Detection of anomalous vertebral arteries by ultrasound as an alternative to radiological methods.

In order to examine 'ultrasound' approach in detecting the course of the vertebral artery (VA) and its anomalies important for neck surgery. An observational study with retrospective analysis of ultrasound images. 500 VAs on 250 3D CT angiographies and 500 ultrasound images performed on the same set of patients were analyzed. The relationship between the extraosseous portions of the VA to the neck organs with a special emphasis to the thyroid gland area, and the abnormal position of the VA were detected. Ultrasound and CT 3D images were compared. Ultrasound detected that 29 out of 500 VAs were anomalous (5.8%), 3D CT detected 30 cases. These anomalies were found in 22 patients (8.8%) (23 for 3D CT; 9.2%), in 7 (31.8%) of them bilaterally. An abnormal level of entrance (C3, C4, and C5) was observed in all anomalous cases. An additional case detected by 3D CT indicated C7 level of entrance. The ultrasound data correspond the CT data in 96.7% of cases. In ten cases (33.3%) the anomalous VA run close to the thyroid gland even touching the lower pole (16.7%; n = 5) or the upper pole (10.0%; n = 3) of the gland. In ten cases (33.3%) the anomalous VA crossed common carotid artery and the internal jugular vein by a way of a median loop. The incidence of anatomic variations of the VA is significant. Preoperative ultrasound investigation allows precise identification of anomalous VAs. Radiation-free ultrasound investigation of blood vessels is as precise as CT 3D imaging.