Honda Sign on bone scan

It is characterized by vertical radiotracer uptake along both sacral alae connected by a horizontal line of uptake across the sacral body, forming an "H" configuration that resembles the Honda vehicle logo.

This finding is virtually pathognomonic for a sacral insufficiency fracture on a bone scan.

Known variants of this sign include the "half butterfly," "bar," and "tramline" patterns, depending on which parts of the "H" are absent or thickened.