Cleerly AI-QCT Demonstrates High Agreement with Invasive IVUS in INVICTUS Registry

Multicenter INVICTUS Registry Demonstrates Strong Correlation Between Noninvasive AI-QCT and Invasive IVUS for Coronary Plaque Quantification

DENVER--(BUSINESS WIRE)--Cleerly, a leader in AI-based cardiovascular imaging analysis, presented findings from its multicenter INVICTUS registry at the recent European Congress of Radiology (ECR 2026) in Vienna, Austria. The presentation titled, “Artificial Intelligence-Based CCTA Quantification of Atherosclerosis Burden: Comparison With IVUS in the INVICTUS Registry” was presented by Rine Nakanishi, MD, PhD, during the Clinical Trials in Radiology: Spotlight Session on March 5, 2026. The analysis has also been simultaneously published in European Radiology.

INVICTUS, a multicenter registry of two cohorts of patients prospectively and retrospectively enrolled across 17 centers in Japan, aimed to evaluate the quantification and characterization of atherosclerosis by artificial intelligence-enabled quantitative computed tomography (AI-QCT) against “gold-standard” invasive imaging techniques such as intravascular ultrasound (IVUS), near-infrared spectroscopy IVUS (NIRS-IVUS), and optical coherence tomography (OCT).

IVUS is widely used during invasive coronary procedures to assess plaque burden and guide intervention. The authors investigated the diagnostic utility of AI-QCT quantification of coronary atherosclerosis across the whole spectrum of atheroma burden, including diseased and non-diseased continuous vascular segments.

Key Findings

AI-QCT demonstrated strong correlations compared to invasive "gold-standard" imaging IVUS, showing no significant difference in measuring arterial plaque across the whole coronary segment. AI-QCT showed strong correlation with IVUS (mean difference −0.09%), with 94.4% of measurements falling within the limits of agreement. Strong associations were seen between AI-QCT and IVUS in quantifying external elastic membrane volume (EEM) (r=0.899), lumen volume (r=0.943), plaque volume (r=0.833), length-normalized PAV (r=0.851), and calcium index (r=0.960). AI-QCT also demonstrated 99.1% agreement in classifying the predominant plaque type at the minimum lumen area. Strong correlations were also seen in segments with non-calcified plaque (NCP) and low-attenuation (LAP) for vessel, lumen, and plaque volumes.

Clinical and Strategic Implications

Unlike physiology-based imaging approaches that focus primarily on ischemia assessment, AI-QCT provides a comprehensive analysis of both total plaque burden and plaque composition using standard coronary computed tomography angiography (CCTA). These findings support the use of noninvasive plaque quantification with standard CCTA for comprehensive coronary plaque assessment.

"Every time we reach a scientific milestone that makes accurate plaque characterization more accessible and less invasive, we get closer to our goal of eliminating heart attacks. IVUS has long been the gold standard in invasive plaque imaging, and the findings from INVICTUS represent an important advance in establishing the clinical validity of noninvasive plaque quantification. The strong correlations across multiple metrics support AI-QCT as a reliable tool for comprehensive coronary plaque assessment,” said James K. Min, founder and CEO of Cleerly.

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About Cleerly

Cleerly is the company on a mission to eliminate heart attacks by creating a new standard of care for heart disease. Through its FDA-cleared solutions driven by artificial intelligence, Cleerly supports comprehensive phenotyping of coronary artery disease, as determined from advanced noninvasive CT imaging. Cleerly’s approach is grounded in science, based on millions of images from over 40,000 patients. Led by a world-class clinical and technical team, Cleerly enhances health literacy for each and every stakeholder in the coronary care pathway. For more information, please visit: cleerlyhealth.com.