What’s New in Photon Counting CT?

October 05, 2026 · 25 articles · 15 research themes · covering September 28, 2026 – October 05, 2026

Overview

Across this week’s set of studies and reviews, a dominant theme is that photon-counting CT (PCD/PCCT) is moving from “better detector physics” toward actionable clinical workflows—especially by improving dose efficiency and tailoring reconstruction/spectral processing to the diagnostic task. Multiple phantom and patient studies show that small changes in positioning, kernel selection, slice thickness, and virtual monoenergetic energy can measurably shift image noise, contrast, detectability, and even downstream quantitative interpretation (e.g., myeloma marrow thresholds, trauma vascular visibility, and post-TACE lesion conspicuity). Together, these results emphasize that PCCT performance is not just a hardware feature; it is a protocol-and-reconstruction problem that can be optimized for specific organs and clinical questions.

A second major thread is the expansion of CT beyond anatomy into risk stratification and quantitative biomarkers—most clearly in cardiac imaging. Reviews on coronary CT angiography (CCTA) highlight that prognosis and management planning increasingly depend on overall atherosclerotic burden and high-risk plaque features rather than stenosis severity alone, and that CT-derived physiology (including CT-FFR concepts) and AI-based quantitative measurements may reduce interobserver variability. Complementing this, opportunistic CAC detection on non-cardiac thoracic CT and case-based demonstrations of photon-counting coronary CT illustrate how spectral/PCCT capabilities could strengthen triage and diagnostic confidence in real-world pathways.

Finally, the digest shows broadening clinical translation of PCD/PCCT into oncology, neurovascular, musculoskeletal, and pediatric/perinatal domains. Spectral reconstructions and optimized parameters are being tested for peritoneal metastasis detection, HCC treatment-response assessment after TACE, and liver steatosis quantification via surrogate non-contrast imaging. In parallel, PCD-CT is being evaluated for neurovascular aneurysm measurement reproducibility, implant integration/osteolysis monitoring, metal artifact reduction in spine hardware, and lower-dose myelography for CSF-venous fistulas. Pediatric and neonatal studies further underscore the technology’s potential to reduce radiation while enabling precise dynamic or device-position assessments where conventional imaging constraints are especially challenging.

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Photon-Counting CT (PCD/PCCT) Dose & Image Quality Optimization

Photon-counting detector computed tomography (PCD-CT) in multiple myeloma: a systematic review and trial sequential meta-analysis on image quality and radiation dose.

This systematic review and trial sequential meta-analysis compared photon-counting detector CT (PCD-CT) versus energy-integrating detector CT (EID-CT) for image quality (sharpness) and radiation dose in patients with multiple myeloma (MM) bone lesions across 5 included studies (n=170). Overall, the analysis synthesized evidence on how PCD-CT affects CTDIvol and image sharpness relative to EID-CT, with methodological quality assessed using ROBINS-I and certainty graded with GRADE. Clinically, the work informs whether PCD-CT can improve diagnostic performance while reducing dose in MM patients undergoing CT for bone lesion assessment.

Ohannesian VA, Taneja BC, do Amaral E Castro A et al. · Skeletal radiology · (2026) · View on PubMed ↗

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

This study quantitatively evaluated image quality improvement and reduced radiation output with photon-counting CT in 4D parathyroid imaging, comparing photon-counting CT (PCCT) with energy-integrating detector CT (EIDCT). The key finding was that PCCT can improve dose efficiency and image quality, assessed using CTDIvol and DLP alongside signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Scientifically and clinically, this supports using PCCT to mitigate the higher radiation burden inherent to multiphase 4DCT protocols for parathyroid localization.

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

Impact of Vertical Off-centering on Radiation Dose and Image Noise in Photon-counting Computed Tomography: A Phantom Study.

This phantom study evaluated how vertical off-centering affects radiation dose and image noise in photon-counting CT (PCCT) across adult and pediatric body sizes using three anthropomorphic phantoms (adult male, 10-year-old, and 5-year-old) scanned at multiple vertical offsets. Vertical off-centering changed both dose and image noise, with the magnitude of the effect varying by phantom size. These findings support more accurate patient positioning and protocol optimization for PCCT to improve dose efficiency and image quality, especially in pediatric-sized patients.

Klüner LV, Haubold J, Peuster H et al. · Investigative radiology · (2026) · 2 citations · View on PubMed ↗

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Reconstruction Parameters, Virtual Monoenergetic Images & Spectral Processing

Impact of virtual monoenergetic images on the assessability of lower extremity arteries in (Poly-) trauma photon-counting detector CT.

