What’s New in Photon Counting CT?

October 03, 2026 · 25 articles · 15 research themes · covering September 26, 2026 – October 03, 2026

Overview

This week’s PubMed set highlights how photon-counting CT (PCCT/SPCCT) is moving beyond “better images” toward controllable, task-specific optimization. Multiple phantom and methodological papers show that seemingly small technical choices—patient centering, reconstruction kernel, sharpness level, and energy selection—can materially change dose, noise, and detectability. Complementing this, studies on effective density estimation and energy-dependent attenuation emphasize that quantitative PCCT biomarkers require careful calibration to the chosen virtual monoenergetic energy.

Clinically, the dominant momentum is toward extracting more decision-relevant information from CT than stenosis or morphology alone. In coronary disease, narrative reviews converge on plaque burden and high-risk plaque features (plus CT-derived physiology such as FFR-CT) as key drivers of prognosis and procedural planning, with AI-based quantification framed as a way to improve reproducibility. In oncology and metabolic risk, spectral radiomics and body-composition biomarkers derived from PCCT are being tested for lesion characterization (e.g., liver), peritoneal metastasis detectability, and response assessment (e.g., post-TACE HCC), aiming to reduce invasive workups and missed residual disease.

Finally, several studies reinforce the “dose-efficiency” promise of photon counting in repeated or specialized imaging tasks—4D parathyroid imaging, CT myelography for spontaneous intracranial hypotension, dynamic airway assessment, and high-detail temporal bone imaging. Across musculoskeletal and orthopedic applications (implant integration, metal artifact reduction, spine hardware), PCCT is positioned as a quantitative follow-up tool that can support safer longitudinal monitoring.

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Photon-Counting CT Physics, Reconstruction & Dose Optimization

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 virtual monochromatic images (VMIs). The key finding was that ρeff could be derived by fitting interaction cross sections (σs) to measured linear attenuation coefficients (μs), with Zeff analyzed in advance and fed back into the density estimation. This provides a quantitative imaging tool that can improve material characterization and standardization for photon-counting CT–based density measurements across biological materials.

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 ↗

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, 5-year-old) scanned on a commercial PCCT system at multiple vertical offsets. Vertical off-centering changed both dose and image noise, with the magnitude of the effect varying by phantom size (adult vs pediatric). These findings support more accurate patient positioning and protocol optimization for PCCT to improve dose efficiency and image quality, especially in children.

Klüner LV, Haubold J, Peuster H et al. · Investigative radiology · (2026) · 2 citations · 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 parameter 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’), the study identified an optimal combination of SPCCT reconstruction kernel (STD-B or HRB) and iDose4 level (i5/i7/i9/i11) that improved detectability of peritoneal metastases relative to the reference EID-DECT reconstruction. This provides actionable reconstruction guidance to enhance peritoneal metastasis detection with SPCCT, potentially improving staging and treatment planning.

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

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PCCT/SPCCT vs Energy-Integrating CT (Comparative Performance)

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 whether PCD-CT improves diagnostic image quality while reducing CT dose metrics such as CTDIvol. Clinically, the results inform whether PCD-CT can enable safer, higher-quality CT surveillance of MM-related bone disease within existing imaging pathways.

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

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Energy-Resolved Imaging & Virtual Monoenergetic/Virtual Non-Contrast Techniques

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 the assessability of lower extremity arteries in (poly-)trauma patients using a double-bolus contrast protocol. The key finding was that certain VME energy levels provided sufficient vascular contrast (defined as >200 Hounsfield Units) and improved evaluation of peripheral arteries in extended trauma scans. This is clinically significant because it helps optimize energy-resolved reconstructions to improve detection of vascular pathology in trauma without additional scanning.

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 evaluated 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 myeloma assessment using PCD-CT must account for VMI energy to ensure accurate and reproducible thresholding.

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

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Radiomics & AI for Spectral/Photon-Counting CT Biomarkers

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

This review evaluated the emerging role of coronary artery calcium (CAC) scoring using opportunistic detection on thoracic CT performed for other indications (e.g., lung cancer screening, routine thoracic CT, and attenuation-correction CT). The key finding is that identifying CAC on existing thoracic CT scans can improve cardiovascular risk assessment and guide preventive therapy, despite the current lack of randomized trials proving outcome benefit. The scientific significance is that AI/ML-enabled CAC detection could expand preventive cardiology within routine radiology workflows, pending stronger clinical evidence.

