What’s New in Photon Counting CT?

October 02, 2026 · 24 articles · 14 research themes · covering September 25, 2026 – October 02, 2026

Overview

Across this week’s set of papers, a dominant theme is that photon-counting CT (PCD/PCCT) is moving from “better images” toward more actionable, quantitative outputs—often by pairing spectral information with optimized reconstruction settings. Multiple studies compare PCCT/PCD-CT with conventional energy-integrating CT (EID-CT) for dose–quality tradeoffs (e.g., peritoneal metastasis detection, multiple myeloma bone lesion imaging, and 4D parathyroid imaging), while others show that the reconstruction pipeline—kernel choice, sharpness, virtual monoenergetic energies, and metal-artifact reduction—materially changes diagnostic performance (e.g., residual viable tumor conspicuity after TACE and visualization around spinal hardware). Methodologically, work on energy-dependent attenuation behavior and new quantitative density approaches (effective physical density incorporating effective atomic number) underscores a push toward more standardized, physics-informed biomarkers rather than relying solely on conventional Hounsfield-unit heuristics.

A second major thread is clinical translation in cardiology and oncology using CT beyond simple anatomy. Reviews emphasize that coronary CT angiography (CCTA) and high-risk plaque features—augmented by CT-derived physiology such as FFR-CT—can improve prognosis and guide management, while opportunistic CAC detection on non-cardiac scans is increasingly framed as a workflow-level risk stratification tool (with the caveat that outcome trials are still needed). In oncology, spectral PCCT features are being leveraged for noninvasive lesion characterization via radiomics/AI (focal liver lesion benign vs malignant classification) and for improved detection/monitoring of disease (peritoneal metastases, HCC after TACE, and bone involvement in multiple myeloma). Finally, several studies highlight targeted applications where PCCT’s spatial resolution and dose efficiency may matter most—temporal bone imaging, neurovascular planning (intracranial aneurysms), and pediatric/dynamic airway assessment—alongside practical considerations like patient positioning (off-centering) that influence dose and noise.

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Photon-Counting CT vs Energy-Integrating CT (Comparative Performance & Dose)

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 sharpness and radiation dose (CTDIvol) in patients with bone lesions from multiple myeloma (MM). Across 5 included studies (n=170 patients), PCD-CT was evaluated for dose–image-quality tradeoffs relative to EID-CT, with evidence quality assessed using ROBINS-I and GRADE. If PCD-CT consistently improves sharpness at lower dose in MM lesion imaging, it could support safer longitudinal monitoring of skeletal disease.

Ohannesian VA, Taneja BC, do Amaral E Castro A et al. · Skeletal radiology · (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.

In a spectral phantom study, the investigators compared spectral photon-counting CT (SPCCT) versus energy-integrating detector dual-energy CT (EID-DECT) for detecting peritoneal metastases on 40 keV virtual monoenergetic images (VMIs), optimizing SPCCT reconstruction kernels (STD-B, HRB) and iDose4 levels (i5/i7/i9/i11) using noise power spectrum (NPS) and task-based transfer function (TTF). They found that specific SPCCT reconstruction parameter combinations improved detectability (d’) for non-mucinous and mucinous peritoneal metastases relative to the EID-DECT reference reconstruction settings. These results provide practical reconstruction guidance for SPCCT protocols aimed at more sensitive peritoneal metastasis detection.

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

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Photon-Counting CT Reconstruction Optimization (Kernels, Sharpness, VMIs, iMAR)

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 36–48) in 72 patients with hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE) follow-up, focusing on residual viable tumor conspicuity. The key finding was that reconstruction kernel and sharpness materially affected image noise and signal-to-noise characteristics, which in turn changed the visibility of residual viable tumor on post-TACE imaging. These results support optimizing PCD-CT reconstruction parameters to improve detection of residual viable HCC and thereby strengthen clinical follow-up assessment after TACE.

