What’s New in Photon Counting CT?

October 04, 2026 · 25 articles · 15 research themes · covering September 27, 2026 – October 04, 2026

Overview

This week’s PubMed set is dominated by a practical theme: photon-counting CT’s advantages are increasingly being translated into actionable protocol choices—how to position patients, select reconstruction kernels/sharpness, and tune virtual monoenergetic energies to balance dose, noise, and diagnostic task performance. Phantom and clinical studies show that seemingly small workflow variables (e.g., vertical off-centering) can measurably shift both radiation output and image noise, while reconstruction parameters can materially change lesion conspicuity after interventions (e.g., post–TACE HCC follow-up) or improve detectability for challenging targets (e.g., peritoneal metastases). Complementing this, multiple investigations emphasize “quantitative” uses of PCD-CT: VMI-based surrogates for non-contrast imaging for hepatic steatosis, energy-dependent attenuation behavior that affects thresholding in myeloma, and methods to derive effective physical density from spectral data.

A second major thread is moving beyond anatomy toward risk and decision support—especially in cardiac imaging. Reviews and studies highlight that modern CCTA value comes from plaque characterization and CT-derived physiology (including FFR-CT concepts), with prognosis tied more to overall atherosclerotic burden and high-risk plaque features than stenosis severity alone. Related work frames how CT-guided PCI planning can integrate morphological and physiological information, and how opportunistic CAC detection could scale prevention strategies using AI/ML. In parallel, machine learning/radiomics papers demonstrate that spectral PCD-CT features can improve classification (e.g., benign vs malignant liver lesions) and enable imaging biomarkers for metabolic abnormality clustering.

Finally, the dataset underscores breadth of clinical translation: improved temporal bone visualization at very fine slice thicknesses with reduced dose (including Sn100 kVp PCD-CT), better handling of metal artifacts in spine instrumentation, and lower-dose CT myelography for CSF-venous fistula detection in spontaneous intracranial hypotension. Across special populations and devices—pediatric dynamic airway assessment, neonatal airway device positioning, and intracranial aneurysm preoperative measurement—PCD-CT is repeatedly positioned as a tool for precision imaging with dose efficiency, though several reviews note that definitive outcome advantages still require more comparative clinical evidence.

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Photon-Counting CT (PCD/PCCT) Physics, Reconstruction & Dose Optimization

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—body regular (Br) vs quantitative regular (Qr) kernels and sharpness levels (36, 40, 44, 48)—for triple-phase follow-up imaging after transarterial chemoembolization (TACE) in 72 patients with hepatocellular carcinoma (HCC). The key finding was that reconstruction kernel and sharpness materially affected image noise and residual viable tumor conspicuity, with specific settings improving the visibility of residual viable tumor for post-TACE assessment. These results support optimizing PCD-CT reconstruction parameters to enhance clinical follow-up detection of residual HCC after TACE.

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

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

This study used photon-counting CT to assess anatomical positioning of the smallest commercially available i-gel size 1.0 and three smaller Neo i-gel prototypes (sizes 0.65, 0.75, 0.85) in stillborn low-birth-weight neonates weighing >500 g. The key finding was that photon-counting CT enabled precise measurement of device placement relative to perilaryngeal landmarks and characterization of effects on adjacent structures across the prototype sizes. Clinically, this supports selecting or refining supraglottic airway device sizes for neonatal resuscitation and surfactant delivery in very small infants.

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

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 conventional energy-integrating detector CT (EIDCT). The key finding was that PCCT improved dose efficiency and image quality metrics—assessed using CTDIvol and DLP for radiation output and SNR/contrast-to-noise ratio for image quality. This is significant because it addresses the high cumulative dose of multiphase 4DCT protocols while preserving or enhancing visualization of anatomically complex neck targets.

Arizono E, Buch K, Kelly HR et al. · AJNR. American journal of neuroradiology · (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), including iterative metal artifact reduction (iMAR) and virtual monoenergetic imaging (VMI) approaches, for metal artifact reduction in lumbar spine instrumentation. In 100 clinical scans after lumbar spine fusion surgery (50 EID and 50 PCD) using tin (Sn) filtration, the key finding was the relative performance of PCD-CT–based spectral reconstructions (VMIs) and iMAR/technique combinations in reducing metal artifacts quantitatively and qualitatively. Scientifically and clinically, the results support selecting PCD-CT spectral reconstructions to improve postoperative assessment quality in patients with spinal hardware.

