What’s New in Photon Counting CT?

July 03, 2026 · 25 articles · 15 research themes · covering June 26, 2026 – July 03, 2026

Overview

Across this week’s set of studies and reviews, photon-counting detector CT (PCD-CT) is repeatedly positioned as a step-change in “spectral + quantitative” imaging: spectral decomposition, virtual monoenergetic imaging, and material/iodine quantification are being translated into practical diagnostic tasks. Foundational work (including physics limits for proton stopping power/range estimation and broader cardiovascular imaging reviews) emphasizes that PCD-CT’s multi-energy information can improve characterization—while also highlighting that adoption depends on overcoming constraints such as protocol standardization, reconstruction tradeoffs, and real-world implementation barriers.

Clinically, the dominant application threads are cardiovascular and neurovascular imaging. For coronary disease, multiple papers focus on making PCD-CT reliable for routine decision-making: optimizing iodine delivery for coronary CTA, improving CAC scoring reproducibility via acquisition/threshold strategies, and synthesizing evidence on CCTA versus invasive angiography (including how emerging PCD-CT concepts may shift the noninvasive–invasive balance). In neurovascular care, photon-counting CT angiography and myelography studies target diagnostic confidence and follow-up accuracy—using higher spatial resolution, improved artifact handling, and AI-assisted denoising to better visualize challenging anatomy (e.g., intra-aneurysmal flow disruption and CSF–venous fistulas in spontaneous intracranial hypotension).

Outside the core cardiovascular/neurovascular themes, the digest shows PCD-CT moving into oncology and musculoskeletal phenotyping. Spectral/iodine metrics are explored as noninvasive biomarkers (e.g., predicting PD-L1 expression in NSCLC), while breast and thoracic oncology reviews argue that improved resolution and spectral capabilities could refine staging and response assessment. In musculoskeletal imaging, spectral CT approaches are evaluated for distinguishing crystal types driving osteoarthritis inflammation, and CT is reinforced as a valuable tool for OA research and biomechanics. Finally, several studies address the practical “how”: dose optimization using phantom/Monte Carlo methods, workflow impacts (e.g., follow-up recommendation rates), and strategies to mitigate metal/implant-related artifacts—collectively pointing toward PCD-CT becoming not just a new scanner technology, but an integrated imaging platform with tunable performance for specific clinical questions.

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Photon-Counting CT (PCD-CT) Spectral Physics & Quantitative Methods

Orbital Imaging Modalities and Recent Updates.

This review article surveyed orbital imaging modalities and recent updates, emphasizing how cone-beam CT and photon-counting CT may add value alongside ultrasound, CT, MRI, and PET. It concluded that different modalities provide complementary strengths—US for superficial structures, CT for bone assessment, MRI for tissue characterization, and PET for biochemical/metabolic information—while photon-counting CT offers emerging potential for improved orbital imaging. The significance is guiding modality selection for complex orbital anatomy by integrating new CT technologies into clinical practice.

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

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

This narrative review synthesized evidence from PubMed, Web of Science, and Embase (2015–March 2025) on photon-counting detector CT (PCD-CT) for cardiovascular imaging, covering technical advances, clinical applications, limitations, and future directions. The key finding was that PCD-CT’s spectral capabilities (photon counting and material/spectral CT approaches) enable improved characterization relevant to coronary artery disease and congenital heart disease, while current limitations include practical constraints that affect broader adoption. Scientifically and clinically, the review frames where PCD-CT may improve diagnostic performance and workflow in cardiovascular imaging and highlights research priorities to overcome remaining barriers.

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

Optimal dimensionality and fundamental limits of proton stopping power estimation with photon-counting CT material decomposition.

This physics study investigated the optimal dimensionality and fundamental limits of proton stopping power ratio (SPR) and range estimation using photon-counting CT (PCCT) with material decomposition (MD), using Eigentissue decomposition as the framework. The key finding was that increasing the number of energy measurements and exploring higher-dimensional MD formulations can improve SPR/range estimation accuracy, but there are fundamental constraints that bound achievable performance for proton therapy planning. Scientifically, these results define how PCCT spectral information and MD dimensionality should be optimized to reduce range uncertainty and treatment margins in proton therapy.

