What’s New in Photon Counting CT?

September 28, 2026 · 7 articles · 8 research themes · covering September 21, 2026 – September 28, 2026

Overview

Across these studies, photon-counting and spectral CT are repeatedly positioned as tools for more quantitative, protocol-robust imaging—often with the promise of reducing radiation dose while preserving or improving diagnostic performance. Several works focus on optimizing acquisition parameters (energy binning, virtual monochromatic imaging settings, and spectral shaping) to improve measurement consistency, including hepatic fat fraction quantification across body sizes and diffusion/transport mapping in tissue-mimicking phantoms. Complementing this, a clinical comparison of photon-counting CT versus conventional energy-integrating CT in 4D parathyroid imaging highlights dose reduction without sacrificing image quality metrics.

A second dominant theme is standardization and tissue characterization. The systematic review on CT-derived myocardial extracellular volume (ECV) synthesizes evidence for clinical feasibility while clarifying where cardiac MRI remains the reference standard, and how photon-counting CT may improve quantitative reliability for diffuse myocardial disease. In parallel, phantom-based pediatric chest CT work demonstrates that detector spectral shaping (including tin filtration) changes dose–noise behavior across image quality levels, enabling more informed protocol selection for low-dose pediatric imaging.

Finally, the digest spans translational and clinical decision-making endpoints. A nanoparticle theranostics study links spectral photon-counting CT acquisition parameters to x-ray-induced fluorescence output from activatable terbium-doped gadolinium fluoride nanoparticles, suggesting detector-driven optimization for combined imaging/therapy strategies. On the clinical side, a retrospective analysis evaluates when repeat myelography is likely to be beneficial after an initially nonlocalizing study in suspected spontaneous intracranial hypotension, providing evidence to guide follow-up imaging for suspected CSF-venous fistula localization.

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Photon-Counting CT (PCCT) Dose & Image Quality Comparisons

Quantitative Evaluation of Image Quality Improvement and Reduced Radiation Output with Photon-Counting CT in 4D Parathyroid Imaging.

This work compared photon-counting CT (PCCT) versus conventional energy-integrating detector CT (EIDCT) for 4D parathyroid imaging in terms of radiation output (CTDIvol and DLP) and image quality (SNR and contrast-to-noise ratio) across repeated noncontrast and multiphase contrast-enhanced acquisitions. The key finding was that PCCT can reduce radiation dose while maintaining or improving quantitative image quality metrics for anatomically complex neck imaging. Clinically, this could lower patient exposure in 4DCT workflows while preserving diagnostic performance for parathyroid localization.

Arizono E, Buch K, Kelly HR et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗ · Free PDF ↗

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PCCT Spectral/Multienergy Imaging for Tissue/Phantom Transport Studies

Photon counting multi-spectral x-ray computed tomography of multi-component cryoprotectant diffusion into tissue surrogate.

The study investigated photon-counting multi-spectral x-ray computed tomography (MSCT) with an empirical photon-energy bin selection algorithm to quantify how a ternary cryoprotectant mixture of dimethyl sulfoxide (DMSO), glycerol, and water diffuses into a hydrogel tissue surrogate mimicking human muscle. The authors found that MSCT with optimized energy binning could quantitatively map heterogeneous, spatiotemporal cryoprotectant transport within the phantom. This supports non-invasive, quantitative monitoring of cryoprotectant diffusion relevant to improving cryopreservation and tissue-engineering protocols.

Ali AM, Parker JT, Consiglio AN et al. · Physics in medicine and biology · (2026) · View on PubMed ↗ · Free PDF ↗

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PCCT Protocol Optimization for Pediatric/Low-Dose Imaging

Pediatric Chest Photon-counting CT: Dose and Noise Behavior of Clinical Sn100 kVp and 90 kVp Protocols across Image Quality Levels - a Phantom Study.

