What’s New in Photon Counting CT?

July 07, 2026 · 24 articles · 15 research themes · covering June 30, 2026 – July 07, 2026

Overview

Across this week’s set of studies and reviews, a dominant theme is that photon-counting detector CT (PCD-CT/PCCT) is moving beyond “higher resolution” toward quantitative, task-specific imaging enabled by spectral information. Multiple works focus on how reconstruction choices (virtual monoenergetic images, isotropic voxel spacing, metal artifact reduction presets) and acquisition settings can be tuned to optimize dose–image quality performance and improve diagnostic reliability—particularly in challenging anatomy or artifact-prone scenarios (e.g., implants, peripheral vessels, temporal bone). Complementing this, several studies emphasize quantitative biomarkers derived from spectral/iodine metrics, including iodine quantification for portal vein thrombosis characterization and spectral prediction of NSCLC PD-L1 expression, suggesting a pathway toward noninvasive tissue characterization.

Cardiovascular applications also feature prominently, with efforts to standardize and calibrate coronary CT angiography and calcium scoring on photon-counting platforms. Personalized iodine delivery rate protocols aim to achieve consistent enhancement targets, while phantom-based work evaluates how virtual monoenergetic reconstructions and acquisition parameters affect coronary artery calcium (CAC) variability—supporting reproducibility as a prerequisite for broader clinical adoption. In parallel, vascular and neuroimaging studies (e.g., post-interventional aneurysm device monitoring and cerebrospinal fluid–venous fistula detection in spontaneous intracranial hypotension) report improved diagnostic certainty or performance compared with conventional CT approaches, reinforcing the clinical value of higher spatial resolution and spectral capabilities.

Finally, the digest highlights translation and workflow integration: practical abdominal imaging reviews stress retrospective reconstructions (virtual monoenergetic imaging and material decomposition) as a way to leverage PCCT’s quantitative strengths, while follow-up imaging recommendation analyses explore whether these technical advantages reduce downstream uncertainty and imaging utilization. Artificial intelligence (notably denoising) appears as an enabling technology for ultrahigh-resolution CTA, improving diagnostic confidence in noise-limited regions. Together, these papers portray photon-counting CT as an evolving platform—where spectral quantification, optimized reconstruction, and AI-assisted image quality are converging to improve diagnostic accuracy, standardization, and clinical decision-making.

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

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

This study investigated organ absorbed-dose optimization for a point-of-care forearm photon-counting CT (PCD-CT) using spectral shaping, varying source voltage and filtration and estimating organ doses via Monte Carlo simulation. The key finding is that spectral shaping can reduce radiation exposure while maintaining image quality, and that organ absorbed-dose estimation provides a more patient-relevant assessment than CTDI for extremity PCD-CT. This is significant because it supports dose-optimization strategies tailored to specific organs in extremity imaging, potentially improving safety for point-of-care 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 used adult and pediatric anthropomorphic head phantoms scanned on a photon-counting CT (PCCT) system across multiple image quality levels (IQLs) to quantify how radiation dose metrics (mAs, CTDIvol, DLP, and organ doses) relate to signal-to-noise ratio (SNR) in brain parenchyma and bone. The key finding was that while radiation dose increased linearly with IQL, SNR followed a non-linear relationship, enabling identification of IQL ranges that could optimize dose–image-quality performance. Scientifically and for pediatric imaging optimization, the work provides quantitative guidance for selecting PCCT IQL settings to reduce dose without sacrificing diagnostic SNR.

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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Spectral Imaging & Material Decomposition (Iodine/Calcium/Gadolinium, etc.)

A pilot study: dual-contrast arthrography using photon-counting detector computed tomography with gadolinium and iodine contrasts.

This pilot study developed and validated a dual-contrast PCD-CT spectral material decomposition method to simultaneously separate and quantify iodine, gadolinium, and calcium in dual-contrast arthrography. Using a benchtop PCD-CT system with calibration phantoms (including iodine–gadolinium mixtures) and an ex vivo pig-tail specimen, the approach enabled K-edge-based separation and quantification of the three materials across multiple energy bins. Clinically, this could improve CT/MR-compatible arthrography interpretation by providing more specific, quantitative contrast information than conventional CT or standard MR workflows allow.

