Double Foramen Transversarium in Cervical Vertebra - Common and Important But Unreported Radiological-Anatomical Variant

Purpose: The Foramen Transversarium (FT) is a bony canal located in the transverse process of the cervical vertebra, FT contains the vertebral artery, veins and sympathetic nerve.

Since that the FT is occupied by vital vascular and neural structures, compression of the vertebral vessels and nerve may result in headache, migraine, fainting attacks and sometimes in hearing disturbances.

Detecting and reporting anatomical variations of the vertebral artery and the accompanying variations of the FT are essential and have clinical and surgical importance

Methods: We have examined a total of 250 random Cervical CT scans, in order to look for the prevalence and the frequency of reporting of this variation when present

Results: Out of 250 Cervical CT scans (ages between 2-93 years old, mean= 54 years old) the FT was found in 58 (23.2%) cervical CT scans, among them unilateral duplication was found in 24 (44.4%) vertebrae, and bilateral duplication was found in 37 (68.5%) vertebrae. In some of these scans (33%)we found DFT in more than one vertebral level, and in some patients we found bilateral DFT and unilateral DFT in another level in the same patient. Most of these variations of DFT (81%) were found in either C5 or C6 vertebra.

When reviewing the reports of these scans we found that all of these variations were not reported in any exam.

Conclusions: Although usually unreported in radiological reports, Double Foramen Transversarium is a common variation that should be reported due to its clinical significance.