CT and MR Imaging Findings in Athletes with Early Tibial Stress Injuries: Comparison with Bone Scintigraphy Findings and Emphasis on Cortical Abnormalities1

Figure 3b. Images obtained in a 23-year-old male runner with 18-day history of worsening pain in left tibia and 9-day history of slight pain in right tibia. (a) Transverse 2-mm-thick high-spatial-resolution CT scan of left midtibia demonstrates 3-mm resorption cavity (arrow) in posterior diaphyseal cortex. Areas of osteopenia (arrowheads) can be seen in both the posterior and the anterior cortices. (b) Transverse 3-mm-thick fast STIR MR image (3600/60/150) confirms presence of resorption cavity containing tissue with high signal intensity (arrowhead). Osteopenia is appreciable as round and linear areas of intermediate signal intensity in anterior cortex (small arrows). In addition, irregularity of subperiosteal bone of same cortex is clearly seen. Also, endosteal edema (large arrow) is present. (c) Transverse 2-mm-thick high-spatial-resolution CT scan of right midtibia reveals a geographic area of osteopenia in posterior cortex (black arrowheads). Also, subperiosteal cortical irregularity can be seen (white arrowheads). A minor degree of osteopenia (arrow) is present in anterior cortex. MR images (not shown) did not demonstrate these abnormalities. (d) Posterior ^99mTc methylene diphosphonate scintigram shows slight uptake in posterior cortex of left tibial diaphysis (arrow). No abnormal uptake is visible in right tibia.