The role of contrast-enhanced transcranial color-coded real-time sonography combined with the common carotid artery compression test in preoperative evaluation of anterior communicating artery patency in patients with insufficient temporal bone windows.
Liu Y, Zheng S, et al. • Frontiers in neurology • 2026
CE-TCCS combined with the CCC test can serve as a reliable technique in preoperative evaluation of ACoA patency in patients with inadequate temporal bone windows, yielding 94.67% sensitivity, 100% specificity, and 95.65% overall diagnostic accuracy compared to CTA.
Key Findings
Results
CE-TCCS significantly improved visualization rates of intracranial circle of Willis structures compared to standard TCCS in patients with suboptimal temporal bone windows.
Study population: 116 patients with suboptimal temporal bone windows and symptomatic carotid artery stenosis scheduled for carotid endarterectomy
Visualization rates of anterior cerebral artery, middle cerebral artery, and posterior cerebral artery were all significantly improved with CE-TCCS compared to TCCS alone (p < 0.001)
The prospective design allowed direct within-patient comparison of TCCS versus CE-TCCS display rates
Results
CE-TCCS combined with the common carotid artery compression test demonstrated excellent diagnostic accuracy for anterior communicating artery functional patency compared to CTA as the anatomical reference standard.
Assessment was performed in 92 patients after 24 patients were excluded due to unilateral absence of the ACA-A1 segment on CE-TCCS
CE-TCCS combined with CCC test showed no significant difference from CTA (p = 0.125)
Consistency with CTA was excellent: Kappa = 0.868 (95% CI: 0.743–0.993, p < 0.001)
Results
Standalone CE-TCCS without the common carotid artery compression test performed poorly in assessing anterior communicating artery patency, differing significantly from CTA.
Standalone CE-TCCS differed significantly from CTA (p < 0.001)
Consistency between standalone CE-TCCS and CTA was poor: Kappa = 0.126 (95% CI: 0.053–0.199, p = 0.013)
70.4% of patent ACoA cases were missed by CE-TCCS alone
The addition of the CCC test was therefore critical for functional assessment of ACoA patency
Results
The functional anterior communicating artery patency rate detected by CE-TCCS combined with the CCC test was 77.2% among evaluable patients.
Functional patency was assessed in 92 of the original 116 patients
24 patients were excluded from ACoA patency assessment due to unilateral absence of the ACA-A1 segment identified on CE-TCCS
Functional patency (77.2%) reflects hemodynamically active collateral flow through the ACoA, as opposed to purely anatomical patency on CTA
Results
CE-TCCS identified unilateral absence of the ACA-A1 segment in 24 of 116 patients, which precluded ACoA patency assessment in those individuals.
24 patients (approximately 20.7% of the cohort) were excluded from ACoA assessment due to unilateral ACA-A1 absence
Detection of ACA-A1 absence by CE-TCCS served as a prerequisite filter before applying the CCC test
This finding highlights the anatomical variability in the circle of Willis among patients with symptomatic carotid artery stenosis
What This Means
This research suggests that a specialized ultrasound technique, called contrast-enhanced transcranial color-coded sonography (CE-TCCS), combined with a temporary neck compression maneuver (common carotid artery compression, or CCC test), can reliably assess whether a critical brain blood vessel called the anterior communicating artery (ACoA) is functioning before patients undergo carotid endarterectomy surgery. The ACoA is part of the brain's backup circulatory network and knowing whether it is actively working helps surgeons understand how safely they can operate on blocked neck arteries. Many patients have skull bones too dense to allow standard ultrasound to image brain vessels clearly, making this assessment difficult without CT scanning with contrast dye (CTA).
The study enrolled 116 such difficult-to-image patients and found that adding a contrast agent to the ultrasound dramatically improved the ability to see brain vessels. When the CCC test was added — briefly pressing on the neck artery to redirect blood flow and reveal whether the ACoA compensates — the combined technique achieved 94.67% sensitivity and 100% specificity compared to CTA, with an overall accuracy of 95.65% and excellent agreement (Kappa = 0.868). By contrast, using CE-TCCS alone without the compression test was unreliable, missing 70.4% of cases where the ACoA was actually open and functioning.
This research suggests that combining ultrasound contrast agents with the compression maneuver could provide surgeons a practical, non-invasive bedside tool for preoperative planning in patients who are hard to image with standard ultrasound, potentially reducing reliance on CTA in this specific clinical context. The findings are relevant for centers performing carotid artery surgery, as understanding collateral blood flow through the ACoA is important for surgical decision-making and predicting how well patients will tolerate temporary interruption of blood flow during the procedure.
Liu Y, Zheng S, Gan Y, Wang S, He W, Zhang W. (2026). The role of contrast-enhanced transcranial color-coded real-time sonography combined with the common carotid artery compression test in preoperative evaluation of anterior communicating artery patency in patients with insufficient temporal bone windows.. Frontiers in neurology. https://doi.org/10.3389/fneur.2026.1806901