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

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Spectral/Material Decomposition & Virtual Monoenergetic Imaging (Quantitative Imaging Biomarkers)

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 in 49 patients, comparing attenuation agreement with virtual non-contrast (VNC) and correlation with MRI-proton density fat fraction (PDFF). The key finding was that 190-keV VMI showed strong attenuation agreement with TNC (and improved correspondence for steatosis-related quantification) compared with alternative virtual approaches. Clinically, this could enable steatosis assessment without requiring a dedicated true non-contrast scan, reducing patient burden while leveraging energy-resolved PCD-CT.

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 interaction cross-section fitting to measured linear attenuation coefficients derived from virtual monochromatic images on clinical photon-counting CT equipment. The key finding was that incorporating Zeff into the fitting workflow enabled estimation of ρeff across the specified Zeff range using photon-counting CT-derived virtual monochromatic data. This supports more quantitative, material-relevant imaging outputs from photon-counting CT that could improve standardization of density-based biomarkers.

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 ↗

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 evaluated how energy-resolved attenuation on dual-source photon-counting CT (PCD-CT) affects quantitative assessment of femoral bone marrow in 103 patients with multiple myeloma, using virtual monoenergetic images reconstructed at 40–190 keV. The key finding was that femoral bone marrow attenuation varied with photon energy, which has direct implications for threshold-based differentiation between physiological tissue and myeloma infiltration. Scientifically and clinically, it indicates that quantitative myeloma assessment should account for energy-dependent attenuation behavior when selecting thresholds and reconstruction energies.

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

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Radiomics & AI/ML Using Photon-Counting CT Spectral Features

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

This multicenter study evaluated whether photon-counting detector CT (PCD-CT) spectral reconstructions improve radiomics-based machine learning classification of focal liver lesions into benign versus malignant. Using multispectral virtual monochromatic images and material decomposition images from contrast-enhanced PCD-CT at two institutions, lesions were automatically segmented with a nnU-Net model, and the study assessed diagnostic performance of the radiomics classifiers. If validated, PCD-CT–derived spectral features could enhance noninvasive liver lesion characterization compared with conventional CT, improving diagnostic accuracy and potentially reducing unnecessary biopsies.

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

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Cardiac CT Angiography & Coronary Plaque/Physiology (CCTA, FFR-CT, High-Risk Plaque)

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), emphasizing how plaque characterization and non-coronary causes of chest pain can guide care. The key finding was that beyond detecting coronary stenosis, CCTA-derived high-risk plaque features and risk stratification metrics have evidence supporting improved prognostic assessment and potential patient selection for invasive angiography. Clinically, it positions CCTA as a broader risk-management tool in ACS rather than a purely anatomic stenosis test.

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

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

This 2026 review studied how advanced quantitative cardiac CT—combining coronary stenosis quantification, plaque quantification, and fractional flow reserve derived from CT (FFR-CT)—can improve coronary artery disease (CAD) assessment beyond conventional cardiac CT angiography (CCTA). The key finding is that AI-based quantitative CT can provide more reproducible plaque biomarkers and stenosis measurements to enable more refined cardiovascular risk stratification and potentially reduce interobserver variability. Clinically, integrating these quantitative and physiology-informed CT metrics could improve patient selection for preventive therapies and downstream management, though the review emphasizes ongoing workflow and evidence needs.

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

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

This 2026 narrative review summarizes how coronary CT angiography (CCTA) is used across diagnosis, prognosis, and percutaneous coronary intervention (PCI) planning in patients with coronary artery disease. It highlights that CCTA improves on calcium scoring by visualizing non-calcified plaque and that CT-derived functional measures such as fractional flow reserve, along with plaque burden/morphology (e.g., high-risk plaque and pericoronary fat), better predict cardiovascular events than stenosis severity alone, informing updates such as revised CAD-RADS classification. Clinically, the review supports using CCTA not only for triage but also for risk stratification and procedural planning to guide management decisions.