Larsson K, Näsmark T, Andersson J et al. · Physics in medicine and biology · (2026) · View on PubMed ↗ · Free PDF ↗

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Coronary CT Angiography (CCTA) with PCD-CT: Contrast, Protocols, and Workflow

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

This comparative review studied coronary CT angiography (CCTA) versus invasive coronary angiography (ICA) by synthesizing diagnostic performance, clinical outcomes, and technical principles from literature published between 2015 and March 2026, including emerging photon-counting detector CT (PCD-CT) concepts. It found that CCTA is increasingly central for noninvasive risk stratification, while ICA remains important for specific scenarios where CCTA limitations (e.g., physical/technical constraints) apply. The review’s significance is to clarify how next-generation CT technologies such as PCD-CT may shift the balance between noninvasive and invasive coronary imaging.

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

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) injection protocol for coronary CT angiography (cCTA) on photon-counting CT, using a 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 range (500±50) using reader-perceived enhancement as an additional assessment. A validated IDR-based protocol could standardize contrast dosing on photon-counting CT to improve coronary enhancement consistency and potentially reduce contrast-related risk.

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 & Thresholding on PCD-CT

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.

Using a chest phantom with nine calcifications, this experimental study assessed how virtual monoenergetic image (VMI) reconstructions (50–80 keV in 5-keV steps) and adjusted coronary artery calcium (CAC) thresholds affect reproducibility of CAC scoring on a photon-counting detector CT protocol. The key finding was that VMI-based threshold adjustment could further reduce CAC score variability beyond the optimized PCD-CT protocol from Part I. Improving CAC score reproducibility is scientifically and clinically important for more reliable cardiovascular risk stratification across scans and sites.

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 study investigated photon-counting detector CT (PCD-CT) coronary artery calcium (CAC) scoring variability and aimed to propose a protocol with decreased variability by varying 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). The key finding was that specific combinations of acquisition parameters and quantum IR levels meaningfully influenced interscan variability of CAC scores in the phantom. Establishing a lower-variability PCD-CT CAC protocol supports more consistent cardiovascular risk assessment when using photon-counting technology.

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 on PCD-CT

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

In a post hoc analysis of a prospective cohort, this study evaluated spectral ultrahigh-resolution photon-counting CT angiography for below-knee peripheral artery disease (PAD) by testing how extremity-specific isotropic voxel spacing affects image quality and diagnostic performance. The key finding was the impact of isotropic voxel spacing on performance metrics for spectral UHR PCD-CT lower-limb CTA reconstructed from a dual-source PCD-CT system in spectral-UHR mode (120×0.2 mm collimation). Optimizing isotropic reconstruction could improve noninvasive PAD assessment and guide selection of reconstruction parameters for clinical spectral PCD-CT angiography.

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

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Neurovascular Imaging: Aneurysms, Myelography, and Cerebrovascular Fistulas

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

This retrospective comparative study evaluated photon-counting detector CT myelography (PCD-CTM) versus energy-integrating detector CT myelography (EID-CTM) for detecting CSF-venous fistulas (CVFs) in 456 patients (628 CTM examinations) with spontaneous intracranial hypotension (SIH). It found that PCD-CTM improved diagnostic certainty for CVF detection using the Duke CSF-Venous Fistula Confidence Score (DCCS) compared with EID-CTM. The clinical significance is that higher spatial resolution from photon-counting CT can increase confidence in identifying CVFs, potentially improving SIH diagnosis and downstream management.

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

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) versus digital subtraction angiography (DSA) and MR angiography for assessing intra-aneurysmal flow disrupting devices (IAFD) in consecutive patients with intracranial aneurysms treated between April 2023 and April 2025. PCD-CTA using polyenergetic imaging with iodine and virtual monoenergetic reconstructions (40 and 80 keV) and different head vessel kernels (Hv56, Hv72), with and without iterative metal artifact reduction, was assessed for post-interventional depiction of intra-aneurysmal flow disruption. If validated, PCD-CTA could provide a more accurate, less invasive alternative to DSA for routine follow-up of IAFD-treated aneurysms, improving post-procedural surveillance and device assessment.