This study investigated how virtual monoenergetic images (VME) derived from photon-counting detector CT (PCD-CT) affect assessability of lower extremity arteries in (poly-)trauma patients undergoing extended leg scanning with a double-bolus contrast protocol. The key finding was that VME reconstructions can achieve sufficient vascular contrast (defined as >200 Hounsfield Units) and that the choice of VME energy level influences vascular visibility. Clinically, this helps optimize post-processing parameters to improve detection of vascular pathology in trauma CT workflows.

Dillinger D, Bauer C, Kaatsch HL et al. · Emergency radiology · (2026) · View on PubMed ↗ · Free PDF ↗

Energy-resolved attenuation behaviour on dual-source photon-counting CT: Implications for quantitative assessment of femoral bone marrow in multiple myeloma.

This retrospective single-center study assessed energy-resolved attenuation behavior of femoral bone marrow on dual-source photon-counting CT in 103 patients with multiple myeloma, reconstructing virtual monoenergetic images at 40–190 keV to evaluate how marrow attenuation varies with photon energy. The key finding was that bone marrow attenuation is energy-dependent, which has direct implications for threshold-based quantitative differentiation between normal marrow and myeloma infiltration. Scientifically and clinically, it indicates that quantitative CT criteria for myeloma assessment must account for the selected VMI energy to avoid misclassification.

Heidemeier A, Scheiner F, Huflage H et al. · European journal of radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Clinical Risk Stratification & Quantitative Cardiac CT (CCTA/FFR-CT/CAC)

Photon-counting CT of midventricular takotsubo cardiomyopathy.

This Radiology Case Reports article describes a 63-year-old woman with acute chest pain and elevated troponin I after emotional stress, ultimately diagnosed with midventricular takotsubo cardiomyopathy, using photon-counting detector coronary CT angiography (PCD-CCTA). The key finding was that PCD-CCTA provided a comprehensive “one-stop-shop” evaluation by excluding obstructive coronary artery disease and using multiphase cine reconstructions to characterize the midventricular wall-motion abnormality pattern with basal and apical sparing. This highlights the potential of photon-counting coronary CT to improve diagnostic confidence and triage in atypical stress cardiomyopathy presentations.

Chikh Bakri I, Euler A · Radiology case reports · (2026) · View on PubMed ↗ · Free PDF ↗

Advanced quantitative CT for coronary artery disease: integrating stenosis quantification, plaque quantification, and fractional flow reserve-CT.

This review studied advanced quantitative CT approaches for coronary artery disease, focusing on integrating stenosis quantification, plaque quantification, and fractional flow reserve derived from CT (FFR-CT) within cardiac CT angiography workflows. The key finding is that AI-based quantitative CT can provide more reproducible plaque biomarker and stenosis measurements than conventional visual assessment, enabling more refined risk stratification for major adverse cardiovascular events. Scientifically and clinically, the review positions quantitative and physiology-informed CT (including FFR-CT) as a pathway to reduce interobserver variability and improve patient selection for downstream management.

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

Coronary artery calcium score-emerging role for opportunistic screening on thoracic CT and novel applications.

This review studied the emerging role of coronary artery calcium (CAC) scoring using opportunistic detection on non-cardiac thoracic CT (including lung cancer screening CT and attenuation-correction CT). The key finding is that identifying CAC on existing thoracic CT scans can improve cardiovascular risk assessment and potentially guide preventive therapies, despite the lack of randomized trials demonstrating clinical outcome benefit. Scientifically, it highlights a growing opportunity for AI/ML-enabled CAC detection and risk stratification within routine imaging workflows.

Patel R, Williams MC · The British journal of radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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High-Risk Plaque & Coronary Imaging Beyond Stenosis

Diagnostic and prognostic value of coronary computed tomography angiography and high-risk plaque assessment in acute coronary syndrome.

This review article evaluated the diagnostic and prognostic value of coronary computed tomography angiography (CCTA) and high-risk plaque assessment in patients with acute coronary syndrome (ACS). The key finding was that, beyond detecting coronary stenosis, CCTA-derived plaque characterization and high-risk features can improve risk stratification and potentially guide selection for invasive coronary angiography. Clinically, it frames how energy-resolved/advanced CCTA plaque metrics may influence management decisions in ACS.

Miceli AL, Iroulart JM, Domenech P et al. · Current problems in cardiology · (2026) · View on PubMed ↗

[Coronary CT angiography: Diagnosis, prognosis and PCI planning].

