What’s New in Photon Counting CT?

August 31, 2026 · 9 articles · 11 research themes · covering August 24, 2026 – August 31, 2026

Overview

This week’s set of studies and reviews converges on a central message: photon-counting detector CT (PCCT/PCD-CT) is moving from “better images” toward measurable, protocol-driven improvements in quantitative imaging. Multiple papers emphasize the technical levers that make this possible—spectral performance and material decomposition (including the role of x-ray pre-filtration), as well as how dose, spatial resolution, and reconstruction choices affect quantitative outputs such as trabecular microstructure metrics. Together, these works frame PCCT as a platform whose clinical value depends on optimizing acquisition and reconstruction to preserve quantitative accuracy at clinically relevant radiation doses.

Clinically, the dominant theme is improved diagnostic confidence and/or biomarker extraction in cardiopulmonary and vascular imaging. Reviews and comparative analyses highlight PCCT’s advantages for coronary assessment (reducing calcium blooming and stent-related artifacts), and a systematic review/meta-analysis evaluates whether PCCT can maintain diagnostic performance in CT pulmonary angiography while reducing dose and iodine load. Complementing this, a feasibility study extends PCCT into stress myocardial perfusion imaging after arterial switch operations, suggesting a potential role for PCCT-based iodine mapping in detecting late coronary abnormalities.

Beyond cardiopulmonary imaging, PCCT is also being used for more specialized anatomical phenotyping and structural biomarker work: atrial fibrillation patients show quantifiable interatrial septum and sinoatrial node/vascular structural markers; neurotology studies demonstrate direct measurement of the vestibular aqueduct trajectory; and a cerebrovascular CTA comparison tests whether higher spatial resolution improves classification of arterial outpouchings. Finally, a translational neonatal study uses photon-counting CT to assess supraglottic airway device positioning relative to perilaryngeal landmarks, underscoring PCCT’s emerging role in device evaluation and patient-specific anatomical guidance.

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Photon-Counting CT (PCCT) System Physics & Spectral/Material Decomposition

Material-dependent effects of x-ray pre-filtration on material decomposition in photon-counting CT.

This phantom study characterized how x-ray pre-filtration affects material decomposition (MD) performance in photon-counting CT (PCCT) across different filter materials and thicknesses using contrast agents spanning low-Z (iodine, barium) and high-Z (tantalum). Single-contrast phantoms (iodine, barium, or tantalum) and a dual-contrast iodine+tantalum phantom were scanned on a CdZnTe PCCT system under conditions including no pre-filter, 0.375 mm brass, and multiple copper/tin filtration settings, and MD basis-map performance was quantified. The results are important for selecting pre-filtration strategies that improve spectral separation and quantitative accuracy of material decomposition in PCCT.

Aubrey JD, Perkinson EP, Wang G et al. · Physics in medicine and biology · (2026) · View on PubMed ↗

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Coronary Artery Disease Imaging (CAD) with PCCT

Diagnostic performance and clinical impact of photon-counting detector computed tomography in coronary artery disease.

This article reviewed evidence on photon-counting detector CT (PCD-CT) for diagnosing coronary artery disease (CAD), focusing on how the technique addresses limitations of conventional coronary CT angiography such as calcium blooming, stent artifacts, and spatial-resolution constraints. The review reports that PCD-CT provides superior spatial resolution, improved contrast-to-noise ratio, and reduced blooming artifacts compared with energy-integrating detector CT (EID-CT). Scientifically and clinically, these advantages may translate into more accurate coronary assessment and potentially greater impact on patient management in CAD imaging.

Parikh R, Shin D, Ali ZA et al. · Current opinion in cardiology · (2026) · View on PubMed ↗

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CT Pulmonary Angiography (CTPA) with PCCT

Photon-counting detector CT for CT pulmonary angiography: a systematic review and meta-analysis.

This systematic review and meta-analysis compared photon-counting detector CT (PCCT) with energy-integrating detector CT (EID-CT) for CT pulmonary angiography (CTPA), focusing on radiation dose, contrast media utilization, image quality, and diagnostic performance. Across 12 studies (950 patients), the meta-analysis evaluated CTDIvol, total iodine load (TIL), SNR, and CNR using random-effects models, with sensitivity analyses including Hartung-Knapp adjustment. The results are important for determining whether PCCT can reduce dose/iodine while maintaining or improving diagnostic image quality for CTPA.

Kato S, Azuma M, Horita N et al. · European radiology · (2026) · View on PubMed ↗

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Cardiac Perfusion & Ischemia Imaging (Stress CT-MPI) with PCCT

Stress CT myocardial perfusion imaging after arterial switch operation for transposition of the great arteries.

This study evaluated feasibility and diagnostic performance of stress CT myocardial perfusion imaging (CT-MPI) in adults after arterial switch operation for transposition of the great arteries (ASO-TGA), using regadenoson stress. Patients underwent either dynamic energy-integrating detector CT (EID-CT) with quantitative myocardial blood-flow mapping or static photon-counting detector CT (PCCT) with qualitative and semiquantitative iodine-map assessment, and the abstract indicates comparison against stress cardiac magnetic resonance (C-MR) as the reference. Clinically, this supports the potential role of PCCT-based stress CT-MPI for detecting late coronary abnormalities after ASO-TGA.

