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Figure 4b.   Stress fracture of the second metatarsal shaft in a 19-year-old male runner. The patient had no history of acute trauma. (a) Axial T1-weighted MR image shows cortical thickening, a low-signal-intensity horizontal band representing a fracture line spanning the width of the bone (arrows), and adjacent low-signal-intensity changes within the marrow. (b) Coronal T2-weighted MR image shows increased signal intensity within the marrow and adjacent soft tissues (arrows). (c) On a gadolinium-enhanced fat-suppressed T1-weighted MR image, the fracture line is more conspicuous (arrows). Note the intense contrast enhancement of the adjacent bone marrow and soft tissues.