What’s New in Photon Counting CT?

July 06, 2026 · 23 articles · 15 research themes · covering June 29, 2026 – July 06, 2026

Overview

Across these studies and reviews, photon-counting detector CT (PCD-CT/PCCT) is consistently positioned as a “spectral and quantitative upgrade” to conventional CT—improving material discrimination (e.g., iodine, calcium/non-calcium), enabling virtual monoenergetic reconstructions, and supporting retrospective image generation (virtual noncontrast, iodine maps, material decomposition). This theme runs through cardiovascular applications (coronary enhancement, CAC scoring reproducibility), neurovascular imaging (flow disruption assessment after aneurysm treatment, CSF-venous fistula detection in intracranial hypotension), and broader clinical workflows (abdominal imaging interpretation and follow-up recommendations).

A second dominant thread is protocol optimization to make spectral CT practical and reliable. Multiple phantom and clinical works target reproducibility and robustness: CAC scoring variability is addressed by tuning acquisition parameters and VMI thresholding; PAD/CTA image quality is improved via isotropic voxel spacing selection and iterative metal artifact reduction; and neurovascular UHR-CTA diagnostic confidence is enhanced with deep-learning denoising. In parallel, dose–quality balancing is explicitly modeled, including organ-dose estimation with Monte Carlo methods and pediatric head dose–SNR relationships—reflecting a push toward safer, task-tailored PCD-CT protocols.

Finally, the digest highlights emerging “spectral biomarkers” and diagnostic specificity gains. Quantitative spectral parameters are explored for noninvasive PD-L1 stratification in NSCLC, while thoracic oncology and breast cancer studies evaluate whether PCD-CT can match or complement established imaging (e.g., DCE-MRI). In non-oncologic domains, PCD-CT’s iodine density aims to distinguish neoplastic from bland portal vein thrombosis, and crystal arthropathy imaging compares multi-energy CT/US approaches against microscopy/histology. Together, these results suggest PCD-CT is moving beyond detection toward characterization—using physics-driven quantitative features to guide prognosis, treatment selection, and downstream management.

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Photon-Counting CT (PCD/PCCT) Cardiovascular Imaging

Comparative review of coronary CT angiography versus conventional catheter angiography: diagnostic value, clinical outcomes, and underlying technical principles.

This comparative review studied the diagnostic value and clinical outcomes of coronary CT angiography (CCTA) versus invasive coronary angiography (ICA), synthesizing technical principles and limitations across the literature (2015–March 2026). It emphasizes that emerging photon-counting detector CT (PCD-CT) may address some CCTA constraints by improving spectral/quantitative information and image quality. The significance is a clearer evidence-based framework for selecting CCTA or ICA in modern coronary artery disease pathways, including how next-generation PCD-CT could shift performance boundaries.

Masri S, Sezdi M · Expert review of medical devices · (2026) · View on PubMed ↗

Conductive hearing loss and normal CT: a clinical perspective.

This clinical perspective reviewed literature cases of patients with conductive hearing loss in whom temporal bone CT showed no explanatory findings, and illustrated scenarios using photon-counting detector CT. The key finding is that while conductive hearing loss is often associated with CT-detectable pathology (e.g., otosclerosis), imaging can be falsely negative and some pathophysiologic conditions may not be visualized reliably on CT. Clinically, the article emphasizes integrating audiology with advanced CT approaches (including photon-counting CT) and considering non-CT-visible etiologies when CT is normal.

Rao D, Raymond MJ, Breen JT et al. · Neuroradiology · (2026) · View on PubMed ↗

Photon-counting detector CT in cardiovascular imaging: technical advances, clinical applications, and future perspectives.

This 2026 review synthesized evidence on photon-counting detector CT (PCD-CT) for cardiovascular imaging, focusing on technical advances, clinical applications, limitations, and future directions across conditions such as coronary artery disease and congenital heart disease. The review’s central conclusion is that PCD-CT’s spectral capabilities and improved material discrimination enable broader cardiovascular applications, but performance constraints and practical limitations remain before widespread adoption. Scientifically and clinically, it provides an evidence-based roadmap for researchers and imagers to optimize PCD-CT protocols and to target remaining gaps in cardiovascular diagnostic accuracy.

