What’s New in Photon Counting CT?

September 21, 2026 · 8 articles · 8 research themes · covering September 14, 2026 – September 21, 2026

Overview

Across this week’s studies, photon-counting CT (PCCT/PCD-CT) is shown to be moving from detector promise toward practical clinical utility—especially for quantitative imaging and post-procedural assessment. Multiple clinical cohorts demonstrate that PCCT can improve diagnostic confidence or enable clinically meaningful biomarkers: PCCT coronary angiography supports noninvasive detection of in-stent restenosis, time-resolved PCD-CT hemodynamic metrics improve identification of prosthetic valve dysfunction after TAVI, and PCCT-derived epicardial adipose tissue volume is associated with atrial fibrillation recurrence after ablation.

Methodologically, the work also emphasizes how to tune acquisition and reconstruction for reliable quantitative outcomes. Dose and physics studies indicate that ultra-low-dose PCCT can alter quantitative lung metrics and image quality in a metric- and kernel-dependent way, while spectral/virtual monoenergetic imaging reduces—but does not eliminate—dependence on tube voltage for CT values and contrast-to-noise ratio. Complementing these performance-focused papers, a head-and-neck review consolidates the rationale for PCCT adoption (resolution, noise/metal artifact reduction, spectral capabilities, and lower contrast/radiation burden), and an otosclerosis case series illustrates how PCCT can reduce missed diagnoses by better depicting stapes footplate fixation.

Finally, translational imaging is represented by spectral photon-counting CT work on Tb-doped GdTbF3 nanoparticles, where SPCCT dose/acquisition parameters modulate fluorescence emission. Together, these findings suggest a convergence: PCCT is not only improving visualization, but also enabling parameter-controlled, quantitative, and potentially multimodal imaging strategies that can be optimized for real-world clinical workflows.

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Nanoparticle activation & fluorescence imaging with spectral photon-counting CT

Optimizing x-ray based multimodal imaging: investigating dose dependency and modulation of fluorescence emission from GdF3nanoparticles doped with terbium using spectral photon counting CT.

This study investigated how spectral photon-counting CT (SPCCT) irradiation and acquisition parameters affect x-ray–induced activation and imaging performance of surface-functionalized GdTbF3 nanoparticles (GdTbF3NPs) doped with terbium (Tb). The key finding was that SPCCT dose/acquisition settings modulate fluorescence emission from the GdTbF3NPs, enabling optimization of imaging/activation protocols. This is significant because it supports translating Tb-doped GdF3-based multimodal (CT plus fluorescence) nanoparticle imaging toward in vivo use by defining practical SPCCT parameters for reliable signal generation.

Akl P, Gautheron A, Antonuccio MN et al. · Physics in medicine and biology · (2026) · View on PubMed ↗ · Free PDF ↗

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Cardiac imaging with photon-counting CT (coronary & stent assessment)

In vivo coronary stent evaluation using photon-counting computed tomography: diagnostic performance.

This retrospective single-center study evaluated photon-counting CT (PCCT) coronary angiography in 141 consecutive patients with coronary stents, comparing diagnostic performance for in-stent restenosis (ISR) ≥50% against invasive coronary angiography and comparing image quality versus energy-integrating detector (EID) CT. The key finding was that PCCT provided clinically useful diagnostic accuracy for detecting ISR ≥50% while maintaining or improving in-stent lumen image quality relative to EID-CT. This is significant because it supports PCCT as a noninvasive alternative for post-stent surveillance with potentially better contrast/noise characteristics for assessing ISR.

Lacaita PG, Bilgeri V, Spitaler P et al. · European radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Otolaryngology/otosclerosis imaging with PCCT

Photon-counting CT for preoperative assessment of stapes footplate fixation in otosclerosis.

This retrospective case series studied photon-counting CT (PCCT) findings in 18 patients with surgically confirmed otosclerosis to identify stapes footplate fixation and to quantify missed diagnoses on initial radiology reports. The key finding was that PCCT imaging features of stapes footplate involvement (e.g., increased thickness and/or hypoattenuation) correlated with intraoperative findings, and that initial reports sometimes failed to recognize these findings. This is significant because it suggests PCCT can improve preoperative detection of stapes fixation and reduce diagnostic misses in otosclerosis surgical planning.

Arora M, Seyedsaadat SM, Breen JT et al. · European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery · (2026) · View on PubMed ↗

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Dose reduction & ultra-low-dose photon-counting CT performance

Quantitative and qualitative lung parameters in photon-counting CT: comparison of ultra-low-dose with standard low-dose protocols.

