What’s New in Photon Counting CT?

July 01, 2026 · 18 articles · 15 research themes · covering June 24, 2026 – July 01, 2026

Overview

Across this week’s set of studies and reviews, photon-counting CT (PCCT) emerges as a platform for both improved physics/quantification and clinically actionable imaging. A major thread is optimization: phantom and protocol work show how acquisition settings (image quality levels, dose, slice thickness, iterative reconstruction) and reconstruction choices (virtual monoenergetic images, threshold tuning, isotropic voxel spacing) can reduce variability and sharpen dose–image-quality trade-offs. Complementing this, contrast-focused research (e.g., personalized iodine delivery rate for coronary CTA and iodine density quantification for portal vein thrombosis subtyping) highlights PCCT’s ability to translate spectral information into more consistent, quantitative biomarkers.

Clinically, the dominant application areas are cardiovascular and angiographic imaging, with multiple studies/reviews emphasizing the value of spectral/energy-selective reconstructions for vascular assessment. In coronary disease, work on coronary enhancement consistency and reproducible coronary artery calcium (CAC) scoring supports more reliable risk stratification, while a review on CCTA and high-risk plaque underscores how plaque characterization can guide invasive decision-making in acute coronary syndrome. For angiography beyond the heart, photon-counting detector CT angiography is evaluated for post-interventional neurovascular device assessment and for below-knee peripheral artery disease, pointing toward safer noninvasive follow-up compared with invasive reference standards.

Outside the vascular domain, the set broadens PCCT’s reach into oncology, functional imaging, and musculoskeletal research. Breast lesion conspicuity using virtual monoenergetic reconstructions is compared against DCE-MRI, and hepatic imaging leverages iodine density to distinguish neoplastic from bland portal vein thrombosis in HCC. Spectral photon-counting CT feasibility studies demonstrate combined ventilation–perfusion imaging using targeted contrast mechanisms (xenon ventilation plus gadolinium with color K-edge imaging). Finally, musculoskeletal papers and reviews show how CT (including advanced spectral approaches) supports osteoarthritis phenotyping and crystal arthropathy identification, while case-based work illustrates practical diagnostic pitfalls where PCCT virtual non-calcium imaging can prevent unnecessary workups.

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Photon-Counting CT (PCCT) Acquisition & Dose Optimization

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 how photon-counting CT (PCCT) image quality levels (IQLs) affect radiation dose metrics and signal-to-noise ratio (SNR) in adult and pediatric head phantoms. 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 trade-offs. This is scientifically and clinically significant because it provides quantitative guidance for selecting PCCT settings to reduce pediatric and adult head radiation dose while maintaining diagnostic image quality.

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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Photon-Counting CT (PCCT) Image Reconstruction & Quantitative 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 study (Part II) investigated whether virtual monoenergetic image (VMI) reconstructions with adjusted calcium scoring thresholds can further reduce variability in coronary artery calcium (CAC) scoring using a photon-counting detector CT protocol. It found that CAC scoring was performed on a chest phantom with nine calcifications using PCD-CT, with VMI levels from 50–80 keV in 5-keV steps and threshold adjustments to maintain density, aiming to reduce interscan variability beyond the Part I protocol. The scientific significance is that energy-selective reconstruction plus threshold optimization may improve reproducibility of CAC scoring, supporting more reliable cardiovascular risk assessment.

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 (Part I) investigated how photon-counting detector CT (PCD-CT) acquisition parameters affect variability of coronary artery calcium (CAC) scoring and proposed a protocol to reduce that variability. It found that PCD-CT CAC scoring variability was tested across tube voltage (90 vs 120 kVp), tube current/dose levels (100% to 25%), slice thickness (3 mm vs 1 mm), and quantum iterative reconstruction levels (IR 1–4) using a chest phantom with nine calcifications. The clinical significance is a more reproducible PCD-CT CAC scoring protocol, which could help standardize cardiovascular risk stratification across scanners and settings.

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

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Contrast Delivery & Iodine Quantification in PCCT

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

This study investigated and validated a personalized iodine delivery rate (IDR)-based injection protocol for coronary CT angiography (cCTA) on photon-counting CT by deriving an IDR formula to achieve a target HU of 500 in 55 keV reconstructions. It found that candidate IDR calculations were implemented and equivalence of coronary enhancement within a predefined HU range (500±50) was assessed across validation groups using injection rates of 3.5 and 5.0 mL/s, supported by reader assessment of perceived enhancement. The clinical significance is more consistent coronary enhancement with photon-counting CT by tailoring contrast delivery to patient/demographic factors, potentially improving diagnostic reliability and reducing contrast variability.