Hong Z, Yao B, Wu H · The international journal of cardiovascular imaging · (2026) · View on PubMed ↗

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Coronary CT Angiography (CCTA) Protocols & Contrast Optimization

A personalized iodine delivery rate-based injection protocol in coronary angiography on photon-counting CT.

This study proposed and validated a personalized iodine delivery rate (IDR)-based injection protocol for coronary CT angiography (cCTA) on photon-counting CT, using an HU target of 500 in 55-keV reconstructions to derive an IDR formula from demographic predictors. In two validation groups with different injection rates (3.5 and 5.0 mL/s), coronary enhancement was quantified and tested for equivalence within a predefined HU window (500±50), with a reader study evaluating perceived coronary enhancement. A validated IDR protocol could standardize contrast delivery on photon-counting CT, improving coronary enhancement consistency while potentially reducing contrast volume and scan variability.

Busselot T, Giordano P, Sneyers V et al. · European radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Coronary Artery Calcium (CAC) Scoring Reproducibility

Coronary artery calcium scoring: expanding the new standard by photon-counting detector CT Part II: Impact of virtual monoenergetic image reconstructions with adjusted calcium scoring thresholds.

This phantom-based Part II study expanded a photon-counting detector CT (PCD-CT) protocol for coronary artery calcium (CAC) scoring by testing whether virtual monoenergetic image (VMI) reconstructions with adjusted calcium thresholds reduce score variability. Using a chest phantom with nine calcifications scanned with an optimized PCD-CT protocol (120 kVp, 75% dose, thin slices, quantum iterative reconstruction), CAC scoring was performed across VMI levels (50–80 keV) with threshold adjustments to maintain density consistency. If VMI-based thresholding further improves reproducibility, it could strengthen the clinical reliability of PCD-CT CAC scoring for cardiovascular risk stratification.

Fink N, Koetzier LR, Zsarnoczay E et al. · European radiology · (2026) · View on PubMed ↗ · Free PDF ↗

Coronary artery calcium scoring: expanding the new standard by photon-counting detector CT-Part I: Impact of tube voltage, tube current, slice thickness, and quantum iterative reconstructions.

This phantom-based Part I study investigated how photon-counting detector CT (PCD-CT) acquisition parameters affect reproducibility of coronary artery calcium (CAC) scoring and aimed to propose a protocol with reduced variability. A chest phantom containing nine calcifications was scanned on PCD-CT across different tube voltages (90 vs 120 kVp), tube currents (100% to 25% dose), slice thicknesses (3 mm vs 1 mm), and quantum iterative reconstruction levels (IR 1–4) to quantify interscan variability. The resulting protocol optimization is significant because it addresses a key limitation of CAC scoring—limited reproducibility—by tuning PCD-CT settings to improve consistency.

Fink N, Koetzier LR, Zsarnoczay E et al. · European radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Peripheral Artery Disease (PAD) & Lower-Extremity CTA

Comparison of Iterative Metal Artifact Reduction Presets In Ultra-high-resolution Photon-counting CT Angiography of Patients with Total Knee Endoprosthesis.

This study compared iterative metal artifact reduction (IMAR) presets in ultra-high-resolution photon-counting CT angiography (UHR-PCCTA) for 31 lower extremities from 25 patients with total knee endoprosthesis. It assessed how different IMAR settings affected image quality and visualization of the popliteal vasculature despite prosthesis-related metal artifacts. The findings are significant for optimizing UHR-PCCTA reconstruction parameters to improve peripheral artery disease assessment in patients with knee arthroplasty.

Huflage H, Kunz AS, Wech T et al. · Academic radiology · (2026) · View on PubMed ↗ · Free PDF ↗

Spectral Ultrahigh-resolution Photon-counting CT Angiography for Below-knee Peripheral Artery Disease: Impact of Extremity-specific Isotropic Reconstructions.