This 2026 review article summarized the evolving role of coronary CT angiography (CCTA) in diagnosis, prognosis, and percutaneous coronary intervention (PCI) planning. It found that CCTA improves beyond calcium scoring by visualizing non-calcified plaque and that prognosis is better predicted by overall atherosclerotic burden and high-risk plaque features (e.g., pericoronary fat) than by stenosis severity alone, informing updates such as revisions to CAD-RADS. Scientifically and clinically, the review supports using CCTA not only for anatomical assessment but also for functional evaluation (including CT-derived fractional flow reserve) and for guiding PCI planning.

Delapierre A, Tonnerre G, Mokrane FZ et al. · Annales de cardiologie et d’angeiologie · (2026) · View on PubMed ↗

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CT-Guided Intervention Planning (PCI/Procedural Workflows)

CT-guided PCI: From diagnosis to treatment planning.

This review studied computed tomography–guided percutaneous coronary intervention (CT-guided PCI) as an extension of coronary CT angiography (CCTA) from diagnosis to procedural planning. The key finding is that integrating morphological and CT-derived physiological information (including myocardial mass quantification and CT-derived physiology with 3D co-registration) can support individualized revascularization planning before PCI, with photon-counting CT expected to further refine accuracy. Clinically, this framework aims to improve procedural planning and potentially outcomes by making CT more actionable for intervention planning.

Ohashi H, Tajima A, Sakai K et al. · Journal of cardiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Machine Learning / Radiomics Using PCD-CT Spectral Data

Photon-counting Detector CT Spectral Reconstructions for Radiomics-based Liver Lesion Classification: A Multicenter Study.

This multicenter study evaluated radiomics-based machine learning for classifying benign versus malignant focal liver lesions in patients scanned with photon-counting detector CT (PCD-CT) at two institutions. Using multispectral virtual monochromatic images and material decomposition images derived from contrast-enhanced PCD-CT, and automatic lesion segmentation with a nnU-Net model, the study assessed diagnostic performance for liver lesion classification. The results are significant because they test whether PCD-CT spectral reconstructions can improve noninvasive liver tumor characterization beyond conventional CT.

Pietsch FL, Vellala AK, Haag F et al. · Investigative radiology · (2026) · 1 citations · View on PubMed ↗

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Oncology Imaging with PCD-CT (Metastases, Lesion Characterization, Treatment Response)

Photon-counting detector CT for follow-up after TACE in hepatocellular carcinoma: effects of reconstruction kernel and sharpness.

This retrospective study evaluated photon-counting detector CT (PCD-CT) reconstruction settings in 72 patients with hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE), comparing body regular (Br) versus quantitative regular (Qr) kernels across sharpness levels (36, 40, 44, 48) for residual viable tumor conspicuity. The key finding was that reconstruction kernel and sharpness materially affected image noise and signal-to-noise characteristics, thereby changing the visibility of residual viable tumor on post-TACE imaging. These results support optimizing PCD-CT reconstruction parameters to improve follow-up assessment of treatment response in HCC after TACE.

Yuan M, Wang D, Shi Z et al. · Abdominal radiology (New York) · (2026) · View on PubMed ↗ · Free PDF ↗

Optimization of spectral photon-counting CT reconstruction parameters for improved detection of peritoneal metastases compared with energy-integrating detector dual-energy CT: a phantom study.

This phantom study compared spectral photon-counting CT (SPCCT) with energy-integrating detector dual-energy CT (EID-DECT) for detecting peritoneal metastases using 40 keV virtual monoenergetic images (VMIs). By varying SPCCT reconstruction kernels (STD-B, HRB) and iDose4 levels (i5/i7/i9/i11) and analyzing noise power spectrum (NPS), task-based transfer function (TTF), and detectability indices (d’) for non-mucinous and mucinous metastases, the authors identified an optimal reconstruction-parameter combination that improved peritoneal metastasis detectability versus the comparator protocol. This provides actionable reconstruction guidance to enhance SPCCT performance for peritoneal metastasis detection in clinical imaging workflows.

Greffier J, Grange R, Dabli D et al. · European radiology experimental · (2026) · View on PubMed ↗ · Free PDF ↗

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Temporal Bone & ENT Imaging with PCD-CT

Photon-counting detector computed tomography for temporal bone: does higher resolution matter?

This narrative review summarized emerging evidence on photon-counting detector CT (PCD-CT) for temporal bone imaging, focusing on whether improved spatial resolution translates into clinically meaningful benefits compared with conventional energy-integrating detector CT (EID-CT). The key finding was that the temporal bone’s submillimeter anatomy makes it a sensitive testbed, but the literature is still developing regarding which resolution gains improve diagnostic outcomes in routine practice. The review’s significance is guiding clinicians and researchers on where higher-resolution PCD-CT is likely to matter most for temporal bone pathology assessment.

