What’s New in Photon Counting CT?

September 27, 2026 · 7 articles · 6 research themes · covering September 20, 2026 – September 27, 2026

Overview

Across these studies, photon-counting and spectral CT technologies are being pushed toward more quantitative, dose-efficient imaging. Several articles focus on how detector physics and acquisition settings translate into measurable performance gains—most notably PCCT’s improved dose efficiency while preserving image quality in complex, repeated 4D parathyroid imaging, and protocol optimization work in pediatric chest imaging showing that tin filtration and image-quality targets change dose/noise behavior.

A second dominant theme is standardizing quantitative biomarkers using energy-resolved reconstructions. Virtual monochromatic imaging parameter choices are shown to reduce variability and improve robustness of hepatic fat fraction estimation across body sizes, while a systematic review highlights the growing use of CT-derived myocardial extracellular volume as a diffuse fibrosis biomarker and positions PCCT’s spectral capabilities as a route to address limitations relative to CMR.

Finally, the digest also includes translational and mechanistic applications that extend beyond routine diagnostics: imaging cryoprotectant diffusion kinetics in tissue surrogates using multispectral photon-counting CT to support cryopreservation and tissue engineering, and using spectral photon-counting CT acquisition parameters to tune x-ray-induced fluorescence from functionalized gadolinium nanoparticles for multimodal theranostic strategies. Complementing these technology-focused advances, a clinical retrospective study evaluates when repeat myelography is likely to yield actionable findings after an initially nonlocalizing exam in suspected spontaneous intracranial hypotension.

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PCCT-Based Quantification of Hepatic Steatosis (Fat Fraction)

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

The study used 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 report that the MSCT approach can quantitatively map heterogeneous, spatiotemporal cryoprotectant transport within the phantom. This provides a non-invasive imaging framework to measure cryoprotectant diffusion kinetics 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 ↗

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 derived FF estimates via linear regression and identified VMI energy/settings that minimized relative root-mean-square error across body sizes. This is significant because it standardizes PCCT-based fat quantification, improving robustness of hepatic steatosis assessment across patients with different body habitus.

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

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Photon-Counting CT (PCCT) vs Conventional CT Performance and Dose Efficiency

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). The key finding is that PCCT improves dose efficiency and maintains or enhances image quality relative to EIDCT for the repeated noncontrast and multiphase contrast-enhanced acquisitions required in 4DCT. Clinically, this supports using PCCT to reduce radiation exposure while preserving diagnostic performance in anatomically complex neck imaging.

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

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Repeat Diagnostic Imaging Strategies in Suspected CSF Disorders (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 myelogram in 71 patients with suspected spontaneous intracranial hypotension, with an additional subgroup 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 findings are clinically important for guiding escalation of diagnostic workup for suspected CSF-venous fistula when the first myelogram is nonlocalizing.

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

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Photon-Counting CT for Cardiac Quantitative Biomarkers (Myocardial 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 current evidence on CT-derived myocardial extracellular volume (ECV), focusing on its clinical utility and the emerging role of photon-counting CT (PCCT) for ECV estimation. The review concludes that CT-derived myocardial ECV is increasingly studied as a quantitative biomarker of diffuse fibrosis, with cardiac magnetic resonance (CMR) remaining the reference standard, and highlights how PCCT may improve ECV measurement through spectral/energy-resolved capabilities. Scientifically, it clarifies where CT-ECV is validated and where PCCT-based methods could reduce limitations before broader clinical adoption.

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

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Optimization of Pediatric PCCT Protocols (Tin Filtration and Image Quality)

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 three anthropomorphic pediatric chest phantoms (1, 5, and 10 years), the authors compared clinical tin-filtered Sn100 kVp photon-counting CT (PCCT) against a non-tin-filtered 90 kVp protocol across image quality levels (IQLs). The key finding is that dose and noise behavior differ between the Sn100 kVp and 90 kVp protocols as IQL changes, characterizing how tin filtration and PCCT detector physics affect pediatric imaging performance. This is significant for optimizing pediatric chest PCCT protocols to achieve target image quality with minimized radiation exposure.

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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Spectral/Photon-Counting CT for Nanoparticle Activation and Fluorescence 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 surface-functionalized gadolinium fluoride (GdTbF3) nanoparticles (GdF3 nanoparticles doped with terbium) and how this depends on x-ray dose. The authors report that SPCCT settings can be optimized to modulate fluorescence emission, supporting improved multimodal imaging performance using nanoparticle activation. This is important for developing combined high-contrast imaging and theranostic strategies that leverage photon-counting detectors to tune nanoparticle-driven fluorescence.

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