What’s New in Photon Counting CT?

May 27, 2026 · 9 articles · 11 research themes · covering May 20, 2026 – May 27, 2026

Overview

Across this week’s set of studies and reviews, a clear theme is the maturation of photon-counting CT (PCD/PCCT) from a hardware innovation into a quantitative, protocol-driven imaging platform. Multiple works focus on optimizing acquisition and reconstruction choices—such as spatial resolution, quantum iterative reconstruction, and single-scan virtual noncontrast workflows—to improve measurement reliability (e.g., inter-reader reproducibility of myocardial ECV) and to stabilize quantitative outputs (e.g., coronary stent lumen/strut metrics). Together, these studies emphasize that the benefits of photon-counting CT are realized not only through spectral capabilities, but also through careful parameter selection and reconstruction strategy.

A second dominant thread is dose and workflow optimization without sacrificing diagnostic performance. Phantom and protocol studies in pulmonary nodules, temporal bone imaging, and non-contrast head CT show that ultra-low-dose or dose-adjusted PCD-CT can maintain acceptable image quality and quantitative detectability/volumetry relative to energy-integrating CT benchmarks. This supports a practical transition pathway for emergency and follow-up contexts where radiation dose and robustness of quantitative measurements are both critical.

Finally, the cardiovascular literature highlights a convergence of advanced CT quantification with AI and functional surrogates. Reviews and clinical case reporting underscore multiparametric coronary CT angiography—combining stenosis, plaque biomarkers, and FFR-CT—while deep learning and spatial-resolution studies show how automated plaque/stenosis quantification can be tuned for reliability. In parallel, photon-counting CT’s spectral and metal-handling advantages are demonstrated for stent evaluation and viability-relevant tissue characterization, pointing toward more dependable, noninvasive coronary assessment in complex patients.

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Photon-counting CT (PCD/PCCT) hardware & reconstruction optimization

Effect of quantum iterative reconstruction on coronary stent assessment in ultra-high resolution photon-counting detector CT: a phantom study.

This phantom study evaluated the effect of quantum iterative reconstruction (QIR) on coronary stent assessment metrics—contrast-to-noise ratio (CNR), lumen diameter, and stent strut thickness—using ultra-high-resolution photon-counting detector CT (PCD-CT) at 120 and 140 kVp. In a 3D-printed coronary phantom with multiple stent types, QIR altered objective image quality measures, improving or stabilizing CNR and enabling more accurate lumen and strut thickness quantification compared with non-QIR reconstructions. These results support reconstruction-parameter optimization to improve quantitative stent evaluation with photon-counting CT in settings where measurement precision is critical.

Scheuer ST, Kusk MW, Sæderup H et al. · European radiology experimental · (2026) · View on PubMed ↗ · Free PDF ↗

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Quantitative cardiac CT: myocardial ECV and tissue characterization

Virtual Noncontrast Images Derived From Photon-Counting CT Enhance Inter-Reader Reproducibility of Myocardial ECV Measurement in Patients With Cardiac Devices.

This retrospective study evaluated whether a single-scan virtual noncontrast (VNC) method derived from photon-counting CT (PCCT) improves inter-reader reproducibility of left-ventricular extracellular volume fraction (ECV) measurements in 59 patients, including groups with atrial fibrillation and cardiac implantable electronic devices/prosthetic valves. The PCCT VNC approach reduced misregistration-related variability compared with the standard two-scan subtraction method, yielding enhanced inter-reader agreement for myocardial ECV. This supports more reliable, single-acquisition ECV quantification for risk stratification and myocardial characterization in patients where conventional CT ECV workflows are less reproducible due to rhythm/implant artifacts.

Yamakami Y, Hirasawa K, Hada H et al. · Journal of computer assisted tomography · (2026) · View on PubMed ↗

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AI-enabled multiparametric coronary risk assessment (AI-QCT, FFR-CT)

Advanced Quantitative CT for Coronary Artery Disease: Integrating Stenosis-, Plaque Quantification, and FFR-CT.

This review article examined advanced quantitative coronary CT angiography (CCTA) approaches that integrate stenosis assessment, plaque quantification, and FFR-CT to improve coronary artery disease (CAD) evaluation beyond conventional stenosis-only imaging. It highlights that AI-based quantitative CT (AI-QCT) can extract reproducible plaque biomarkers that enable more refined risk stratification for major adverse cardiovascular events (MACE) and potentially reduce inter-observer variability. Clinically, the synthesis supports a shift toward multiparametric, AI-enabled CCTA workflows combining anatomy and functional surrogates (FFR-CT) for better CAD prognostication.

Mihalcioiu S, Mengesha B, Abitbol C et al. · The British journal of radiology · (2026) · View on PubMed ↗

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Coronary stent imaging and metal artifact mitigation

Photon-Counting Computed Tomography for In-Stent Occlusion: Lumen Visualization and Myocardial Viability.