This post hoc analysis of a prospective cohort evaluated how isotropic voxel spacing affects image quality and diagnostic performance in spectral ultrahigh-resolution (UHR) photon-counting CT angiography for below-knee peripheral artery disease (PAD) in consecutive patients undergoing lower-limb CTA. Using a dual-source PCD-CT system in spectral-UHR mode (120×0.2 mm collimation) with reconstructions at different isotropic voxel spacings, the study assessed performance metrics tied to extremity-specific isotropic reconstruction. Clinically, identifying the optimal isotropic spacing could improve noninvasive visualization of below-knee vasculature and support more accurate PAD assessment with PCD-CT.

Griggers JI, Todoran TM, Vecsey-Nagy M et al. · Investigative radiology · (2026) · 3 citations · View on PubMed ↗

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Vascular/Neurovascular Interventional Follow-up & Flow Assessment

Photon-counting CT-angiography in comparison to digital subtraction angiography and MR-angiography for assessing intra-aneurysmal flow disrupting devices.

This retrospective study evaluated photon-counting detector CT angiography (PCD-CTA) in consecutive patients with intracranial aneurysms treated with intra-aneurysmal flow disrupting devices (IAFD), comparing PCD-CTA against MR angiography and digital subtraction angiography (DSA). PCD-CTA generated polyenergetic and iodine/virtual monoenergetic reconstructions (40 and 80 keV) with different head vessel kernels (Hv56, Hv72), with and without iterative metal artifact reduction, to assess intra-aneurysmal flow disruption. The work supports PCD-CTA as a potentially effective post-interventional imaging alternative for evaluating IAFD-related flow changes when compared with standard DSA and MR angiography.

De Beukelaer F, Wuyts LL, Wiesmann M et al. · Acta neurologica Belgica · (2026) · View on PubMed ↗ · Free PDF ↗

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Intracranial Hypotension & CSF-Venous Fistula Detection

Improved Diagnostic Certainty of Photon-Counting CT Myelography Compared with Energy-Integrating CT for CSF-Venous Fistulas in Spontaneous Intracranial Hypotension.

This retrospective study compared photon-counting detector CT myelography (PCD-CTM) with energy-integrating detector CT myelography (EID-CTM) for detecting CSF-venous fistulas (CVFs) in 456 spontaneous intracranial hypotension (SIH) patients (628 CTM examinations). Using the Duke CSF-Venous Fistula Confidence Score (DCCS) scored by two neuroradiologists with consensus adjudication, PCD-CTM improved CVF detection certainty versus EID-CTM. Clinically, higher diagnostic certainty with PCD-CTM could improve identification of treatable CVFs and thereby support more accurate SIH management.

Christensen SK, Kranz PG, Madhavan AA et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Neurovascular CTA Image Quality & Denoising

Impact of Deep Learning-Based Denoising on Image Quality and Diagnostic Confidence in Neurovascular Ultrahigh-Resolution Photon-Counting CT Angiography.

This retrospective single-center study evaluated the impact of a deep learning-based post hoc denoising (AID) algorithm on image quality and diagnostic confidence in 42 patients undergoing head and neck ultrahigh-resolution photon-counting CT angiography (UHR PCD-CTA). Reconstructions used vendor iterative reconstruction (level 4) with and without additional AI denoising, and the study focused on noise-limited and artifact-prone regions such as the lower neck. The significance is that AI denoising may improve diagnostic confidence in UHR PCD-CTA, potentially enabling lower-dose or more reliable neurovascular imaging.

Tóth A, Hagar MT, Silbergleit M et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Oncology Spectral Imaging & Biomarker Prediction

Quantitative spectral parameters of photon-counting detector CT for noninvasive prediction of PD-L1 expression in non-small cell lung cancer.

This single-center retrospective study evaluated whether quantitative photon-counting CT (PCCT) spectral parameters can noninvasively predict programmed death-ligand 1 (PD-L1) expression in 63 pretherapeutic non-small cell lung cancer (NSCLC) patients. Using immunohistochemistry-defined PD-L1 groups (TPS <1%, 1–49%, ≥50%), the authors measured arterial/venous lesion CT values at 40, 70, and 100 keV and iodine concentration to derive predictive spectral metrics. If validated, these PCCT-derived quantitative parameters could enable noninvasive PD-L1 stratification to guide immunotherapy selection in NSCLC.