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

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Opportunistic Coronary Artery Calcium (CAC) Detection on Non-Cardiac CT

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

This review studied the emerging role of opportunistic coronary artery calcium (CAC) detection on existing thoracic CT scans (including routine thoracic CT, lung cancer screening CT, and attenuation-correction CT) and how AI/ML may expand its use. The key finding is that identifying CAC on non-cardiac CT can improve cardiovascular risk assessment and identify patients who may benefit from preventive medical therapy, despite the lack of randomized trials demonstrating clinical outcome impact. Scientifically and clinically, this supports a growing evidence base for integrating CAC into broader imaging workflows while highlighting the need for outcome-driven trials.

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

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Photon-Counting CT in Oncology (Liver, Peritoneum, Bone Lesions, HCC Follow-up)

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 photon-counting CT (PCCT) patients (61 with metabolic abnormality clustering and 55 without) examined how PCCT-derived abdominal body composition parameters relate to clustering of metabolic abnormalities defined as ≥2 of hyperglycemia, hypertension, hypertriglyceridemia, and low HDL-C. The authors developed and internally validated clinical, imaging, and combined prediction models to estimate risk of metabolic abnormality clustering using these PCCT body composition metrics. If externally validated, PCCT-based body composition phenotyping could improve early identification of patients at high cardiometabolic risk beyond standard clinical variables.

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

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Photon-Counting CT for Neurovascular & Intracranial Pathology (Aneurysm, SIH fistulas)

CT-guided PCI: From diagnosis to treatment planning.

This retrospective single-center cohort study compared radiation dose between photon-counting detector CT myelography (PCD-CTM) and energy-integrating detector CT myelography (EID-CTM) for detecting cerebrospinal fluid–venous fistulas (CVFs) in patients with spontaneous intracranial hypotension (SIH). Among 603 CTM examinations (EID-CTM n=470; PCD-CTM n=133, 2020–2025), the primary endpoint was session dose-length product (DLP) for the entire CTM examination, with the study reporting substantially lower radiation dose for PCD-CTM. This is clinically significant because it supports safer imaging for SIH patients who may require repeated or serial evaluations.

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

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

This retrospective initial-experience study evaluated whether combining ultrahigh-resolution photon-counting detector CT angiography (UHR PCD-CTA) with 3D volume rendering (3DVR) yields reliable morphologic assessment and reproducible size measurements for preoperative intracranial aneurysm evaluation. Across 32 aneurysms in 21 patients, two neurosurgeons assessed 2D UHR and 3DVR datasets for image quality and aneurysm characterization, with the study focusing on measurement reproducibility. If confirmed in larger cohorts, UHR PCD-CTA plus 3DVR could enhance preoperative planning by providing more accurate and consistent aneurysm sizing and visualization.

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

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Photon-Counting CT for Endocrine/Neck Imaging (Parathyroid, Myelography)

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

This study quantitatively compared photon-counting CT (PCCT) with energy-integrating detector CT (EIDCT) for image quality and radiation output in 4D parathyroid imaging. In the context of repeated noncontrast and multiphase contrast-enhanced acquisitions, it measured CTDIvol and DLP and assessed image quality using signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The significance is that PCCT could reduce radiation exposure while maintaining or improving neck imaging quality, potentially enabling safer 4DCT-based localization of parathyroid pathology.

