| الوصف: |
Objective To investigated morphological variability of VA origin and its entrance level into cervical transverse foramina by CTA. Methods To retrospectively investigated computed tomography angiograms (CTA) of 223 subjects (446 VA courses). Postprocessing of source images was performed by using a multi-planar reformation (MPR), maximum intensity projection (MIP), multi-planar reconstruction (MPR) and volume rendering (VR) algorithms. Investigated were origin of the VA and its level of entrance into vertebral transverse foramen with notification of the sex and side of variation. Results The VA entered the C6 transverse process in 92.60% of specimens (413 out of 446 VA courses, 64.57% males and 28.03% females). Abnormal entrance of VA was observed in 7.40% of specimens (33 VA courses), with the level of entrance into the C3, C4, C5, or C7 transverse foramen at 0.22%, 2.24%, 4.72% and 0.22% respectively. Comparably, we observed that the overall variability of abnormal origin of VA was 3.14% (7 out of 223 subjects), which LVAs all arose from aortic arch (AA). Comparing subgroups of subjects with normal and abnormal origin, there was significance difference in the frequency of entrance variation in the level of transverse foramen. Conclusion Abnormal entrance and origin of VA were observed in 7.40% and 3.14% of cases, which can be accurately appeared by CTA. |