Figure 108

T2WI in the same patient as Figure 10-7. A hyperintense area is clearly seen. In the center of that area a line of decreased signal—the fracture itself——is visible (black arrow).

area will appear hypointense, whereas on T2-weighted images (T2WI) that same region will appear hyperintense. This area will remain hyper-intense following fat suppression sequences. Over time, as the edema subsides, the hyperintense signal will disappear. When the fracture heals the region may remain hypointense or isointense with the rest of the vertebral body when the bone marrow fat has been restored (Figures 10-7 and 10-8).

Some patients with vertebral compression fractures, especially those around the thoraco-lumbar region, develop a cleft within the compressed vertebra. The cleft is usually located in the anterior-superior portion of the vertebral body, just beneath the superior endplate, and may contain air or fluid. Over time the margins of the cleft may calcify and become apparent on spinal radiographs, mostly in lateral views. It has been proposed that the clefts represent an unhealed, mobile and unstable compression fractures. The propensity of clefts to develop in the thoraco-lumbar region may be explained by the fact that this region withstands great dynamic loads that lead to vertebral instability and compromise fracture healing. It is now believed that Kummell disease, delayed post-traumatic avascular necrosis of the vertebral body, is similar in nature to clefted thoraco-lumbar compression fractures.

Sagittal reformatted CT images may help identify mild compressions by showing endplate depression and irregularity in the vertebral contour. CT can easily show violation of the posterior vertebral body wall in cases of burst fractures (Figures 10-9 and 10-10).

In patients with pathological compression fracture CT can detect even small lesions, which can then be biopsied under fluoroscopy or under CT guidance. MRI with contrast will help rule out metastatic disease, as the signal of the adjacent vertebral bodies will typically appear homogenous when the vertebral bodies are normal and heterogeneous when they are infiltrated by cancer.

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