Use of Diffusion-weighted Magnetic Resonance Imaging to Differentiate between Acute Benign and Pathological Vertebral Fractures: Prospective Study

WW Yao, MH Li, SX Yang, LL Zhu

Hong Kong J Radiol 2005;8:4-8

Objective: To evaluate the effectiveness of qualitative diffusion-weighted magnetic resonance imaging in differentiating between acute benign and pathological vertebral compression fractures.

Patients and Methods: A total of 71 patients with vertebral fractures, comprising 33 with benign fractures (18 traumatic and 15 osteoporotic) and 38 with pathological compression fractures (29 patients with metastasis, 4 with myeloma, 2 with eosinophilic granuloma, and 3 with tuberculosis), were examined by radiography and magnetic resonance imaging. T1-weighted, T2-weighted, short T1 inversion time (tau) inversionrecovery, diffusion-weighted, and gadolinium–diethylenetriamine penta-acetic acid– enhanced images were prospectively studied. Diffusion-weighted magnetic resonance imaging was performed using spin-echo echo-planar sequences. Pathological fracture was proven by biopsy or surgery, and benign compression fracture was proven by clinical or magnetic resonance imaging follow-up.

Results: Acute benign fractures and pathological fractures had characteristic appearances on standard magnetic resonance imaging. After diffusion weighting, 3 (9%) of the 33 benign fractures showed isointense or hypointense signal mixed with bands of hyperintensity, 8 (24%) were isointense or hypointense, and the remaining 22 (67%) displayed hyperintensity. Among the 38 pathological fractures, 35 (92%) had a hyperintense signal intensity on diffusion weighting, whereas the remaining 3 (8%) had a isointense or hypointense signals. There was no significant difference between acute benign fractures and pathological fractures with respect to hyperintensity after diffusion weighting (p = 0.098).

Conclusion: Qualitative diffusion-weighted magnetic resonance imaging cannot accurately distinguish pathological from acute benign vertebral compression fractures. Further quantitative diffusion-weighted magnetic resonance imaging studies may be needed.