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

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Cardiovascular Imaging with PCCT (Coronary/ACS/Plaque)

Diagnostic and Prognostic Value of Coronary Computed Tomography Angiography and High-Risk Plaque Assessment in Acute Coronary Syndrome.

This review summarized 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 was that beyond detecting coronary stenosis, CCTA can characterize atherosclerotic plaque composition and high-risk plaque features and may help guide patient selection for invasive coronary angiography. This is clinically significant because it supports using CCTA-derived plaque risk stratification to improve ACS management and prognostication.

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

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CT Angiography with Photon-Counting Detectors (Neuro/Peripheral/Other)

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

This post hoc analysis studied spectral ultrahigh-resolution photon-counting detector CT angiography for below-knee peripheral artery disease in patients with peripheral artery disease (PAD), focusing on how extremity-specific isotropic reconstruction voxel spacing affects image quality and diagnostic performance. It found that reconstruction isotropy (via different isotropic voxel spacing strategies) was evaluated for its impact on CTA image quality and performance in a dual-source PCD-CT system using spectral-UHR mode. The clinical significance is that optimizing isotropic reconstruction parameters may unlock the full diagnostic potential of photon-counting CT for noninvasive PAD assessment.

Griggers JI, Todoran TM, Vecsey-Nagy M et al. · Investigative radiology · (2026) · 3 citations · 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 clinical study evaluated photon-counting detector CT angiography (PCD-CTA) against digital subtraction angiography (DSA) and MR angiography in consecutive patients with intracranial aneurysms treated with intra-aneurysmal flow disrupting devices (IAFD) between April 2023 and April 2025. Using polyenergetic reconstructions with iodine and virtual monoenergetic images at 40 and 80 keV, different head vessel kernels (Hv56/Hv72), and iterative metal artifact reduction, the study found that PCD-CTA provided a viable post-interventional assessment of intra-aneurysmal flow disrupting devices compared with reference modalities. This matters because it supports whether PCCT-based angiography can improve noninvasive follow-up of aneurysm device patency/flow while potentially reducing reliance on invasive DSA.

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

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Oncology Applications of PCCT (Breast/Hepatic/Proton Planning)

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 arterial-phase contrast-enhanced photon-counting detector CT (PCD-CT) using 40- and 70-keV virtual monoenergetic images (VMI) for breast lesion conspicuity in 22 women with surgically confirmed primary breast cancer, compared with dynamic contrast-enhanced T1-weighted MRI (DCE-T1WI). It found that lesion conspicuity on 40- and 70-keV VMI from a single PCD-CT acquisition was assessed against DCE-T1WI by three independent readers, aiming to determine diagnostic comparability. The scientific significance is that photon-counting CT may offer an alternative or complementary staging tool with potentially improved conspicuity from energy-selective reconstructions.

Kawasaki Y, Nakajima M, Yokoyama K et al. · Japanese journal of radiology · (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) iodine density (ID) quantification for distinguishing neoplastic versus bland portal vein thrombosis (PVT) in 104 patients with suspected PVT and underlying hepatocellular carcinoma. It found that quantitative iodine density assessment from every contrast-enhanced acquisition was used to determine diagnostic performance for separating neoplastic PVT from bland PVT. The clinical significance is improved prognostic stratification in HCC by enabling more accurate, quantitative imaging differentiation of PVT subtype.

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

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Radiation Oncology Physics: Proton Range/SPR Estimation from PCCT

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

This theoretical/algorithmic study assessed fundamental limits for proton stopping power ratio (SPR) and range estimation from photon-counting CT (PCCT) data using material decomposition, focusing on how dimensionality choices affect accuracy. The key finding was that PCCT’s increased energy measurements can improve SPR/range estimation, and the work evaluated feasibility and limits for higher-dimensional material decomposition approaches for proton treatment planning. This is significant for radiation oncology because more accurate SPR/range estimation can 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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Spectral/Photon-Counting CT for Functional Ventilation–Perfusion

Simultaneous pulmonary ventilation and perfusion imaging using spectral photon counting CT with xenon and gadolinium-based agents in combination with color K-edge imaging.

This animal feasibility study tested simultaneous pulmonary ventilation and perfusion imaging using spectral photon-counting CT (SPCCT) with xenon gas and a gadolinium-based agent combined with color K-edge imaging in five New Zealand white rabbits. The key finding was that color K-edge imaging enabled by SPCCT is feasible for differentiating and quantifying the gadolinium-based agent while xenon wash-in supported ventilation assessment, with phantom work used to validate gadolinium quantification accuracy and cross-contamination. This is significant because it demonstrates a potential pathway toward noninvasive, combined ventilation–perfusion imaging using spectral photon-counting CT with targeted contrast mechanisms.

