Abstract: Objective  Magnetic resonance angiography (MRA) offers a non-invasive and radiation-free advantage in detecting and diagnosing intracranial artery stenosis; however, it is associated with high equipment costs. Transcranial color-coded Duplex ultrasound (TCCD) combined with contrast-enhanced ultrasound (CEUS) presents advantages such as non-invasiveness, real-time dynamic monitoring, and low cost. Nevertheless, there were no reports comparing the sensitivity, specificity, diagnostic agreement with MRA, or health economic evaluation of TCCD combined with CEUS for detecting major intracranial artery stenosis. Methods  From April 2023 to August 2024, a total of 55 patients suspected of having intracranial artery stenosis or occlusion were recruited at Beijing Tiantan Hospital, Capital Medical University. Both TCCD combined with CEUS and MRA were performed to evaluate the degree of stenosis in the terminal segment of the internal carotid artery, M1 and M2 segments of the middle cerebral artery, A1 and A2 segments of the anterior cerebral artery, P1 and P2 segments of the posterior cerebral artery, and the V4 segment of the vertebral artery. Intracranial artery stenosis was categorized into three groups: normal/mild, moderate, and severe/occlusion. Sensitivity, specificity, and consistency between the two methods were calculated. The Wilcoxon signed-rank test was used to compare the differences in examination costs and diagnostic time. Results  Fifty-five high-risk patients (110 cerebral hemispheres in total) with suspected cerebrovascular stenosis were included (median age: 46 years; 69.0% male). TCCD combined with CEUS and MRA were performed simultaneously. TCCD combined with CEUS showed high sensitivity and specificity in diagnosing intracranial artery stenosis, with good consistency compared to MRA. The highest diagnostic consistency was observed in the M2 segment (Kappa=0.704) and A2 segment (Kappa=0.650), while the M1 segment showed moderate consistency (Kappa=0.569). The average cost of TCCD combined with CEUS was 240 CNY with a diagnostic duration of 21 min, compared to 722 CNY and 287 min for MRA (P<0.001, effect sizer=0.89 － 0.91). Conclusion  Compared to MRA, TCCD combined with CEUS demonstrates higher consistency in screening for stenosis in the M2 segment of the middle cerebral artery and the A2 segment of the anterior cerebral artery. It is also more cost-effective. However, MRA has advantages in assessing deep intracranial vessels. A synergistic use of both methods can optimize the allocation of diagnostic resources for intracranial artery stenosis. It is recommended that primary healthcare institutions adopt TCCD as the initial screening tool, and, with standardized training and technical upgrades, combine it with CEUS. Complex cases should be referred for detailed evaluation by using MRA.

Key words: transcranial color-coded Duplex ultrasound, contrast-enhanced ultrasound, magnetic resonance angiography, intracranial arteries, health economics, treatment model