Deng X, Day J, Masella O et al. · Physics in medicine and biology · (2026) · View on PubMed ↗ · Free PDF ↗

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Virtual Monoenergetic Imaging & Reconstruction Parameter Optimization

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 patients with total knee endoprostheses. In 25 patients (31 lower extremities) undergoing UHR-PCCTA, the key finding was that different IMAR settings meaningfully affected image quality and visualization of the popliteal vasculature in the presence of knee arthroplasty–related metal artifacts. Clinically, optimizing IMAR parameters could improve noninvasive peripheral artery disease assessment when metallic implants would otherwise limit diagnostic confidence.

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

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 study expanded a photon-counting detector CT (PCD-CT) coronary artery calcium (CAC) scoring protocol by testing how virtual monoenergetic image (VMI) reconstructions affect CAC score variability and required threshold adjustments. The key finding was that VMI levels (50–80 keV in 5 keV steps) with adjusted CAC thresholds were assessed to maintain density consistency and potentially further reduce interscan variability beyond the Part I protocol. Scientifically, optimizing VMI and thresholds could improve reproducibility of CAC scoring, supporting more reliable cardiovascular risk stratification.

Fink N, Koetzier LR, Zsarnoczay E et al. · European 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 studied how isotropic voxel spacing affects image quality and diagnostic performance in spectral ultrahigh-resolution photon-counting CT angiography for below-knee peripheral artery disease in a prospective PAD cohort. The key finding was the evaluation of reconstruction conditions (including spectral-UHR mode on a dual-source PCD-CT system with 120×0.2 mm collimation) to determine how isotropic voxel spacing influences performance metrics for lower-limb CTA. If isotropic reconstruction improves vessel visualization and measurement reliability, it could enhance noninvasive PAD assessment and procedural planning.

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

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Photon-Counting CT in Oncology (Thoracic/NSCLC/Oncology Workflows)

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 patients with non-small cell lung cancer (NSCLC). Using immunohistochemistry to classify PD-L1 TPS into negative (<1%), intermediate (1–49%), and high (≥50%) groups, the study measured arterial/venous lesion CT values at 40, 70, and 100 keV and iodine concentration to derive predictive spectral features. The significance is that PCCT-derived quantitative spectral biomarkers could enable noninvasive PD-L1 assessment, potentially supporting treatment selection without repeat tissue sampling.

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

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 whether prone arterial-phase photon-counting detector CT (PCD-CT) using 40-keV and 70-keV virtual monoenergetic images (VMI) provides breast lesion conspicuity comparable to dynamic contrast-enhanced T1-weighted MRI (DCE-T1WI) in 22 women with surgically confirmed primary breast cancer. The key finding was the comparative reader-based assessment of lesion conspicuity across the two VMI energies versus DCE-T1WI. If VMI-based PCD-CT performs similarly, it could support CT-based staging workflows that reduce reliance on MRI for lesion conspicuity.

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

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

This narrative review synthesized evidence up to May 31, 2025 on photon-counting detector CT (PCD-CT) for thoracic oncology, focusing on technical advances such as spatial resolution, dose–image-quality trade-offs, and intrinsic spectral imaging, including how artificial intelligence has been applied. The key finding was that PCD-CT can address limitations of conventional energy-integrating detector CT (EID-CT) by improving precision and detail through spectral and resolution capabilities relevant to tumor imaging. Clinically, the review frames how PCD-CT may improve thoracic tumor characterization and supports translation of PCCT/PCD-CT into oncology workflows.

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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Photon-Counting CT in Cardiology (Coronary, LVH, Calcium Scoring)

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

This comparative review synthesized evidence on coronary CT angiography (CCTA) versus invasive coronary angiography (ICA), including how underlying technical principles—and emerging photon-counting detector CT (PCD-CT)—may affect diagnostic value and clinical outcomes. The key finding is that CCTA increasingly supports noninvasive risk stratification, while ICA remains important in selected scenarios, and the review highlights that detector technology advances like PCD-CT could further improve image quality and diagnostic utility. Clinically, the synthesis helps define where CCTA can replace or reduce ICA and where future PCD-CT improvements may strengthen noninvasive coronary evaluation.

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

Photon-Counting Computed Tomography for Tissue Characterization in Patients With a Left Ventricular Hypertrophic Phenotype.

This study investigated whether photon-counting CT (PCCT) with late iodine enhancement (LIE) and PCCT-derived extracellular volume (ECV) characterizes left ventricular hypertrophy (LVH) as accurately as cardiac magnetic resonance (CMR) across hypertrophic phenotypes in 182 patients (hypertrophic cardiomyopathy, transthyretin amyloid cardiomyopathy, and secondary LVH). The key finding was that PCCT tissue characterization using spectral information and iodine-based metrics was evaluated for overall and phenotype-specific agreement with CMR (with results reported as part of the truncated abstract). Scientifically and clinically, if PCCT matches CMR performance, it could provide a non-MRI alternative for phenotyping LVH and assessing myocardial remodeling.