This JACC Case Reports report described a 58-year-old man with prior right coronary artery stenting who presented with crescendo chest pain and was evaluated for in-stent occlusion and myocardial viability. Ultra-high-resolution photon-counting CT (PCCT) demonstrated chronic total in-stent occlusion with robust collateralization, and spectral iodine mapping identified a nonviable transmural scar. The case illustrates how PCCT can noninvasively overcome metal blooming limitations of conventional CT to visualize stent lumen and provide viability-relevant tissue characterization in a single acquisition.

Nguyen KV, Nguyen VT, Nguyen NT et al. · JACC. Case reports · (2026) · View on PubMed ↗ · Free PDF ↗

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Deep learning–based automated coronary quantification

Deep Learning-Based Automated Coronary Plaque Quantification with Ultra-high Resolution Photon-Counting Detector CT at Different Spatial Resolutions.

This prospective single-center study assessed how different spatial resolutions (0.6 mm standard resolution, 0.4 mm high resolution, and 0.2 mm ultra-high resolution) affect image quality and deep learning–based automated quantification of coronary stenosis and plaque volumes in 70 patients undergoing ultra-high-resolution photon-counting detector CT (UHR-CCTA). The deep learning tool produced automated plaque/stenosis measurements across reconstructions while subjective image quality and quantitative outputs varied with spatial resolution. The work supports selecting spatial resolution settings that balance image quality and quantitative plaque assessment reliability for AI-driven coronary risk evaluation.

Liu Y, Li R, Zhang H et al. · Academic radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Temporal bone CT protocol optimization

Appropriate dose reduction using photon-counting detector CT for temporal bone imaging: phantom and clinical studies with helical acquisition.

This study combined phantom and clinical helical acquisition experiments to determine how much radiation dose can be reduced with photon-counting detector CT (PCD-CT) for temporal bone imaging while maintaining image quality equivalent to standard-dose energy-integrating detector CT (EID-CT). Using visual scoring at standard dose and detectability index (d’) measurements in a head phantom across dose levels, the authors identified a dose-reduction limit for PCD-CT that preserved detectability comparable to EID-CT. The findings are significant for implementing safer temporal bone CT protocols that reduce patient exposure without sacrificing diagnostic performance.

Takahashi Y, Higaki F, Nakamura Y et al. · Japanese journal of radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Non-contrast head CT protocol transition (PCD-CT vs EID-CT)

Photon Counting CT of the Head: Retrospective Analysis of Image Quality and Dose in Comparison to Energy Integrating Detector CT.

This retrospective comparative study evaluated non-contrast head CT (NCCT) image quality and dose using photon-counting detector CT (PCD-CT) at 120 and 140 kVp across varying radiation doses versus a modern energy-integrating detector CT (EID-CT) system. The results showed that PCD-CT performance depended on acquisition parameters and could achieve image-quality outcomes comparable to EID-CT while enabling dose adjustments. This provides practical evidence for optimizing emergency NCCT protocols when transitioning from EID-CT to photon-counting CT.

Schoenbeck D, Kroeger JR, Moenninghoff C et al. · Academic radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Pulmonary nodule detection and volumetry with photon-counting CT

Impact of Ultra-Low-Dose Imaging on Image Quality and Volumetric Accuracy of Different Subtypes of Pulmonary Nodules using Photon-Counting Detector CT: A Phantom Study.

This phantom study assessed how ultra-low-dose scanning on ultra-high-resolution photon-counting detector CT (UHR PCD-CT) affects detection rate, image quality, and volumetric accuracy across 15 pulmonary nodule models of different sizes and subtypes. Ultra-low-dose protocols maintained acceptable image quality and improved/ preserved volumetric measurement performance compared with higher-dose reference conditions, with quantitative changes in noise, signal-to-noise ratio, and contrast-to-noise ratio tracked across dose levels. The findings support dose-optimization strategies for photon-counting CT pulmonary nodule evaluation while preserving quantitative volumetry relevant to detection and follow-up.

Wang Y, Zhou Y, Lei L et al. · The British journal of radiology · (2026) · View on PubMed ↗

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Pediatric imaging trends and evidence gaps

Innovations in pediatric imaging: a scoping review of the past decade with case illustrations.

This scoping review summarized the last decade of pediatric imaging research (2015–2025) using MEDLINE searches and supplemented findings with illustrative cases from an institutional cohort. It mapped trends and evidence gaps across pediatric ultrasonography, X-ray, CT, and MRI, emphasizing how imaging is increasingly central to pediatric diagnostic work-ups and how reporting/quality considerations have evolved. The review is significant for guiding future pediatric imaging research and improving evidence-based selection and communication of imaging strategies in children.

Beer MJ, Schaal MC, Neubauer H · World journal of pediatrics : WJP · (2026) · View on PubMed ↗ · Free PDF ↗

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Generated automatically on May 27, 2026. Covers PubMed articles published May 20, 2026 – May 27, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.