Scintigraphic diagnosis of sacral fractures.

The H- or butterfly-pattern of uptake in the sacrum on Tc-99m-methylene diphosphonate bone scintigraphy is typical of fractures of the body of the sacrum that involve the sacral alae. This report describes four patients with a focal linear or curvilinear pattern of uptake in sacral fractures without alae involvement. This pattern differs from that associated with metastases in the sacrum, which typically has a random pattern. Recognition of this scintigraphic linear dot pattern of uptake in horizontal fractures in the inferior body of the sacrum is useful for detecting fractures without alae involvement that are not readily apparent on radiographs.