Evaluation of Morphologic and Morphometric Characteristic of Foramen Transversarium on 3-Dimensional Multidetector...

To investigate the size and variations of the foramen transversarium (TF). In addition, to study the anatomical variations of the vertebral artery entering the transverse foramen of the cervical vertebrae.

The images of 141 (90 males, 51 females) patients aged 18-79 years (mean: 52.7 years) were analyzed. As a result, 987 cervical spines (C1-C7) and 1974 foramina transversaria were individually evaluated. Each TF"s anterior-posterior (AP) and transverse diameter (T) was measured bilaterally from multidetector computed tomography (CT) images. The absence of TF was considered as agenesis and a diameter of less than 2 mm as hypoplastic. Double foramina and incomplete double foramina were also noted. We evaluated the levels at which the vertebral arteries entered the transverse foramina.

The most frequent variation was duplication of TF, which was noted in a total of 88 (8.91%) cervical vertebrae. Agenesis of TF was seen in 37 (3.74%), and hypoplasia of TF in 26 (2.63%) cervical vertebrae. The vertebral artery entered into the transverse foramen of the 5th cervical vertebra from both sides in 4 (1.84%) patients. The vertebral artery entered into the transverse foramen of the 7th cervical vertebra in 4 (1.84%) patients. The vertebral artery entered into the transverse foramen of the 4th cervical vertebra in only 1 (0.45%) patient.

We believe that the determination of foraminal variations could be an important guide for neurosurgeons and radiologists in the diagnosis and treatment of diseases in this area.