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

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Photon-Counting CT for Spine & Musculoskeletal Imaging (Metal artifacts, Bone marrow, Orthopedics)

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

This prospective observational study examined 19 patients after total wrist arthroplasty using photon-counting detector CT (PCD-CT) on postoperative day 1 and at 6 and 12 months to evaluate osseointegration, bone remodeling, and periprosthetic osteolysis. The key finding was that PCD-CT enabled visualization and quantification of bone ingrowth (osseointegration) and measurement of cortical thickness/density and osteolysis across predefined zones around the implant over time. Clinically, this supports PCD-CT as a tool for monitoring implant integration and early periprosthetic complications 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 lumbar spine instrumentation, including evaluation of virtual monoenergetic images (VMIs) with tin filtration (Sn) and iterative metal artifact reduction (iMAR). Using 100 clinical post-lumbar-fusion scans (50 EID and 50 PCD), it assessed qualitative and quantitative performance of PCD-CT reconstructions for reducing metal artifacts. If PCD-CT with spectral VMIs and iMAR improves visualization around hardware, it could enhance postoperative assessment and reduce diagnostic uncertainty in spine imaging.

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

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Temporal Bone Imaging with Photon-Counting CT (Resolution vs Clinical Benefit)

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 (vs conventional energy-integrating detector CT) translates into meaningful clinical decision-making. The key finding was that while PCD-CT offers higher resolution and potentially better depiction of submillimeter temporal bone structures, the literature is still developing and definitive outcome-driven superiority over conventional CT remains to be established. Scientifically, it frames where higher-resolution PCD-CT may matter most (e.g., fine bony anatomy) and where clinical benefit evidence is currently limited.

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.

In a prospective study of patients with suspected or confirmed temporal bone lesions, this work compared low-dose ultra-high-resolution temporal bone imaging using Sn100 kVp photon-counting CT (PCD-CT) reconstructed at 0.2 mm and 0.6 mm slice thicknesses against prior conventional energy-integrating detector CT (EID-CT) at 120 kVp. The key finding was that PCD-CT could achieve comparable or improved image quality for temporal bone evaluation while enabling radiation dose reduction, with slice thickness affecting the balance between detail and noise. This supports adopting photon-counting CT protocols for temporal bone imaging where submillimeter anatomy 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 (4DCT, Photon-Counting CT, MRI alternatives)

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. The key finding was that photon-counting CT enabled precise anatomical placement assessment and showed differences in how the prototypes positioned relative to adjacent structures compared with the smallest available i-gel. Scientifically, this supports using photon-counting CT for preclinical airway device evaluation in very small neonates where conventional imaging/fit assessment is limited.

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

Advanced Imaging to Assess Airway Dynamics.

This narrative review studied imaging approaches for pediatric dynamic airway assessment, focusing on four-dimensional CT (4DCT), photon-counting CT, and MRI techniques for airway motion and collapse. It found that 4DCT enables objective quantification of tracheal collapse during free breathing, photon-counting CT can deliver effective doses approaching chest radiography for serial monitoring, and MRI can provide radiation-free dynamic evaluation (including cine and retrospectively gated submillimeter methods). These advances are significant because they offer less invasive, more reproducible alternatives to endoscopy 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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Patient Positioning & Dose Optimization in PCCT (Off-centering, Protocols)

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

This phantom study investigated 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, 5-year-old) scanned on a commercial PCCT system at multiple vertical offsets, it quantified dose and noise changes to determine sensitivity to patient positioning. The findings are significant because they inform positioning protocols and dose optimization strategies for PCCT in both adult and pediatric imaging.

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

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Clinical Case Reports Using Photon-Counting CT

Photon-counting CT of midventricular takotsubo cardiomyopathy.

This Radiology Case Reports article describes a 63-year-old woman with acute chest pain and elevated cardiac troponin I after emotional stress, where photon-counting detector coronary CT angiography (PCD-CCTA) was used to evaluate suspected midventricular takotsubo cardiomyopathy. The key finding was that PCD-CCTA excluded obstructive coronary artery disease and, with multiphase cine reconstructions, clearly demonstrated the characteristic midventricular wall-motion abnormality pattern with basal and apical sparing. This highlights the diagnostic value of photon-counting coronary CT for rapid, comprehensive assessment of stress cardiomyopathy variants in the acute setting.

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

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Generated automatically on October 02, 2026. Covers PubMed articles published September 25, 2026 – October 02, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.