Robert A, Poletto S, Erhard K et al. · Diagnostic and interventional imaging · (2026) · View on PubMed ↗ · Free PDF ↗

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Musculoskeletal Imaging & Osteoarthritis Structural Assessment

The current state of computed tomography in osteoarthritis research.

This review studied how computed tomography (CT) is used for three-dimensional structural assessment in osteoarthritis (OA) research across multiple imaging domains. It found that CT’s high-resolution bone visualization enables accurate quantification of osteophytes, subchondral bone cysts, sclerosis, and joint space width (JSW), while also supporting 3-D bone shape modeling and dynamic joint mechanics modeling. These CT capabilities improve the scientific characterization of OA phenotypes and can complement other modalities for more mechanistic and structural outcome assessment.

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

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Crystal Arthropathy Imaging (CPP vs Hydroxyapatite)

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 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 scheduled for finger-joint surgery. It found diagnostic performance was assessed using in vivo imaging tests (DECT/US/CBCT) and an ex vivo reference using spectral photon-counting CT (SPCCT) of excised joint material, with reference standards including compensated polarized light microscopy of synovial fluid and histology. The clinical significance is improved, noninvasive identification of crystal types (CPP vs hydroxyapatite) that drive OA-related crystal arthropathies and could guide targeted management.

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

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Pediatric & Rare/Diagnostic Pitfalls in CT Interpretation

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. It found that virtual non-calcium imaging on photon-counting CT provided straightforward, low-dose interpretation that clarified the pseudo-tumor diagnosis. The clinical significance is that photon-counting CT virtual non-calcium imaging can reduce diagnostic uncertainty and unnecessary workup in pediatric musculoskeletal “tumor-like” lesions.

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

Conductive hearing loss and normal CT: a clinical perspective.

This clinical perspective reviewed literature and presented illustrative cases linking conductive hearing loss with temporal bone CT findings, emphasizing scenarios where CT may appear normal. The key finding was that although conductive hearing loss is often associated with attributable temporal bone CT abnormalities (e.g., otosclerosis), there are clinically relevant exceptions where no explanatory imaging finding is present. This is significant for practice because it helps clinicians interpret “normal CT” in conductive hearing loss and underscores the need to integrate audiology and other diagnostic pathways rather than relying on CT alone.

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

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Orbital Imaging & Multimodality Technique Selection

Orbital Imaging Modalities and Recent Updates.

This review studied orbital imaging performance across modalities (US, CT, MRI, PET) and highlighted emerging CT techniques including cone-beam CT and photon-counting CT for the complex anatomy of the orbit. It found that high-resolution MRI best delineates delicate orbital soft-tissue structures, while CT (including advanced photon-counting approaches) is particularly strong for bone assessment and PET adds biochemical/metabolic information. The clinical significance is improved modality selection for accurate orbital diagnosis by matching the imaging technique to the relevant tissue targets and information type.

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

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Diagnostic Imaging Review & Clinical Perspectives (Non-PCCT Specific or Broad)

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

This narrative review synthesized evidence on photon-counting detector CT (PCD-CT) in cardiovascular imaging, covering technical advances, clinical applications, limitations, and future directions. The key finding was that PCD-CT’s spectral capabilities (e.g., improved material discrimination and spectral CT approaches) have expanding roles in coronary artery disease and congenital heart disease imaging, while current limitations and implementation challenges remain. This is significant because it provides an evidence-based roadmap for researchers and clinicians on where PCD-CT may improve cardiovascular diagnosis and what technical hurdles must be addressed.

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

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Clinical Validation/Comparative Effectiveness of PCCT vs Reference Standards

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

This retrospective study compared follow-up imaging recommendation rates after contrast-enhanced abdominopelvic photon-counting CT (PCCT) versus dual-source dual-energy CT (DECT) and single-energy CT (SECT) in outpatient patients 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 evaluating how PCCT compares to conventional DECT and SECT while excluding PCCT/DECT exams lacking virtual noncontrast and iodine map images in PACS. These results are clinically relevant because they suggest whether photon-counting CT can reduce downstream imaging utilization and associated costs without compromising radiology decision-making.

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

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Generated automatically on July 01, 2026. Covers PubMed articles published June 24, 2026 – July 01, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.