Ren J, Fu Z, Li L et al. · BMC medical imaging · (2026) · View on PubMed ↗ · Free PDF ↗

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Breast Cancer Imaging (PCD-CT vs MRI)

Lesion conspicuity assessment of prone 40-keV virtual monoenergetic imaging in arterial-phase photon-counting CT for breast cancer: a retrospective comparison with DCE-MRI.

This retrospective diagnostic feasibility study evaluated prone 40-keV virtual monoenergetic imaging (VMI) derived from arterial-phase photon-counting detector CT (PCD-CT) in 22 women with surgically confirmed primary breast cancer, comparing lesion conspicuity against dynamic contrast-enhanced T1-weighted MRI (DCE-T1WI). Lesion conspicuity on 40-keV PCD-CT VMI was assessed by three independent readers and compared with DCE-T1WI across 40- and 70-keV reconstructions from a single arterial-phase acquisition. If comparable, prone arterial-phase PCD-CT could provide a radiation-based alternative to DCE-MRI for preoperative breast cancer staging with improved lesion visibility using energy-selective reconstruction.

Kawasaki Y, Nakajima M, Yokoyama K et al. · Japanese journal of radiology · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗

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Thoracic Oncology with PCD-CT

Photon-counting detector computed tomography in thoracic oncology: revolutionizing tumor imaging through precision and detail.

This narrative review summarized advances and clinical applications of photon-counting detector CT (PCD-CT) in thoracic oncology, focusing on how intrinsic spectral imaging and improved spatial resolution/dose–quality tradeoffs may enhance tumor imaging. The key contribution was synthesizing evidence from PubMed (through May 31, 2025) on technical developments and practical implications for thoracic cancer imaging workflows. Scientifically and clinically, the review frames how PCD-CT could enable more precise characterization of thoracic tumors and potentially improve staging and treatment response assessment.

Yanagawa M, Ueno M, Ito R et al. · Diagnostic and interventional radiology (Ankara, Turkey) · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗

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Crystal Arthropathies (CPP/HA) Imaging

Accuracy of dual-energy computed tomography (CT), ultrasound, cone-beam CT, and spectral photon-counting CT for detecting calcium crystal deposition in the osteoarthritic hand: a cross-sectional diagnostic test study.

This prospective cross-sectional diagnostic test study assessed dual-energy CT (DECT), ultrasound (US), cone-beam CT (CBCT), and multi-energy spectral photon-counting CT (SPCCT) for detecting calcium pyrophosphate (CPP) and hydroxyapatite crystal deposition in patients with osteoarthritic hand scheduled for finger-joint surgery. The key finding was the relative diagnostic performance of each imaging modality against reference standards of compensated polarized light microscopy of synovial fluid and histology/ex vivo SPCCT of excised joint material. Clinically, identifying which CT/US technique best detects CPP versus hydroxyapatite could improve noninvasive diagnosis and phenotyping of crystal arthropathies.

Døssing A, Stamp LK, Becce F et al. · Scandinavian journal of rheumatology · (2026) · View on PubMed ↗ · Free PDF ↗

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Abdominal Imaging Workflow & Follow-up Recommendations

Seeing the invisible: practical strategies to maximize the clinical impact of photon-counting CT in abdominal imaging.

This article reviewed practical strategies to maximize the clinical impact of photon-counting CT (PCD-CT) in abdominal imaging, focusing on how its spectral and quantitative capabilities change reconstruction and interpretation. It highlights that PCD-CT enables retrospective spectral reconstructions such as virtual monoenergetic imaging and material decomposition, improving dose efficiency and diagnostic utility beyond conventional morphology-only workflows. Clinically, these approaches can translate PCD-CT’s detector physics into more task-tailored abdominal imaging for better diagnostic confidence and potentially improved outcomes.

Yokoyama K, Kawasaki Y, Fujii M et al. · Abdominal radiology (New York) · (2026) · View on PubMed ↗ · Free PDF ↗

Follow-up recommendation rates with abdominopelvic photon counting CT: comparison with conventional dual-energy and single-energy CT.