De Gori C, Aimo A, Occhipinti M et al. · JACC. Cardiovascular imaging · (2026) · 1 citations · View on PubMed ↗

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Photon-Counting CT Angiography & Vascular Imaging (Peripheral/Neuro/CTA)

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

This retrospective clinical study evaluated photon-counting detector CT angiography (PCD-CTA) against digital subtraction angiography (DSA) and MR angiography (MRA) for assessing intra-aneurysmal flow disrupting devices (IAFDs) in consecutive patients with intracranial aneurysms treated with IAFDs between April 2023 and April 2025. The key finding was that PCD-CTA using polyenergetic reconstructions plus iodine and virtual monoenergetic images at 40 and 80 keV, with different head vessel kernels (Hv56/Hv72) and iterative metal artifact reduction, provided an assessment performance that was compared directly with DSA and MRA by independent readers. Scientifically and clinically, the study supports whether PCCT-based angiography can serve as a less invasive post-interventional alternative to DSA for monitoring device-related flow changes.

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

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Contrast Injection Protocols & Quantitative Enhancement Calibration

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

This study developed and validated a personalized iodine delivery rate (IDR)-based injection protocol for coronary CT angiography on photon-counting CT by calculating an ideal IDR (IDRIDEAL) targeting a 500 HU goal in 55 keV reconstructions and then deriving an IDR formula using demographic predictors. The key finding was that, in validation groups using injection rates of 3.5 and 5.0 mL/s, coronary enhancement could be matched within a predefined HU equivalence range (500 ± 50), with a reader study assessing perceived enhancement. This is clinically significant because it aims to standardize and optimize contrast delivery for consistent coronary enhancement while leveraging photon-counting CT’s spectral/quantitative capabilities.

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

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Diagnostic Performance for Specific Non-Oncologic Diseases (e.g., PVT, CVFs, Crystal Arthropathies)

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 cerebrospinal fluid–venous fistulas (CVFs) in spontaneous intracranial hypotension (SIH). Across 628 CTM examinations in 456 SIH patients (scored with the Duke CSF-Venous Fistula Confidence Score by two neuroradiologists), PCD-CTM improved diagnostic certainty for CVF detection compared with EID-CTM. The significance is that higher-resolution PCD-CTM may increase confidence in identifying CVFs, potentially improving diagnostic accuracy and downstream management of SIH.

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

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 cross-sectional diagnostic test study evaluated 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 osteoarthritic hand joints in patients scheduled for finger-joint surgery. The key finding was the comparative diagnostic performance of these in vivo imaging tests against reference standards using compensated polarized light microscopy of synovial fluid and histology, with SPCCT performed ex vivo on excised material. Clinically, improved detection of CPP/hydroxyapatite could refine diagnosis of crystal arthropathies and guide management in hand osteoarthritis.

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

Photon-counting detector CT with iodine quantification: improved distinction between bland and neoplastic portal vein thrombosis.

This retrospective single-center study evaluated photon-counting detector CT (PCD-CT) with iodine quantification to distinguish neoplastic versus bland portal vein thrombosis (PVT) in 104 patients with suspected PVT. The key finding was that quantitative iodine density (ID) measured in every contrast-enhanced acquisition improved diagnostic discrimination between neoplastic and bland PVT compared with conventional qualitative criteria (as assessed using follow-up data and multidisciplinary consensus). Clinically, better PVT classification in hepatocellular carcinoma can improve prognostication and treatment planning.

Müller L, Jorg T, Grunz JP et al. · European radiology · (2026) · View on PubMed ↗ · Free PDF ↗

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Artificial Intelligence for Photon-Counting CT (Denoising/Workflow Enhancements)

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 assessed how deep learning-based denoising affects image quality and diagnostic confidence in neurovascular ultrahigh-resolution photon-counting CT angiography (UHR PCD-CTA). In 42 patients undergoing clinically indicated head and neck UHR PCD-CTA reconstructed with vendor iterative reconstruction (level 4) with and without additional post hoc AI denoising, the key finding was that the denoising algorithm improved image quality metrics and increased diagnostic confidence, particularly in lower-neck and artifact-prone regions where noise is limiting. Scientifically and clinically, it supports using AI denoising to unlock the diagnostic potential of UHR PCD-CTA by mitigating noise-related limitations.