Gkizas C, Longere B, Domanski O et al. · European heart journal. Imaging methods and practice · (2026) · View on PubMed ↗ · Free PDF ↗

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Atrial Fibrillation (AF) Structural Biomarkers via PCCT

Quantification of Atrial Fibrillation-Related Imaging Markers Using Spectral Photon-Counting Computed Tomography.

This study used spectral photon-counting computed tomography (PCCT) to quantify atrial fibrillation (AF)-related structural imaging markers in 65 AF patients versus 65 controls in sinus rhythm, focusing on the interatrial septum (IAS) along the anterior internodal bundle and the sinoatrial (SA) node and its vascular supply. Key findings (as reported in the abstract) indicate PCCT can quantify IAS fibrosis (scored 1–4) and measure IAS/SA-node density and SA-artery anatomy/length to differentiate AF patients from controls. Clinically, these quantitative PCCT biomarkers could improve noninvasive identification of conduction-system structural alterations associated with AF.

Bilgeri V, Spitaler P, Kindl B et al. · Heart rhythm · (2026) · View on PubMed ↗ · Free PDF ↗

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Cerebrovascular CTA Lesion Characterization (Aneurysm/Infundibulum) with PCD-CTA

Detection and Characterization of Infundibula and Aneurysms: A Clinical Report-Based Comparison of PCD- and EID-CTA.

This clinical report-based retrospective comparison evaluated how photon-counting detector CT angiography (PCD-CTA) versus energy-integrating detector CTA (EID-CTA) affects detection and characterization of arterial outpouchings in adults with paired head/neck CTA studies. Paired reports were compared for concordance in lesion classification (aneurysm vs infundibulum vs uncertain) under inclusion criteria such as paired scans within 2 years and EID-CTA slice thickness ≤0.6 mm, with PCD-CTA performed at 120 kV and 120×0.2 mm collimation. The findings are significant for understanding whether PCD-CTA’s higher spatial resolution improves radiologist confidence and accuracy in clinically reported cerebrovascular lesion characterization.

Jacobson Z, El Sadaney AO, Yu L et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Neurotology & Inner Ear Morphometry with PCCT

The angular trajectory of the vestibular aqueduct: evaluation using photon-counting CT.

This retrospective study used photon-counting CT (PCCT) temporal bone scans from 64 patients (128 ears) to directly visualize the proximal vestibular aqueduct and measure the angular trajectory of the vestibular aqueduct (ATVA). Two independent readers measured ATVA directly on PCCT and compared it with additional vestibular aqueduct morphometric parameters, with mean ATVA reported around 106.9° ± 11.7°. The ability to measure ATVA without reliance on conventional CT resolution-limited proxies could improve patient-specific radiographic phenotyping relevant to developmental endotypes of Menière’s disease.

Van den Kerkhof F, Boomgaert L, Cockmartin L et al. · Insights into imaging · (2026) · View on PubMed ↗ · Free PDF ↗

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Neonatal Airway Imaging & Device Placement Assessment

Computed tomography of three smaller-sized supraglottic airway device prototypes in stillborn low-birth-weight neonates.

The study evaluated three smaller-sized supraglottic airway device prototypes—including the smallest commercial i-gel® size 1.0 and Neo i-gel® prototype sizes 0.65, 0.75, and 0.85—in stillborn low-birth-weight neonates weighing >500 g using photon-counting CT. Photon-counting CT was used to assess anatomical positioning relative to perilaryngeal landmarks and effects on adjacent structures, demonstrating feasibility of imaging-based placement assessment for these neonatal airway devices. This supports development and optimization of neonatal resuscitation/surfactant delivery airway options where appropriately sized devices are currently limited.

Dempsey T, Brismar TB, Svensson-Marcial A et al. · British journal of anaesthesia · (2026) · View on PubMed ↗ · Free PDF ↗

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Bone Microstructure & Trabecular Quantification with PCCT

Assessment of trabecular microstructure using photon-counting CT: Influence of dose, spatial resolution and reconstruction algorithms.

The study assessed trabecular microstructure in excised human vertebral bodies using photon-counting CT (PCCT), testing how radiation dose, spatial resolution, and reconstruction algorithms affect quantitative metrics including bone mineral density (BMD), bone volume fraction (BV/TV), and trabecular separation (Tb.Sp). Using a clinical PCCT scanner (Naeotom Alpha, Siemens Healthineers) with scans at 20 mGy CTDIvol and lower doses (6–15 mGy) in a thorax phantom, and comparing filtered back projection (FBP) versus iterative reconstruction (QIR3), the authors evaluated algorithm- and dose-dependent performance of trabecular measurements. This is significant for optimizing PCCT protocols to enable reliable quantitative central-skeleton microstructural assessment at clinically relevant radiation doses.

Peña JA, Thomsen F, Damm T et al. · Bone · (2026) · View on PubMed ↗

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Generated automatically on August 31, 2026. Covers PubMed articles published August 24, 2026 – August 31, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.