High-resolution MRI vs multislice spiral CT: which technique depicts the trabecular bone structure best?

The purpose of this study was to compare trabecular bone structure parameters obtained from high-resolution magnetic resonance (HRMR) and multislice computed tomography (MSCT) images with those determined in contact radiographs from corresponding specimen sections. High-resolution MR and MSCT images were obtained in 39 distal radius specimens. For HRMR the in-plane spatial resolution was 0.152x0.153 mm(2) with a slice thickness of 0.9 and 0.3 mm using a 3D T1-weighted spin-echo sequence. For MSCT the resolution was 0.247x0.247 mm(2) with a collimation of 1 mm. Using a diamond saw, 117 0.9- to 1-mm-thick sections were obtained from these specimens and contact radiographs were acquired. In the corresponding sections structure parameters analogous to bone histomorphometry were determined. Significant correlations between MR- and CT-derived structure parameters and those derived from the contact radiographs were found (p<0.01); r values of up to 0.75 were obtained for HRMR imaging and up to 0.70 for MSCT. On the average, structure parameters showed higher correlations for the MR- than for the CT-derived data. For the MR data the threshold algorithm used for binarizing the images substantially affected these correlations. In conclusion, trabecular bone structure parameters assessed in distal radius HRMR and MSCT images are significantly correlated with those determined in corresponding specimen sections (p<0.01). High-resolution MR-derived structure parameters, however, performed better in the prediction of trabecular bone structure.