MR of vertebral compression fracture: Acute and chronic trauma versus metastasis -emphasis on the signal intensity and enhancement-

Magnetic resonance (MR) imaging was performed in 41 patients with compression fracture of the spine. MR images of 14 patients with acute spinal trauma (within recent 1 month), eight patients with chronic trauma (over 1 month), and 19 patients with malignant cause without history for trauma were analyzed, retrospectively. Low signal intensities on T1-weighted images and high signal intensities on T2-weighted images were noted in 86% (12/14) of patients with acute trauma. Iso-signal intensities on all pulse sequence were noted in 50% (4/8) of patients with chronic trauma. Low signal intensities on T1-weighted images and high signal intensities on T2-weighted images were noted 100% (19/19) of patients with metastatic compression fracture. Contrast enhancement was observed in all the cases of acute trauma (4/4) and metastases (18/18), whereas only 20% (1/5) of chronic trauma showed enhancement. Fragmentation was seen in 35% (5/14) of patients with acute trauma, in 25% (2/8) with chronic trauma, and not seen in the patients with metastasis. In conclusion, acute traumatic compression fracture can not be differentiated from malignant cause by MR signal intensity or contrast enhancement, but chronic compression fracture can be distinguished from metastasis . Fragmentation may suggest traumatic compression fracture. So, MRI could be a useful method in differentiating the benign compression fracture from the pathologic ones caused by malignancy