Epperson MV, Leng S, Lane JI et al. · Current opinion in otolaryngology & head and neck surgery · (2026) · View on PubMed ↗ · Free PDF ↗

Low-dose ultra-high-resolution temporal bone imaging using Sn100 kVp photon-counting CT: A comparative study with conventional CT.

This prospective comparative study evaluated low-dose ultra-high-resolution temporal bone imaging using Sn100 kVp photon-counting CT (PCD-CT) in patients with suspected or confirmed temporal bone lesions, comparing PCD reconstructions at 0.2 mm (PCD-0.2) and 0.6 mm (PCD-0.6) slice thicknesses against retrospectively retrieved conventional EID-CT at 120 kVp. The key finding was that PCD-CT enabled substantial radiation dose reduction while maintaining or improving image quality for temporal bone assessment, with finer 0.2 mm reconstructions supporting ultra-high-resolution visualization. This supports adopting low-dose PCD-CT protocols for temporal bone imaging where submillimeter detail is clinically important.

Tong J, Tian X, Huang Y et al. · European journal of radiology · (2026) · View on PubMed ↗

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Pediatric Dynamic Airway Imaging

Advanced Imaging to Assess Airway Dynamics.

This narrative review studied imaging methods for pediatric dynamic airway assessment, contrasting endoscopy with four-dimensional CT, photon-counting CT, and MRI techniques. It found that 4D CT can objectively quantify tracheal collapse during free breathing, photon-counting CT can achieve near–radiography-level effective doses for serial monitoring, and MRI can provide radiation-free dynamic assessment (including cine and retrospectively gated submillimeter approaches). These advances are significant because they offer less invasive, more objective alternatives for diagnosing and monitoring dynamic airway disorders in children.

Bates AJ, Fleck RJ, Smith DF · Otolaryngologic clinics of North America · (2026) · View on PubMed ↗

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Neurovascular Imaging & Aneurysm Measurement with PCD-CTA

3D Volume Rendering of Ultrahigh-Resolution Photon-Counting Detector CT Angiography for Preoperative Assessment of Intracranial Aneurysms: Initial Experience.

This retrospective initial-experience study assessed whether combining ultrahigh-resolution photon-counting detector CT angiography (UHR PCD-CTA) with 3D volume rendering (3DVR) yields reliable morphologic assessment and reproducible aneurysm size measurements for preoperative intracranial aneurysm evaluation. In 21 patients with 32 aneurysms, two neurosurgeons evaluated 2D UHR and 3DVR datasets, and the combined approach showed sufficient image quality and measurement reproducibility for preoperative characterization. The results support integrating UHR PCD-CTA with 3DVR as a practical imaging workflow to improve pre-surgical planning for intracranial aneurysms.

Tóth A, Silbergleit M, Al Kasab S et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗

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Musculoskeletal & Orthopedic Applications (Implants, Bone Remodeling, Spine)

Evaluating osseointegration, bone remodeling and osteolysis after total wrist arthroplasty using photon-counting detector CT.

This study evaluated osseointegration, bone remodeling, and periprosthetic osteolysis after total wrist arthroplasty in 19 patients using photon-counting detector CT (PCD-CT) at day 1, 6 months, and 12 months. Osseointegration (bone ingrowth to the implant) increased across most implant zones over time, with cortical thickness and cortical density quantified around the implant and periprosthetic osteolysis assessed by zone. These findings support PCD-CT as a quantitative imaging tool for monitoring implant integration and osteolysis risk after wrist arthroplasty.

Kämmerling N, Farnebo S, Lind G et al. · Skeletal radiology · (2026) · View on PubMed ↗ · Free PDF ↗

Metal Artifact Reduction in Lumbar Spine Instrumentation: A Comparison of Photon-Counting Detector-Computed Tomography Versus Energy-Integrating Detector-Computed Tomography, Iterative Metal Artifact Reduction, and Virtual Monoenergetic Imaging in 100 Examinations.

This retrospective study compared photon-counting detector CT (PCD-CT) versus energy-integrating detector CT (EID-CT) for metal artifact reduction in 100 lumbar spine instrumentation examinations after fusion surgery (50 EID and 50 PCD). The key finding was that PCD-CT virtual monoenergetic images (VMIs), including reconstructions using tin (Sn) filtration and iterative metal artifact reduction (iMAR), were evaluated qualitatively and quantitatively against EID-CT and other approaches for artifact suppression. This is significant because improved artifact reduction can enhance postoperative assessment and measurement accuracy in patients with spinal hardware.

