Objective: The objective of this study was to compare measurements of semi-quantitative and pharmacokinetic parameters in areas of red (RBM) and yellow bone marrow (YBM) of the hip, using an in-house high-resolution DCE T1 sequence, and to assess intra- and inter-observer reproducibility of these measurements.
Methods: The right hips of 21 adult patients under 50 years of age were studied. Spatial resolution was 1.8 × 1.8 × 1.8 mm(3), and temporal resolution was 13.5 seconds. Two musculoskeletal radiologists independently processed DCE images and measured semi-quantitative and pharmacokinetic parameters in areas of YBM and RBM. Signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were calculated. Intra- and inter-observer reproducibility was assessed.
Results: Area under the curve (AUC) and initial slope (IS) were significantly greater for RBM than for YBM (p < 0.05). K(trans) and kep were also significantly greater for RBM (p < 0.05). There was no significant difference in time to peak between the regions (p < 0.05). SNR, CNR, and intra- and inter-observer reproducibility were all good.
Conclusions: DCE study of the whole hip is feasible with high spatial resolution using a 3D T1 sequence. Measures were possible even in low vascularized areas of the femoral head. K(trans), kep, AUC, and IS values were significantly different between red and yellow marrow, whereas TTP values were not.
Key points: High-spatial-resolution dynamic contrast-enhanced MRI of hip structures is feasible. Intra- and inter-observer reproducibility is good. Red and yellow bone marrow have different perfusion patterns.