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

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

This multicenter study assessed whether radiomics-based machine learning using spectral reconstructions from contrast-enhanced photon-counting detector CT (PCD-CT) can classify focal liver lesions as benign versus malignant. Using multispectral virtual monochromatic images and material decomposition images, with automatic lesion segmentation via a nnU-Net model, the study evaluated diagnostic performance across two institutions. The clinical significance is that PCD-CT spectral radiomics may improve noninvasive liver lesion characterization beyond conventional CT, potentially reducing the need for invasive diagnostic procedures.

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 whether PCCT-derived abdominal body composition parameters are associated with metabolic abnormality clustering and developed clinical, imaging, and combined prediction models. The key finding was that abdominal body composition metrics derived from PCCT improved prediction of metabolic abnormality clustering, and the internally validated models (clinical, imaging, and combined) supported risk stratification beyond clinical factors alone. Clinically, this suggests PCCT body-composition biomarkers could help identify patients at higher metabolic risk using routine abdominal imaging.

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

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Coronary CT Angiography, Plaque, and Functional Assessment

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, where midventricular takotsubo cardiomyopathy was evaluated using photon-counting detector coronary CT angiography (PCD-CCTA). The key finding was that PCD-CCTA provided a comprehensive assessment that excluded obstructive coronary artery disease and, with multiphase cine reconstructions, characterized the midventricular wall-motion abnormality pattern consistent with takotsubo. The clinical significance is that photon-counting coronary CT can support rapid, noninvasive differentiation of takotsubo cardiomyopathy from acute coronary syndromes.

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 article assessed emerging quantitative cardiac CT approaches for coronary artery disease (CAD), focusing on integrating stenosis quantification, plaque quantification, and fractional flow reserve derived from CT (FFR-CT) using cardiac CT angiography (CCTA) and AI-based quantitative imaging. The key finding is that AI-driven quantitative CT can reduce interobserver variability and improve reproducibility by extracting plaque biomarkers and stenosis metrics that better support risk stratification than stenosis-only assessment. Scientifically and clinically, this framework supports more efficient CAD evaluation and more individualized management decisions using CT-derived anatomical and physiological information.

Mihalcioiu S, Mengesha B, Abitbol C et al. · The British journal of radiology · (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 assessed whether combining ultrahigh-resolution (UHR) photon-counting detector CT angiography (PCD-CTA) with 3D volume rendering (3DVR) yields reliable morphologic assessment and reproducible size measurements for preoperative intracranial aneurysm evaluation. In 21 patients with 32 aneurysms, two neurosurgeons evaluated 2D UHR and 3DVR datasets for image quality and aneurysm characterization, with the combined approach demonstrating feasibility and reproducibility for aneurysm size measurement. The clinical significance is that UHR PCD-CTA plus 3DVR could improve preoperative planning by providing more detailed and consistent aneurysm visualization than conventional 2D assessment.

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

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CT-Guided PCI Planning and Workflow Integration

CT-guided PCI: From diagnosis to treatment planning.

This review described CT-guided percutaneous coronary intervention (CT-guided PCI) as an extension of coronary CT angiography (CCTA) from diagnosis to procedural planning by integrating morphological and physiological lesion information. The key finding is that advances in CT-derived myocardial mass quantification, CT-based physiology, and 3D co-registration can improve individualized revascularization planning before PCI, with photon-counting CT proposed to further refine accuracy. Scientifically, this supports a workflow shift toward more data-driven, patient-specific PCI planning using CT-derived anatomical and functional metrics.

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

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High-Risk Plaque in Acute Coronary Syndromes

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

This review article summarizes evidence on the diagnostic and prognostic value of coronary computed tomography angiography (CCTA) and high-risk plaque assessment in patients presenting with acute coronary syndrome (ACS). The key finding is that beyond detecting coronary stenosis, CCTA can characterize plaque composition and identify high-risk plaque features that may help risk stratification and guide selection for invasive coronary angiography. Clinically, it supports integrating energy-resolved/advanced CCTA plaque assessment into ACS pathways to improve prognostic assessment and potentially reduce unnecessary invasive procedures.

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

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Radiation Dose Reduction in Specialized CT Protocols

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 radiation dose between photon-counting detector CT myelography (PCD-CTM) and 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 lowered session dose-length product (DLP) for the entire CT myelography examination compared with EID-CTM. Clinically, this dose reduction could make repeated SIH evaluations safer while maintaining the diagnostic goal of identifying 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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Dynamic/Functional Imaging with Photon-Counting CT (Airway and Other)

Advanced Imaging to Assess Airway Dynamics.

This narrative review summarized imaging methods for pediatric dynamic airway assessment, contrasting endoscopy with noninvasive techniques including four-dimensional CT and photon-counting CT, as well as MRI-based dynamic cine approaches. The key finding is that 4D CT enables objective quantification of tracheal collapse during free breathing, while photon-counting CT can achieve substantially lower effective doses suitable for serial monitoring, and MRI provides radiation-free dynamic assessment with high spatial detail. These advances are significant for improving diagnosis and longitudinal follow-up of dynamic airway disorders while minimizing procedural invasiveness and radiation exposure.

