Figure 12d. Intramuscular hemangioma of the calf. (a) Sagittal T1-weighted MR image shows a soft-tissue mass with intermediate signal intensity relative to muscle, along with an overgrowth of fat (arrow) and punctate low-signal-intensity areas (arrowheads). (b) Radiograph demonstrates phleboliths (arrow), which account for the punctate low-signal-intensity areas seen at T1-weighted MR imaging. (c) Axial T2-weighted MR image demonstrates a high-signal-intensity lesion with septa (arrows). (d) High-power photomicrograph (original magnification, x400; H-E stain) demonstrates muscle fibers with proliferation of vessels of different sizes (arrows), along with prominent endothelium and adipocytes (arrowheads).