In a phantom study using anthropomorphic pediatric chest phantoms (1, 5, and 10 years), the authors compared clinical tin-filtered Sn100 kVp ultra-high-resolution (UHR) photon-counting CT (PCCT) protocols with a non-tin-filtered 90 kVp standard-resolution protocol across image quality levels (IQLs). The key finding was that dose and noise behavior differed by protocol and IQL, characterizing how tin filtration and PCCT spectral shaping affect pediatric imaging performance. This supports protocol optimization to achieve better image quality at lower radiation dose in pediatric chest CT.

Klüner LV, Zensen S, Peuster H et al. · RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin · (2026) · View on PubMed ↗

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Photon-Counting CT for Quantitative Body Composition (Hepatic Steatosis)

Uniform quantification of hepatic fat fraction across body sizes using photon-counting CT.

The study evaluated photon-counting CT (PCCT) virtual monochromatic imaging (VMI) settings to enable uniform hepatic fat fraction (FF) quantification across medium and large body sizes using anthropomorphic liver phantoms with six non-iodinated fat lesions of known FF (5%–40%). Using PCCT (NAEOTOM Alpha) at 120 and 140 kV and measuring CT numbers on VMIs from 40–190 keV, the authors identified VMI acquisition settings that minimized relative root-mean-square error between ground-truth FF and HU-derived estimates. This provides a practical, body-size-robust PCCT approach for more consistent quantification of hepatic steatosis.

Li X, Kallman C, Zhang D et al. · European journal of radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Photon-Counting CT for Quantitative Cardiac Tissue Characterization (ECV)

CT-derived myocardial extracellular volume: current evidence, clinical utility, and the emerging role of photon-counting CT-a systematic review.

This PRISMA-compliant systematic review synthesized evidence on CT-derived myocardial extracellular volume (ECV), focusing on its clinical utility and how photon-counting CT (PCCT) may expand performance and standardization. The review concluded that CT-derived ECV is increasingly feasible for assessing diffuse myocardial interstitial expansion/fibrosis, with cardiac magnetic resonance (CMR) remaining the reference standard, and highlighted emerging PCCT-specific opportunities and limitations. Scientifically, it clarifies where CT-ECV is ready for routine use and where PCCT could improve quantitative reliability for diffuse cardiac disease assessment.

D’Argenzio J, Stucchi F, Tambè V et al. · European radiology experimental · (2026) · View on PubMed ↗ · Free PDF ↗

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Clinical Decision-Making in Intracranial Hypotension Imaging (Myelography)

Diagnostic Yield of Repeat Myelography After an Initial Negative Study in Patients With Suspected Spontaneous Intracranial Hypotension.

This retrospective single-center study assessed the diagnostic yield of repeat myelography after an initially negative or nonlocalizing myelogram in 71 patients with suspected spontaneous intracranial hypotension, with additional analysis of 13 patients whose earlier suspicious target remained unresolved after treatment. Repeat examinations were classified as definite, suspicious, or negative, and the study identified clinical/imaging features associated with positivity to determine when repeating myelography is likely to be beneficial. The results inform evidence-based decision-making for follow-up spinal imaging in patients in whom a first myelogram does not localize a suspected CSF-venous fistula.

Callen AL, Jenkins K, Bhaumik D et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗

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Spectral Photon-Counting CT for Nanoparticle Fluorescence/Activatable Theranostics

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) acquisition parameters influence x-ray-induced fluorescence emission from terbium-doped gadolinium fluoride nanoparticles (GdTbF3 nanoparticles) and how these effects depend on dose and fluorescence modulation. The authors reported that SPCCT settings can be optimized to enhance activation and imaging of the functionalized GdF3:Tb nanoparticles, linking detector-based spectral acquisition to nanoparticle fluorescence output. This is significant for developing combined imaging/theranostic strategies that leverage photon-counting CT to improve contrast from activatable nanoparticle agents.

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

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Generated automatically on September 28, 2026. Covers PubMed articles published September 21, 2026 – September 28, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.