Marth T, Marth AA, Abel F et al. · Investigative radiology · (2026) · 2 citations · View on PubMed ↗

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Myelography & CSF-Venous Fistula Detection

Photon-Counting Detector vs Energy-Integrating Detector CT Myelography for Detecting CSF-Venous Fistulas in Spontaneous Intracranial Hypotension: Substantially Lower Radiation Dose.

This retrospective single-center cohort study compared photon-counting detector CT myelography (PCD-CTM) versus energy-integrating detector CT myelography (EID-CTM) for detecting CSF-venous fistulas in 603 patients with spontaneous intracranial hypotension (SIH). The key finding was that PCD-CTM substantially reduced session radiation dose-length product (DLP) for the entire CT myelography examination compared with EID-CTM. This is clinically significant because it supports lower-dose imaging for a common diagnostic pathway in SIH while maintaining the ability to detect CSF-venous fistulas.

Christensen S, Kranz PG, Malinzak MD et al. · AJNR. American journal of neuroradiology · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗

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Body Composition & Metabolic Risk from PCD-CT

A Prediction Model for Metabolic Abnormality Clustering Based on Abdominal Body Composition Parameters From Photon-counting CT: Development and Internal Validation.

This retrospective study of 116 abdominal PCCT patients (61 with metabolic abnormality clustering and 55 without) investigated whether PCCT-derived abdominal body composition parameters are associated with metabolic abnormality clustering and developed clinical, imaging, and combined prediction models. The key result was that abdominal body composition metrics derived from photon-counting CT improved prediction of metabolic abnormality clustering, and the internally validated models supported their use for risk assessment. Clinically, this suggests PCCT-based body composition analysis could help identify patients at higher metabolic risk using imaging biomarkers.

Zhang Y, Weng S, Liu Y et al. · Academic radiology · (2026) · View on PubMed ↗

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Material Quantification & Physical Density Estimation (Zeff/ρeff/Surrogates)

Single-Phase Surrogate for True Non-Contrast Liver CT Using 190-keV Monoenergetic Imaging on Photon-Counting CT: Implications for Hepatic Steatosis Assessment.

This retrospective analysis tested whether 190-keV virtual monoenergetic imaging (VMI) derived from photon-counting detector CT (PCD-CT) can act as a surrogate for true non-contrast (TNC) liver CT for hepatic steatosis quantification, using MRI-proton density fat fraction (PDFF) as the reference in 49 patients. The key finding was that 190-keV VMI showed strong attenuation agreement with TNC (and improved practical non-contrast estimation) for segmental liver measurements used in steatosis assessment. Scientifically and clinically, this enables steatosis quantification workflows that approximate TNC without requiring a separate true non-contrast acquisition.

Ohtani T, Shimada M, Nishiyama K et al. · Academic radiology · (2026) · View on PubMed ↗ · Free PDF ↗

An algorithm to calculate physical density of biomedical objects having 3 ≤ Zeff ≤ 20: an application study using clinical photon-counting computed tomography equipment.

This methodological study proposed an algorithm to calculate effective physical density (ρeff) for biomedical objects with effective atomic number (Zeff) between 3 and 20, using clinical photon-counting CT equipment and fitting interaction cross sections to measured linear attenuation coefficients derived from virtual monochromatic images (VMIs). The key finding was that incorporating Zeff into the analysis improved the estimation of ρeff from photon-counting CT–derived attenuation data. Scientifically, this supports more quantitative, material-relevant imaging outputs from photon-counting CT beyond conventional Hounsfield units.

Hayashi H, Nishigami R, Asahara T et al. · Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine · (2026) · 3 citations · View on PubMed ↗ · Free PDF ↗

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Neonatal/Perinatal Imaging & Device Positioning

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

This study assessed three smaller supraglottic airway device prototypes (Neo i-gel sizes 0.65, 0.75, 0.85) plus the smallest commercial i-gel size 1.0 in stillborn low-birth-weight neonates (>500 g) using photon-counting CT to measure device positioning relative to perilaryngeal landmarks and adjacent structures. The key finding was that photon-counting CT enabled precise anatomical placement evaluation of these ultra-small devices, informing feasibility of positioning in very small neonatal airways. Clinically, this supports selecting and refining supraglottic airway device sizes for neonatal resuscitation and surfactant delivery in extremely low-birth-weight infants.

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

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Generated automatically on October 05, 2026. Covers PubMed articles published September 28, 2026 – October 05, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.