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

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Neurovascular UHR PCD-CTA Reconstruction & AI 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 examined whether deep learning-based post hoc denoising improves image quality and diagnostic confidence in neurovascular ultrahigh-resolution photon-counting CT angiography (UHR PCD-CTA) in 42 patients. It found that adding an artificial intelligence-based denoising (AID) algorithm to vendor iterative reconstruction (level 4) improved image quality and increased diagnostic confidence, particularly in lower-neck and artifact-prone regions. The significance is that AI denoising can help realize the diagnostic potential of UHR photon-counting CT 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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Oncology Imaging with PCD-CT (Thoracic/NSCLC, Breast, and Beyond)

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) 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 as the reference standard for staging conspicuity. If PCD-CT achieves comparable conspicuity, it could support radiation-based staging workflows that may reduce reliance on MRI for breast lesion visualization.

Kawasaki Y, Nakajima M, Yokoyama K et al. · Japanese journal of radiology · (2026) · 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) in thoracic oncology, focusing on how intrinsic spectral imaging and improved spatial resolution/dose–image-quality tradeoffs may change tumor imaging. The key finding was that PCD-CT’s spectral capabilities and higher detail can enable more precise characterization of thoracic tumors and related imaging tasks compared with conventional energy-integrating detector CT. This is significant because it frames how PCD-CT could support improved staging, response assessment, and potentially AI-enabled quantitative imaging in thoracic cancer care.

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

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

This review evaluated 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 was that CCTA provides not only stenosis evaluation but also plaque composition and high-risk plaque features, which may help refine patient selection for invasive coronary angiography and improve risk stratification. If implemented, CCTA-based high-risk plaque assessment could enhance clinical decision-making in ACS by identifying patients most likely to benefit from invasive management.

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

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Immunotherapy Biomarkers from PCD-CT Spectral/Iodine Metrics

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 as the reference standard. It reported that arterial and venous-phase spectral CT values at 40, 70, and 100 keV and lesion iodine concentration (measured from pretherapeutic PCCT) were informative for distinguishing PD-L1 expression categories (TPS <1%, 1–49%, and ≥50%). The clinical significance is that PCCT-derived spectral/iodine metrics could support noninvasive PD-L1 assessment to guide immunotherapy selection in NSCLC.

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

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Hepatobiliary Imaging: Portal Vein Thrombosis Characterization

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) iodine density (ID) quantification to distinguish neoplastic versus bland portal vein thrombosis (PVT) in 104 patients with suspected PVT and underlying hepatocellular carcinoma. The key finding was that quantitative iodine density from PCD-CT improved diagnostic discrimination between bland and neoplastic PVT compared with conventional qualitative imaging criteria. More accurate PVT classification is clinically significant because it directly affects prognosis and management in HCC.

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

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Musculoskeletal Crystal & Osteoarthritis Imaging (DECT/CBCT/SPCCT/CT)

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 enrolled patients scheduled for finger-joint surgery due to osteoarthritis to compare 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. The key finding was the relative diagnostic performance of SPCCT versus DECT/US/CBCT against reference standards of compensated polarized light microscopy of synovial fluid and histology. Demonstrating superior or complementary accuracy for SPCCT would improve noninvasive identification of crystal types that drive osteoarthritis-related inflammatory phenotypes and treatment decisions.

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

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Osteoarthritis CT Research & Biomechanics/Phenotyping

The current state of computed tomography in osteoarthritis research.

This narrative review summarized the current role of computed tomography (CT) in osteoarthritis (OA) research, covering structural features, shape modeling, alignment, contact stress modeling, bone morphometry and bone mineral density, cartilage/meniscus assessment, and multimodal combinations. It highlighted that CT’s high-resolution bone visualization enables accurate quantification of osteophytes, subchondral bone cysts, sclerosis, and joint space width, and supports 3D bone shape modeling for biomechanical analyses. Scientifically, the review positions CT as a complementary 3D tool for OA phenotyping and mechanics research, informing future imaging biomarkers and study designs.