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

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 on a commercial PCCT system at multiple vertical offsets. Vertical off-centering measurably changed both radiation 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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Virtual Monoenergetic / Virtual Non-Contrast (VMI/VNC) Imaging for Quantification

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 study tested whether 190-keV virtual monoenergetic imaging (VMI) from photon-counting detector CT (PCD-CT) can act as a surrogate for true non-contrast (TNC) CT in 49 patients undergoing abdominal PCD-CT and MRI-proton density fat fraction (PDFF) for hepatic steatosis assessment. The key finding was that 190-keV VMI showed strong attenuation agreement with TNC (and was compared against virtual non-contrast, VNC) across liver segments, supporting its use for steatosis quantification when true non-contrast imaging is not feasible. Scientifically and clinically, this could reduce scanning burden while preserving quantitative accuracy for hepatic fat assessment using PCD-CT.

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

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Material/Effective Density & Spectral Quantitative Methods

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. The key finding was that ρeff could be derived by fitting interaction cross sections to measured linear attenuation coefficients obtained from virtual monochromatic images (VMIs), with Zeff used as feedback to improve the density estimation. This supports more quantitative, material-relevant imaging outputs from photon-counting CT for biomedical research and potential clinical applications.

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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Image Quality Metrics & Detectability (NPS/TTF/d’)

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

This 2026 review article synthesized evidence on coronary CT angiography (CCTA) for diagnosis, prognosis, and percutaneous coronary intervention (PCI) planning in patients with coronary artery disease. It highlights that CCTA moves from calcium-score triage to direct visualization of non-calcified plaque and integrates functional assessment via CT-derived fractional flow reserve, while prognosis is better predicted by overall atherosclerotic burden and high-risk plaque features than by stenosis severity alone. The review’s significance is that it frames how modern CCTA findings (including CAD-RADS updates) can guide both risk assessment and PCI planning.

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

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) reconstruction settings with energy-integrating detector dual-energy CT (EID-DECT) for detecting peritoneal metastases on 40 keV virtual monoenergetic images (VMIs). Using noise power spectrum (NPS), task-based transfer function (TTF), and detectability indices (d’) for non-mucinous and mucinous peritoneal metastases, the authors identified an optimal combination of SPCCT kernel (STD-B or HRB) and iDose4 level (i5/i7/i9/i11) that improved detectability relative to the EID-DECT reference reconstruction. Scientifically, this provides actionable reconstruction-parameter guidance to enhance peritoneal metastasis detection with SPCCT.

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

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Oncologic Imaging with PCD-CT (Liver, Peritoneum, Bone Lesions)

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 investigated energy-resolved attenuation behavior of femoral bone marrow on dual-source photon-counting CT in 103 patients with multiple myeloma, using virtual monoenergetic images reconstructed at 40–190 keV. The key finding was that bone marrow attenuation varied with photon energy, which has direct implications for threshold-based quantitative differentiation between physiological marrow and myeloma infiltration. Scientifically and clinically, it indicates that quantitative CT thresholds for myeloma assessment must account for the chosen VMI energy to avoid misclassification.

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

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 bone lesions from multiple myeloma (MM). Across five included comparative studies (n=170 patients), the key outcome was the relative performance of PCD-CT on sharpness and CTDIvol versus EID-CT, with evidence quality assessed using ROBINS-I and GRADE. The results are clinically relevant because they quantify whether PCD-CT can improve diagnostic image quality while reducing radiation exposure in MM patients undergoing CT-based assessment of bone disease.

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

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Cardiac CT Angiography & Coronary Risk/Prognosis (CCTA/FFR-CT/CAC)

Photon-counting CT of midventricular takotsubo cardiomyopathy.

This report described a 63-year-old woman with acute chest pain and elevated troponin I after emotional stress, evaluated for midventricular takotsubo cardiomyopathy using photon-counting detector coronary CT angiography (PCD-CCTA). The key finding was that PCD-CCTA excluded obstructive coronary artery disease and, with multiphase cine reconstructions, clearly characterized the midventricular circumferential wall-motion abnormality with basal and apical sparing. This demonstrates the potential value of photon-counting coronary CT as a “one-stop” diagnostic tool to distinguish takotsubo cardiomyopathy from obstructive coronary causes of acute coronary syndrome.

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

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

This article is a review evaluating 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 (high-risk features) and assessment of non-coronary causes can improve patient selection for invasive angiography and inform prognosis. Clinically, it consolidates evidence supporting CCTA as a broader risk-stratification tool in ACS rather than a stenosis-only test.

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

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 tin-filtration photon-counting CT (PCD-CT) versus conventional energy-integrating CT (EID-CT) in patients with suspected or confirmed temporal bone lesions. The key finding was that PCD-CT achieved improved image quality at very fine reconstruction slice thicknesses (0.2 mm and 0.6 mm) while reducing radiation dose compared with the 120 kVp EID-CT reference. This suggests that Sn100 kVp PCD-CT can enhance visualization of small temporal bone structures with lower patient exposure.