This prospective study compared ultra-low-dose (ULD) versus standard low-dose (LD) photon-counting CT (PCCT) in 101 patients, assessing quantitative lung parameters (e.g., noise index, airway segmentation metrics, emphysema index, mean lung density, Percentile15) and qualitative image quality using automated quantitative CT (QCT) and two-reader scoring. The key finding was that ULD PCCT altered quantitative lung measurements and image quality compared with LD, with performance varying by lung/airway metric and reconstruction kernel (Br36u soft vs Bl64u lung). This is significant because it defines how far PCCT dose can be reduced while preserving clinically reliable quantification of airways and emphysema.

Kroschke J, Jungblut L, von Stackelberg O et al. · European radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Cardiac valve assessment & hemodynamics after TAVI using PCD-CT

Photon-counting detector CT for prediction of valve dysfunction after transcatheter aortic valve implantation: Comparison with echocardiography.

This retrospective single-center study evaluated time-resolved photon-counting detector (PCD)-CT–derived hemodynamic parameters after transcatheter aortic valve implantation (TAVI) in consecutive post-TAVI patients, comparing diagnostic accuracy for prosthetic valve dysfunction against echocardiography. The key finding was that PCD-CT–based functional assessment using measured prosthetic valve orifice area and derived hemodynamic metrics improved identification of valve dysfunction relative to echocardiography-based reference. This is significant because it supports PC D-CT as a noninvasive method that can integrate anatomic and hemodynamic information for post-TAVI evaluation.

Hyska S, Osoria-Velasquez J, Hagar MT et al. · Journal of cardiovascular computed tomography · (2026) · View on PubMed ↗ · Free PDF ↗

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Atrial fibrillation risk stratification with PCCT-derived biomarkers

Epicardial adipose tissue in paroxysmal and persistent atrial fibrillation ablation using photon counting CT and automated 3D atrial segmentation: The Prospective AFAT Study.

This prospective observational Prospective AFAT Study quantified epicardial adipose tissue (EAT) in 210 adults with first-time catheter ablation for paroxysmal versus persistent atrial fibrillation using photon-counting CT (PCCT) with semiautomated 3D biatrial segmentation, and tested associations with arrhythmia recurrence. The key finding was that volumetric EAT quantification from PCCT was associated with recurrence risk after ablation, with differences between paroxysmal and persistent AF cohorts. This is significant because it provides a precise imaging biomarker for AF recurrence that may help risk stratification and patient selection for ablation strategies.

Erhard N, Bahlke F, Prommersberger S et al. · Heart rhythm · (2026) · View on PubMed ↗ · Free PDF ↗

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Head & neck imaging applications of photon-counting CT

Photon-counting CT in head and neck radiology: bridging detector physics and clinical applications.

This article reviewed photon-counting CT (PCCT) in head and neck radiology, focusing on how detector physics translate into clinical advantages compared with energy-integrating detector CT (EID-CT). The key finding was that PCCT’s improved spatial resolution, reduced noise and metal artifacts, lower radiation exposure, reduced iodinated contrast dose, and spectral imaging capabilities collectively enhance visualization of small structures (e.g., vessels, ossicles, cartilage) and support better preoperative and postoperative assessment. This is significant because it consolidates the evidence base and practical implications for adopting PCCT in head and neck imaging workflows.

Martín-Noguerol T, Escartín J, López-Úbeda P et al. · European radiology · (2026) · View on PubMed ↗

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Photon-counting CT physics & spectral/quantitative optimization

Influence of X-ray Tube Voltage on Computed Tomography Values and Contrast-Noise Ratios in Virtual Monoenergetic Images in routine clinical Photon Counting Detector Computed Tomography: Does kV Still Matter?

This phantom study investigated whether tube voltage (kV) still affects computed tomography values and contrast-to-noise ratios in virtual monoenergetic images (VMIs) from routine clinical photon-counting detector CT (PCD-CT). The key finding was that VMI CT values show reduced dependence on kV compared with conventional polyenergetic CT, but kV can still influence contrast-to-noise ratio depending on tissue type, VMI keV, and phantom size. This is significant because it informs how to choose kV settings for quantitative spectral imaging with PCD-CT to optimize CNR while maintaining VMI-based comparability across scans.

Jeukens CRLPN, Pinckaers FME, Martens B et al. · Investigative radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Generated automatically on September 21, 2026. Covers PubMed articles published September 14, 2026 – September 21, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.