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

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Clinical Translation, Workflow Integration & Follow-up Decision-Making

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

This practical review assessed strategies to maximize the clinical impact of photon-counting CT (PCD-CT) in abdominal imaging, emphasizing how its spectral and quantitative capabilities can be leveraged beyond morphology. The key finding is that PCD-CT enables flexible retrospective reconstructions—such as virtual monoenergetic imaging and material decomposition—that can be tailored to specific abdominal tasks, potentially improving diagnostic performance and workflow efficiency. Scientifically and clinically, it positions PCD-CT as a shift from purely structural assessment to task-specific quantitative imaging, with the main challenge being translating technical advantages into consistent clinical benefits.

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 outpatient contrast-enhanced abdominopelvic photon-counting CT (PCCT) versus conventional dual-energy CT (dual-source DECT) and single-energy CT (SECT) in adult outpatients scanned between 4/11/2022 and 10/14/2024. The key finding was that follow-up recommendation rates differed across scanner types, with the study assessing the relative frequency and reasons for recommended additional imaging after PCCT compared with DECT and SECT. Clinically, these results inform whether PCCT’s image-quality and spectral capabilities translate into fewer (or more targeted) downstream imaging recommendations and potential cost savings.

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

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Temporal Bone & Other Specialized Anatomy

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

This review evaluated emerging clinical and technical evidence for photon-counting detector CT (PCD-CT) in temporal bone imaging, focusing on whether submillimeter spatial resolution improvements over energy-integrating detector CT (EID-CT) translate into measurable clinical benefits. The key finding is that temporal bone is an ideal test bed for PCD-CT because many target structures are submillimeter, but the review emphasizes that definitive clinical outcome advantages from higher resolution remain incompletely established across the current literature. Scientifically, it frames how PCD-CT’s improved spatial resolution, lower noise, and dose efficiency may enable better visualization of fine temporal bone anatomy, while clinically it highlights the need for outcome-driven studies to justify routine adoption.

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

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Orbital Imaging Pathways & Multimodality Integration

Orbital Imaging Modalities and Recent Updates.

This review studied orbital imaging approaches in patients and described how different modalities visualize the orbit’s bony walls, globe, lacrimal apparatus, soft tissues, optic nerve, and cranial nerves III–VI. It found that high-resolution MRI provides detailed tissue characterization, while emerging cone-beam CT and photon-counting CT can add incremental value, with ultrasound best for superficial structures, CT for bone assessment, and PET for biochemical/metabolic information. These modality-specific strengths support more tailored orbital diagnostic pathways, especially when photon-counting CT or cone-beam CT can improve visualization beyond conventional CT/MRI.

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

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Orthopedic Imaging & Osteoarthritis/Arthrography

The current state of computed tomography in osteoarthritis research.

This review summarized the current state of computed tomography (CT) methods in osteoarthritis (OA) research, focusing on how CT enables three-dimensional structural and biomechanical assessment. The key finding is that CT’s high-resolution bone visualization supports quantitative measurement of osteophytes, subchondral bone cysts, sclerosis, and joint space width (JSW), and it enables 3D bone shape modeling and dynamic evaluation of joint mechanics when combined with other approaches. The significance is that CT provides a powerful, geometry-faithful platform for OA phenotyping and mechanistic studies, complementing other imaging modalities and informing research into disease progression and treatment effects.

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

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Reproducibility & Standardization of Quantitative CT Metrics (e.g., CAC)

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 study investigated how acquisition parameters influence reproducibility of photon-counting detector CT (PCD-CT) coronary artery calcium (CAC) scoring and proposed a protocol to reduce variability. Using a chest phantom with nine calcifications, it varied tube voltage (90 vs 120 kVp), tube current (100% to 25% dose), slice thickness (3 mm vs 1 mm), and quantum iterative reconstruction (IR 1–4) to quantify interscan variability. The clinical significance is that a more reproducible PCD-CT CAC protocol could strengthen CAC as a standardized risk assessment tool.

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

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Pediatric & Case-Based Clinical Utility

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

This case report studied an 11-year-old elite athlete with ischio-pubic ramus synchondrosis that was initially misinterpreted as a tumor on MRI. The key finding was that virtual non-calcium imaging on photon-counting CT enabled straightforward, low-dose interpretation that clarified the benign synchondrosis rather than a neoplasm. Clinically, this supports using virtual non-calcium photon-counting CT to reduce diagnostic uncertainty and unnecessary concern in pediatric pseudo-tumor presentations.

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 07, 2026. Covers PubMed articles published June 30, 2026 – July 07, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.