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

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

This review studied advanced quantitative cardiac 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 and stenosis biomarkers than conventional visual assessment, enabling more efficient risk stratification and potentially more physiologically grounded decision-making. Scientifically and clinically, this supports a shift from purely anatomic CCTA interpretation toward quantitative, AI-enabled imaging that may better predict major adverse cardiovascular events.

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 existing thoracic CT scans (including lung cancer screening CT, routine thoracic CT, and attenuation-correction CT). The key finding is that identifying CAC on thoracic CT can improve cardiovascular risk assessment and guide preventive therapy, despite the absence (at present) of randomized trials proving clinical outcome benefit. The scientific significance is that it positions AI/ML-enabled CAC detection as a scalable way to integrate cardiovascular risk screening into existing imaging pathways.

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

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CT-Guided Interventions & Procedural Planning (including PCI/CT-guided PCI)

CT-guided PCI: From diagnosis to treatment planning.

This article reviewed CT-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 physiological information from CCTA—supported by advances in myocardial mass quantification, CT-derived physiology, and 3D co-registration—can enable individualized revascularization planning before PCI, with photon-counting CT proposed to further refine accuracy. This is significant because it frames how next-generation CT (including PCD-CT) may improve procedural planning and potentially outcomes in coronary intervention.

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

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Temporal Bone Imaging (Sn100kVp/Ultra-High Resolution)

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 and specifically addressed whether higher spatial resolution translates into meaningful clinical decision-making compared with conventional energy-integrating detector CT (EID-CT). The key finding was that PCD-CT’s improved resolution and noise characteristics are promising for submillimeter temporal bone structures, but definitive clinical outcome advantages remain incompletely established. Scientifically, it frames where higher-resolution PCD-CT may matter most (e.g., fine bony anatomy) and where further comparative studies are needed.

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

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Vascular Imaging in Trauma & Peripheral Arteries

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

This study assessed how virtual monoenergetic (VME) reconstructions from photon-counting detector CT (PCD-CT) affect the assessability of lower-extremity arteries in polytrauma patients undergoing a double-bolus protocol. The key finding was that specific VME energy levels provided sufficient vascular contrast (defined as >200 Hounsfield Units) to support evaluation of peripheral arterial pathology in extended trauma scans. Clinically, it helps optimize VME settings to improve vascular diagnostic confidence without requiring additional dedicated angiographic acquisitions.

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

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Musculoskeletal & Orthopedic Imaging (Implants, Bone Remodeling, Myeloma)

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 postoperatively. Osseointegration (bone ingrowth to the implant) increased across most periprosthetic zones over 12 months, with an exception noted in the capitate, alongside quantitative assessment of cortical thickness/density and zone-based osteolysis evaluation. These findings support PCD-CT as a tool for monitoring early implant integration and periprosthetic bone changes after wrist arthroplasty, potentially improving post-surgical surveillance.

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

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Myelography & Intracranial Hypotension (CSF-venous fistulas)

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 patients with spontaneous intracranial hypotension (SIH). Across 603 CT myelography examinations (470 EID-CTM, 133 PCD-CTM), the key finding was substantially lower session dose-length product (DLP) with PCD-CTM while maintaining the clinical goal of CVF detection. The clinical significance is that PCD-CTM may reduce radiation exposure for SIH patients undergoing repeated multiacquisition CT myelography.

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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Pediatric Dynamic Airway & Pediatric Imaging Protocols

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 for radiation-free or lower-dose dynamic evaluation. It highlights that 4D CT can objectively quantify tracheal collapse during free breathing, photon-counting CT can achieve effective doses approaching chest radiography for serial monitoring, and MRI cine/retrospective gating can provide submillimeter dynamic assessment without radiation. 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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Medical Devices & Neonatal/Resuscitation Applications

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 (UHR) photon-counting detector CT angiography (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 supported consistent aneurysm characterization and size measurement. The clinical significance is improved preoperative planning workflow for intracranial aneurysms using UHR PCD-CTA with 3DVR post-processing.

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

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Machine Learning, Radiomics & Imaging Biomarkers

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, with lesion segmentation performed by a nnU-Net model, the study found that spectral PCD-CT–derived features improved noninvasive lesion classification performance. Clinically, this supports PCD-CT spectral imaging combined with deep-learning segmentation and radiomics as a potential diagnostic aid for hepatic lesion characterization.

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

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 associations between PCCT-derived abdominal body composition parameters and metabolic abnormality clustering, and developed clinical, imaging, and combined prediction models with internal validation. The key result was that abdominal body composition metrics derived from PCCT improved prediction of metabolic abnormality clustering, enabling risk stratification beyond clinical variables alone. Clinically, this could support PCCT-based imaging biomarkers for earlier identification of patients at risk for clustered metabolic abnormalities.

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

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Generated automatically on October 04, 2026. Covers PubMed articles published September 27, 2026 – October 04, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.