Application and diagnostic points of carotid artery ultrasound in the detection of internal carotid artery absence: Analysis of 16 cases and literature review.

Objective: To summarize the ultrasound diagnostic key points and imaging characteristics of absence of the internal carotid artery (ICA), and to explore the application value of carotid artery ultrasound in the diagnosis of ICA absence.

Methods: Sixteen patients diagnosed with ICA absence at our hospital were retrospectively analyzed. Clinical data, ultrasound images, and other relevant imaging data were reviewed. The ultrasound diagnostic key points and related imaging characteristics of ICA absence were summarized. Combined with a literature review, the application of carotid artery ultrasound in the diagnosis of ICA absence was discussed.

Results: Among the 16 patients, there were 10 males and 6 females ages ranging from 13 to 80 years. Among them, 5 patients had a history of cerebral infarction, 1 patient had a history of subarachnoid hemorrhage, and 10 patients had no history of stroke. Among the 16 patients, there were 10 left-sided lesions, 5 right-sided lesions, and 1 bilateral lesion. Three patients had concomitant aneurysms. Carotid ultrasound examinations in all 16 ICA absent patients revealed that a significantly slender common carotid artery (CCA) diameter compared to the contralateral (3.91 ± 0.73 vs. 6.92 ± 1.42, p < 0.001). On the side of ICA absence, the bifurcation of the carotid artery was not detected, with the CCA directly continuing as a single artery (external carotid artery, ECA). The temporal superficial artery percussion test was positive in all cases, and the blood flow spectrum of the single artery (ECA) on the side of the absent ICA showed a serrated pattern during diastole. On the side where the ICA was absent, the blood flow spectrum morphology of the CCA and ECA was consistent. Based on other relevant imaging examinations, the patients were classified into Lie types: A (10 cases), B (2 cases), C (1 case), D (1 case), and 2 cases were unclassified.

Conclusion: Carotid artery ultrasound has the advantages of easy operation, affordability, non-invasiveness, and capable of dynamic and high repeatability. Compared to other imaging examinations, it can provide more evidence for the diagnosis of ICA absence, and is suitable for widespread application and promotion.