Computed tomography of stress fractures.

Twelve patients with stress fracture were examined by computed tomography (CT). Computed tomography appeared less sensitive than conventional radiographs in visualizing the cortical and periosteal changes. However, CT revealed endosteal callus formation of varying degrees even in cases with minor plain film findings. Two types of endosteal reaction were observed: a general endosteal thickening and a slight local bridge-formed callus. Density of the bone marrow cavity was increased in 10 cases. Soft tissue edema around the lesion was also seen, especially when the tibia was involved. The etiology of these findings is discussed, together with the differential diagnosis of malignant bone or soft tissue tumors.