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

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Oncology Imaging with Photon-Counting CT (Staging, Detection, Response)

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

This 2026 narrative review summarized how coronary CT angiography (CCTA) is used for diagnosis, prognosis, and percutaneous coronary intervention (PCI) planning in patients with coronary artery disease. It found that CCTA’s prognostic value is driven more by overall atherosclerotic burden and plaque morphology (e.g., high-risk plaque and pericoronary fat) than by stenosis severity alone, leading to updates such as revisions to CAD-RADS classification. Scientifically and clinically, the review supports using CCTA not only to detect disease but also to guide risk assessment and PCI planning using plaque and functional information (including CT-derived fractional flow reserve).

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

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Liver Imaging & Hepatic Quantification (Steatosis, Lesions, HCC 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 meaningfully affected image noise and signal-to-noise, thereby changing the conspicuity/assessability of residual viable tumor on follow-up PCD-CT. These results support optimizing PCD-CT reconstruction parameters to improve post-TACE response assessment and potentially reduce missed residual disease in HCC follow-up.

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

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) liver CT for hepatic steatosis quantification, using 49 patients with abdominal PCD-CT and MRI-proton density fat fraction (PDFF). The key finding was that 190-keV VMI showed strong attenuation agreement with TNC (and was compared against virtual non-contrast, VNC) for segmental liver measurements used in steatosis assessment. Scientifically and clinically, this supports using energy-resolved PCD-CT reconstructions to approximate non-contrast attenuation without requiring a separate true non-contrast scan, potentially simplifying steatosis workflows.

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

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Musculoskeletal & Orthopedic Imaging (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 postoperatively. Bone ingrowth (osseointegration) increased across most peri-implant zones over 12 months, while cortical thickness/density and zone-based osteolysis assessments were used to characterize remodeling. These findings support PCD-CT as a quantitative imaging tool for monitoring implant integration and early 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) with energy-integrating detector CT (EID-CT), iterative metal artifact reduction (iMAR), and virtual monoenergetic imaging (VMI) 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 with spectral reconstructions (including tin filtration) and iMAR/VMIs can reduce metal artifacts and improve quantitative/qualitative image performance relative to conventional EID approaches. Scientifically and clinically, improved artifact control in postoperative spine hardware imaging can enhance assessment of adjacent structures and hardware-related complications.

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

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

This narrative review summarizes emerging evidence on photon-counting detector CT (PCD-CT) for temporal bone imaging and specifically addresses whether higher spatial resolution translates into meaningful clinical decision-making. The key finding across the reviewed literature was that PCD-CT’s improved spatial resolution and noise characteristics are promising for submillimeter temporal bone structures, but the clinical impact depends on how these technical gains affect diagnostic performance and outcomes. Scientifically, the review frames where future studies should focus (e.g., lesion detectability, measurement reliability, and dose/benefit tradeoffs) to justify routine adoption of higher-resolution PCD-CT in otologic imaging.

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 tin-filtration photon-counting CT (PCD-CT) in patients with suspected or confirmed temporal bone lesions, comparing it with prior conventional energy-integrating CT (EID-CT). The key finding was that PCD-CT reconstructed at 0.2 mm (PCD-0.2) and 0.6 mm (PCD-0.6) slice thicknesses could reduce radiation dose while maintaining or improving image quality for temporal bone assessment relative to EID-CT. The clinical significance is that photon-counting CT may enable safer, higher-detail temporal bone imaging with lower patient exposure.

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

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Other Clinical Applications (e.g., Parathyroid, Myelography, Devices)

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) versus the smallest commercial i-gel size 1.0 in stillborn low-birth-weight neonates (>500 g) using photon-counting CT to evaluate anatomical positioning. 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 tested prototype sizes. Clinically, this imaging-based evaluation can guide selection/design of neonatal airway devices to improve safety for resuscitation and surfactant administration 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 compared photon-counting CT (PCCT) with energy-integrating detector CT (EIDCT) for 4D parathyroid imaging, focusing on radiation output (CTDIvol and DLP) and image quality (SNR and contrast-to-noise ratio). The key finding was that PCCT can improve dose efficiency and/or image quality in the context of repeated multiphase acquisitions typical of parathyroid 4DCT. The clinical significance is that PCCT may enable more reliable parathyroid localization while reducing cumulative radiation exposure in patients undergoing 4D imaging.

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

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Generated automatically on October 03, 2026. Covers PubMed articles published September 26, 2026 – October 03, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.