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Updated: Jul 16, 2026

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
Prognostic value of a novel artificial intelligence-based coronary CTA-derived ischemia algorithm among patients with
Sarah Bär1, Teemu Maaniitty2, Takeru Nabeta3
1Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland; Department of Cardiology, Bern University Hospital Inselspital, Bern, Switzerland.
Insights
An artificial intelligence algorithm (AI-QCTischemia) can predict cardiac ischemia in patients with obstructive coronary artery disease (CAD). The AI tool showed prognostic value in patients with normal downstream PET perfusion, but not in those with reduced perfusion.
Area of Science:
- Cardiology
- Medical Imaging
- Artificial Intelligence
Background:
- Coronary computed tomography angiography (CTA) is used to assess obstructive coronary artery disease (CAD).
- Positron emission tomography (PET) perfusion imaging can further evaluate myocardial ischemia in patients with obstructive CAD.
- A novel artificial-intelligence-guided quantitative computed tomography ischemia algorithm (AI-QCTischemia) aims to predict ischemia directly from coronary CTA.
Purpose of the Study:
- To evaluate the prognostic value of AI-QCTischemia in patients with obstructive CAD.
- To compare the prognostic performance of AI-QCTischemia in patients with normal versus abnormal downstream PET perfusion.
Main Methods:
- A retrospective cohort of patients with obstructive CAD on coronary CTA referred for 15O-H2O-PET perfusion imaging was analyzed.
- AI-QCTischemia was calculated by blinded analysts.
- The primary endpoint was a composite of death, myocardial infarction, or unstable angina pectoris, with a median follow-up of 6.2 years.
Main Results:
- AI-QCTischemia provided conclusive results for 86% of patients.
- In patients with normal PET perfusion, an abnormal AI-QCTischemia result was associated with a significantly higher risk of the primary endpoint (adjusted HR 2.47).
- This association was not observed in patients with abnormal PET perfusion (adjusted HR 1.09), with a significant interaction (p=0.039).
Conclusions:
- AI-QCTischemia demonstrated incremental prognostic value in patients with obstructive CAD and normal downstream PET perfusion.
- The algorithm did not show significant prognostic value in patients with reduced PET perfusion.
- AI-QCTischemia may aid in risk stratification for select patients with obstructive CAD.
Background:
Among patients with obstructive coronary artery disease (CAD) on coronary computed tomography angiography (CTA), downstream positron emission tomography (PET) perfusion imaging can be performed to assess the presence of myocardial ischemia. A novel artificial-intelligence-guided quantitative computed tomography ischemia algorithm (AI-QCTischemia) aims to predict ischemia directly from coronary CTA images. We aimed to study the prognostic value of AI-QCTischemia among patients with obstructive CAD on coronary CTA and normal or abnormal downstream PET perfusion.
Methods:
AI-QCTischemia was calculated by blinded analysts among patients from the retrospective coronary CTA cohort at Turku University Hospital, Finland, with obstructive CAD on initial visual reading (diameter stenosis ≥50%) being referred for downstream 15O-H2O-PET adenosine stress perfusion imaging. All coronary arteries with their side branches were assessed by AI-QCTischemia. Absolute stress myocardial blood flow ≤2.3 ml/g/min in ≥2 adjacent segments was considered abnormal. The primary endpoint was death, myocardial infarction, or unstable angina pectoris. The median follow-up was 6.2 [IQR 4.4-8.3] years.
Results:
662 of 768 (86%) patients had conclusive AI-QCTischemia result. In patients with normal 15O-H2O-PET perfusion, an abnormal AI-QCTischemia result (n = 147/331) vs. normal AI-QCTischemia result (n = 184/331) was associated with a significantly higher crude and adjusted rates of the primary endpoint (adjusted HR 2.47, 95% CI 1.17-5.21, p = 0.018). This did not pertain to patients with abnormal 15O-H2O-PET perfusion (abnormal AI-QCTischemia result (n = 269/331) vs. normal AI-QCTischemia result (n = 62/331); adjusted HR 1.09, 95% CI 0.58-2.02, p = 0.794) (p-interaction = 0.039).
Conclusion:
Among patients with obstructive CAD on coronary CTA referred for downstream 15O-H2O-PET perfusion imaging, AI-QCTischemia showed incremental prognostic value among patients with preserved perfusion by 15O-H2O-PET imaging, but not among those with reduced perfusion.
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