.9 ms in the central zone. In both zones, SD was low In the superior regions compared with the anterior and posterior regions of the joint. Based on the high intra(0.95) and interobserver (0.87) agreement, normative data from this study will prepare the foundation for further studies of dGEMRIC and T1 in the hip. Conclusion: We noted a radial T1 mapping pattern with higher values in the superior zone that was not statistically significant and a notable trend in zonal distribution between peripheral and central zones. These findings are critical while outlining future studies for detailed objective evaluation of zonal cartilage lesions due to varying pathologies.