The shape of the cord distortion resembles a scalpel blade, the 'scalpel sign' that suggests a dorsal arachnoid web. An often associated finding that is not present in this case is syringomyelia, thought to be due to alterations in CSF flow.

The imaging differential diagnosis would be ventral cord herniation or adhesion. When the cord is closely apposed to the anterior dura, these conditions can be difficult to differentiate.