Diffusion-weighted MR imaging of bone marrow: differentiation of benign versus pathologic compression fractures.

PURPOSE

To evaluate the usefulness of diffusion-weighted magnetic resonance (MR) imaging of bone marrow for differentiating between benign and pathologic vertebral compression fractures.

MATERIALS AND METHODS

Thirty patients with 39 vertebral compression fractures were examined with MR imaging. Diffusion-weighted MR imaging was performed with a steady-state free precession sequence in 22 acute benign osteoporotic and/or traumatic fractures and 17 pathologic compression fractures. Biplanar radiographs, T1-weighted spin-echo (SE) MR images, and short inversion time inversion-recovery (STIR) MR images were available for all patients. The signal intensity characteristics were analyzed qualitatively and quantitatively (bone marrow contrast ratios and signal-to-noise ratios) for all sequences.

RESULTS

At diffusion-weighted MR imaging, all benign vertebral compression fractures were hypo- to isointense to adjacent normal vertebral bodies. Pathologic compression fractures were hyperintense to normal vertebral bodies. Benign vertebral fractures had negative bone marrow contrast ratios at diffusion-weighted imaging, whereas pathologic vertebral fractures had positive values (P < .001). The difference in bone marrow contrast ratios for benign and pathologic compression fractures at T1-weighted SE and STIR imaging was not significant (P > .01).

CONCLUSION

Diffusion-weighted MR imaging provided excellent distinction between pathologic and benign vertebral compression fractures.