Photon-counting CT (PCCT) performs with more accuracy than traditional CT imaging when it comes to identifying obstructive coronary stenosis, according to research presented at the Society of Cardiovascular Computed Tomography (SCCT) meeting being held in Washington, DC.
A group led by Melinda Boussoussou, MD, of Semmelweis University Heart and Vascular Center in Budapest, Hungary, reported that PCCT performed better than invasive coronary angiography (ICA) for diagnosing coronary artery disease (CAD), characterized by stenosis of 50% or more or 70% or more in a per-vessel analysis and using both standard and ultra-high resolution reconstructions.
Boussoussou and colleagues conducted a study that assessed the diagnostic efficacy of PCCT for this indication, using ICA as a reference. The study included 260 coronary vessels (left main, left anterior descending artery, left circumflex artery, and right coronary artery) imaged in patients who were experiencing stable chest pain and exhibiting stenosis of 50% or more on PCCT imaging and who later underwent an ICA procedure and the team calculated per-vessel sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of PCCT for detecting stenosis of 50% or 70% or more.
The team reported the following regarding PCCT's performance for detecting stenosis of 50% or more:
| PCCT's performance for detecting stenosis of 50% or 70% or more | ||
|---|---|---|
| Measure | 50% or more stenosis | 70% or more stenosis |
| Sensitivity | 100% | 95% |
| Specificity | 88% | 95% |
| Positive predictive value (PPV) | 81% | 89% |
| Negative predictive value (NPV) | 100% | 98% |
| Diagnostic accuracy | 92% | 95% |
PCCT's superior spatial resolution and use of spectral data make it effective for this indication, the team explained.
"Photon counting coronary CT (PCCT) angiography represents a groundbreaking approach to evaluating coronary stenosis," the group concluded.
![Axial images from unenhanced calcium score cardiac CT (left) and curved planar reformation images from CT angiography (right) show that higher long-term exposure to air pollution is associated with greater coronary artery calcium and more obstructive coronary artery disease (CAD). Top row: Images in a 68-year-old male patient with higher 10-year mean ambient air pollution exposure (7.9 μg/m3 for particulate matter measuring ≤2.5 μm in diameter [PM2.5] and 17.4 parts per billion [ppb] for NO2) with extensive CAD (coronary artery calcium score [CACS] >1,000 and obstructive CAD [≥70% diameter stenosis]). Bottom row: Images in a 57-year-old female patient with lower 10-year mean ambient air pollution exposure (6.3 μg/m3 for PM2.5 and 4.6 ppb for NO2) with no CAD (CACS = 0 and no obstructive stenosis).](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/06/hanneman.r6SMLzkezo.png?auto=format%2Ccompress&fit=crop&h=100&q=70&w=100)
![Axial images from unenhanced calcium score cardiac CT (left) and curved planar reformation images from CT angiography (right) show that higher long-term exposure to air pollution is associated with greater coronary artery calcium and more obstructive coronary artery disease (CAD). Top row: Images in a 68-year-old male patient with higher 10-year mean ambient air pollution exposure (7.9 μg/m3 for particulate matter measuring ≤2.5 μm in diameter [PM2.5] and 17.4 parts per billion [ppb] for NO2) with extensive CAD (coronary artery calcium score [CACS] >1,000 and obstructive CAD [≥70% diameter stenosis]). Bottom row: Images in a 57-year-old female patient with lower 10-year mean ambient air pollution exposure (6.3 μg/m3 for PM2.5 and 4.6 ppb for NO2) with no CAD (CACS = 0 and no obstructive stenosis).](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/06/hanneman.r6SMLzkezo.png?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