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

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Hearing Loss & Temporal Bone CT Interpretation with PCD-CT

Conductive hearing loss and normal CT: a clinical perspective.

This clinical perspective reviewed literature and provided illustrative cases linking audiology with photon-counting detector CT findings in patients with conductive hearing loss who had normal or non-explanatory temporal bone CT. The key finding was that while conductive hearing loss is often attributable to CT-detectable pathology (e.g., otosclerosis), there are clinical scenarios where no imaging correlate is found, meaning CT is not 100% sensitive for all causes. Clinically, this supports integrating audiologic testing with advanced CT interpretation (including photon-counting CT when available) rather than relying on temporal bone CT alone to explain conductive hearing loss.

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

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Dose Optimization & Radiation Safety in PCD-CT (Phantoms/Monte Carlo/Spectral Shaping)

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

The study investigated spectral shaping for point-of-care extremity photon-counting detector (PCD) CT by estimating organ absorbed dose using Monte Carlo simulations across different source voltage and filtration settings. It found that adjusting CT spectral output can reduce organ absorbed dose compared with conventional CTDI-based optimization while maintaining image quality (as assessed in the simulation framework). This supports patient- and organ-specific dose optimization for photon-counting CT in extremity imaging, improving the scientific basis for safer point-of-care protocols.

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

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

This phantom-based study scanned adult and pediatric head anthropomorphic phantoms on photon-counting CT across multiple image quality levels (IQLs) to characterize how radiation dose relates to signal-to-noise ratio (SNR) for brain parenchyma and bone. The key finding was that radiation dose increased linearly with IQL while SNR followed a non-linear trend, enabling identification of IQL ranges for dose optimization. Defining dose–SNR behavior in pediatric and adult heads is clinically significant for selecting PCCT settings that preserve image quality while minimizing radiation exposure.

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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Abdominal Imaging Workflow: Follow-up Recommendations & Practical Implementation

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

This review article examined practical strategies to maximize the clinical impact of photon-counting CT (PCD-CT) in abdominal imaging, focusing on its spectral/quantitative capabilities and reconstruction flexibility. It concluded that PCD-CT enables retrospective virtual monoenergetic imaging and material decomposition that can be tailored to specific abdominal diagnostic tasks, improving dose efficiency and diagnostic utility beyond morphology-only assessment. Clinically, the work frames how to translate photon-counting detector advantages into actionable imaging workflows for abdominal radiology.

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

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

This retrospective PACS/report review 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. The key finding was the relative frequency of radiology-recommended follow-up imaging across scanner types, excluding studies lacking virtual noncontrast and iodine map images. 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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Artifact Reduction & Implant/Metal Challenges in PCD-CT

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

This study assessed how different iterative metal artifact reduction (IMAR) presets affect image quality and diagnostic performance in ultra-high-resolution photon-counting CT angiography (UHR-PCCTA) for 25 patients (31 lower extremities) with total knee endoprostheses. It found that IMAR settings meaningfully change artifact burden and visualization of the popliteal vasculature, which is otherwise degraded by knee prosthesis metal artifacts. The significance is improved optimization of UHR-PCCTA reconstruction parameters to enable more reliable peripheral artery assessment in patients with knee implants.

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

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

This case report described an 11-year-old elite athlete with ischio-pubic ramus synchondrosis that was initially misinterpreted as a tumor on MRI and was later characterized using virtual non-calcium imaging on a photon-counting CT scanner. It demonstrated that virtual non-calcium imaging can provide low-dose, straightforward interpretation that helps distinguish pseudo-tumor pathology from true neoplasm. The clinical significance is that photon-counting CT virtual non-calcium techniques may reduce diagnostic uncertainty and unnecessary workup in pediatric musculoskeletal “tumor-like” 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 03, 2026. Covers PubMed articles published June 26, 2026 – July 03, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.