This retrospective PACS-based study compared follow-up imaging recommendation rates after abdominopelvic photon-counting CT (PCCT) versus conventional dual-energy CT (DECT) and single-energy CT (SECT) in outpatient contrast-enhanced examinations. After excluding PCCT/DECT studies lacking virtual noncontrast and iodine map images, radiology reports were reviewed for whether follow-up imaging was recommended and the stated reasons, and rates were compared across scanner types. If PCCT reduces unnecessary follow-up recommendations, it could lower downstream costs and patient burden while maintaining diagnostic adequacy.

Dane B, Attlassy Y, Ihionkhan E et al. · Abdominal radiology (New York) · (2026) · 1 citations · View on PubMed ↗

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Radiation Dose Optimization & Dose–Quality Modeling

Organ dose optimization for a point-of-care forearm X-ray photon-counting CT.

The study investigated spectral shaping CT dose optimization for an extremity photon-counting detector (PCD) CT by estimating organ absorbed dose using Monte Carlo simulations across different source voltage and filtration settings. Organ-dose estimates showed how spectral shaping can reduce patient radiation exposure compared with CTDI-based assessment while maintaining image quality-relevant performance. This supports more patient-specific, organ-relevant dose optimization for photon-counting extremity CT, improving the scientific basis for safer PCD-CT protocols.

Rodesch PA, Viry A, Khorsi M et al. · Computers in biology and medicine · (2026) · View on PubMed ↗ · Free PDF ↗

Investigating Radiation Dose and Signal-To-Noise-Ratio in Pediatric and Adult Head Photon-Counting CT: A Phantom-Based Study.

This phantom-based study investigated the relationship between radiation dose and signal-to-noise ratio (SNR) in pediatric and adult head photon-counting CT (PCCT) across multiple image quality levels (IQLs). Anthropomorphic phantoms were scanned across IQLs, and dose metrics (mAs, CTDIvol, DLP, organ doses) were correlated with SNR in brain parenchyma and bone, with comparisons performed at matched IQLs. The findings are significant for optimizing PCCT protocols to achieve better dose–image-quality balance, especially in pediatric imaging where dose constraints are critical.

Klüner LV, Opitz MK, Peuster H et al. · RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗

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Musculoskeletal Imaging in Osteoarthritis & Bone Phenotyping

The current state of computed tomography in osteoarthritis research.

This review summarized the current state of computed tomography (CT) in osteoarthritis (OA) research, focusing on how CT supports 3D structural assessment and biomechanical modeling. It highlights CT’s high-resolution bone visualization for quantifying osteophytes, subchondral bone cysts, sclerosis, and joint space width (JSW), as well as enabling 3D bone shape modeling and alignment for contact stress modeling. Scientifically, it positions CT as a key modality for linking structural phenotypes to joint mechanics in OA and for integrating CT with other imaging approaches.

Yoshikawa R, Boddu A, Turmezei TD et al. · JBMR plus · (2026) · View on PubMed ↗ · Free PDF ↗

Orbital Imaging Modalities and Recent Updates.

This case report described a pediatric pseudo-tumor of the ischio-pubic ramus in an 11-year-old elite athlete that was initially misinterpreted as a tumor on MRI. The lesion was correctly characterized using virtual non-calcium imaging on a photon-counting CT scanner, which provided low-dose imaging with straightforward interpretation. The clinical significance is that virtual non-calcium photon-counting CT can reduce diagnostic pitfalls in children by improving specificity for non-calcified/benign bone-related findings.

Martin S · Radiologic clinics of North America · (2026) · View on PubMed ↗

Pediatric pseudo-tumor of the ischio-pubic ramus in virtual non-calcium photon-counting scanner: A case report.

This case report described a pediatric pseudo-tumor of the ischio-pubic ramus (ischio-pubic ramus synchondrosis) in an 11-year-old elite athlete initially misread as a tumor on MRI. It demonstrated that virtual non-calcium imaging on a photon-counting CT scanner can depict the condition with low-dose acquisition and improved interpretability. The significance is practical: photon-counting virtual non-calcium CT may help junior radiologists and clinicians avoid unnecessary workup for benign synchondrosis mimics.

Corelli C, Balligand T, Rodriguez R et al. · Radiology case reports · (2026) · View on PubMed ↗ · Free PDF ↗

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Generated automatically on July 06, 2026. Covers PubMed articles published June 29, 2026 – July 06, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.