A B1-insensitive high resolution 2D T1 mapping pulse sequence for dGEMRIC of the HIP at 3 Tesla.

Early detection of cartilage degeneration in the hip may help prevent onset and progression of osteoarthritis in young patients with femoroacetabular impingement. Delayed gadolinium-enhanced MRI of cartilage is sensitive to cartilage glycosaminoglycan loss and could serve as a diagnostic tool for early cartilage degeneration. We propose a new high resolution 2D T1 mapping saturation-recovery pulse sequence with fast spin echo readout for delayed gadolinium-enhanced magnetic resonance imaging of cartilage of the hip at 3 T. The proposed sequence was validated in a phantom and in 10 hips, using radial imaging planes, against a rigorous multipoint saturation-recovery pulse sequence with fast spin echo readout. T1 measurements by the two pulse sequences were strongly correlated (R2>0.95) and in excellent agreement (mean difference=-8.7 ms; upper and lower 95% limits of agreement=64.5 and -81.9 ms, respectively). T1 measurements were insensitive to B1+ variation as large as 20%, making the proposed T1 mapping technique suitable for 3 T.