This is the final output of the localization process. The two radio-opaque cables travel through or tightly straddle the target segment. The cables follow the path of a theoretical plumb line hanging from the center of the localizer (see the image below). This theoretical plumb line takes takes the place of the needle used in the needle localization technique.

Unlike needle localization, the spine localizer is non-invasive and provides excellent visualization of the cables even in morbidly obese patients, allowing the image contrast to be adjusted as necessary on PACS monitors to clearly visualize the vertebral segments.

Figure demonstrating the theoretical plumb line mentioned above. Reproduced by permission from Journal of Neurosurgery: Spine.