What's New in Photon Counting CT? — August 08, 2026
AI-summarised digest of 41 PubMed articles on Photon Counting CT published in the last 7 days.
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What’s New in Photon Counting CT?
August 08, 2026 · 41 articles · 15 research themes · covering August 01, 2026 – August 08, 2026
Overview
Across this week’s papers, photon-counting CT (PCCT) is moving from “promising physics” toward increasingly actionable clinical workflows—especially in angiography. Multiple studies (UHR PCCTA/CCTA, stent and aneurysm follow-up, and peripheral/tibial runoff) show that higher spatial resolution and reduced blooming/artifact limitations can improve visualization of stenosis and post-treatment anatomy compared with conventional energy-integrating CT. Reviews and guidance pieces further consolidate this into protocol decision-making frameworks, while AI is beginning to automate parts of the workflow (e.g., routing CT requests to the right technology and enabling end-to-end differentiable reconstruction).
A second dominant theme is quantitative spectral imaging—using virtual monoenergetic imaging, K-edge approaches, and material decomposition—to extract tissue and biomarker information more robustly than conventional single-energy CT. Work on extracellular volume (ECV) and liver fibrosis demonstrates feasibility of PCCT-derived quantitative biomarkers with agreement against MR elastography and histopathology. In parallel, plaque- and vulnerability-focused studies (including perivascular adipose tissue and low-attenuation plaque detection) highlight how spectral information can mitigate confounders like calcium blooming and improve characterization beyond luminal stenosis.
Finally, the digest emphasizes practical optimization: reconstruction kernels, iterative reconstruction behavior (including “bucket effects”), and energy-threshold selection are shown to materially affect noise, artifacts, and diagnostic quality. Dose and contrast management remain central—phantom and pediatric studies report dose-efficiency gains under matched image quality, and methodological “rule-of-thumb” approaches help preserve contrast-to-noise when tuning VMI energy and contrast dose. Underpinning all of this, physics-focused work clarifies how detector electronics and threshold-bin outputs shape spectral fidelity, reinforcing why system-aware calibration and parameter tuning are essential for reliable clinical translation.
Photon-counting CT (PCCT) physics & signal formation
A physics primer on photon-counting detectors in CT: Physics, signal formation, and performance.
This physics primer reviewed photon-counting detector CT (PCD-CT) signal formation in the detector-readout chain, describing how x-ray interactions generate charge pulses that are processed into threshold-bin count data. It found that threshold-bin outputs are not a direct measurement of photon energy but the end result of coupled physical and electronic steps, which can produce spectral distortion, count loss, and instability depending on operating conditions. This is significant for clinical interpretation and performance evaluation because it provides the mechanistic basis for understanding how PCD-CT spectral data relate to true tissue attenuation.
Chen GH, Lai R, Li K · Medical physics · (2026) · View on PubMed ↗ · Free PDF ↗
Spectral reconstruction & material decomposition (incl. VMI/K-edge)
Comparison of three commercial multi-energy CT and electron density phantoms for iodine quantification and tissue substitute characterization.
This phantom study compared three commercial multi-energy CT and electron density (ED) phantoms for iodine quantification and tissue substitute characterization across diagnostic imaging and radiation therapy contexts. The key finding was that the phantoms differ in how accurately they represent iodine quantification and tissue substitute behavior, affecting performance for both diagnostic and treatment-planning-relevant metrics. This is important for selecting appropriate calibration/validation phantoms when using multi-energy CT or photon-counting CT workflows.
Omar A, Vorbau R, Zimmerman J et al. · Journal of applied clinical medical physics · (2026) · View on PubMed ↗ · Free PDF ↗
K-Edge imaging using a clinical dual-source photon-counting CT system.
This phantom feasibility study evaluated K-edge imaging of iodine (I) and gadolinium (Gd) using a clinical dual-source photon-counting CT system with four energy thresholds (20, 55, 72, 90 keV). The key finding was that K-edge imaging on a clinically available PCCT platform can successfully perform multi-material decomposition for I and Gd using the system’s energy-bin configuration. This is significant because it demonstrates practical clinical translation of K-edge imaging approaches that could reduce dose and motion artifacts in multi-contrast protocols.
Rybertt MV, Liu LP, Sahbaee P et al. · Journal of applied clinical medical physics · (2026) · View on PubMed ↗
Mixed coronary plaque phantom analysis by photon-counting CT: impact of calcium and iodine on low-attenuation plaque detection.
This phantom study compared photon-counting detector CT (PCD-CT) with energy-integrating detector CT (EID-CT) for detecting low-attenuation plaque (LAP) under controlled variations in calcium and iodine content using mixed-plaque inserts and full-rotation helical acquisitions. PCD-CT improved LAP detection relative to EID-CT, with performance influenced by the presence of calcified arcs and iodinated lumen and by reconstruction choices such as virtual monoenergetic imaging (40/70/100/130 keV) and kernel sharpness (Qr40 vs Qr72). The results are scientifically important because they clarify how photon-counting spectral information can mitigate confounding from calcium blooming/attenuation and improve detection of clinically relevant low-attenuation coronary plaque.
Szilveszter B, Kolossváry M, Kubovje A et al. · European heart journal. Imaging methods and practice · (2026) · View on PubMed ↗ · Free PDF ↗
Experimental Evaluation of a Hybrid Iodine-Gadolinium Contrast Medium in Photon-counting Detector CT.
This in vitro study experimentally evaluated a hybrid iodine–gadolinium contrast medium (BAY3685750) for photon-counting detector CT (PCD-CT) by comparing it with conventional iodine-based and gadolinium-based agents in an anthropomorphic abdominal phantom. The key finding was that BAY3685750’s higher effective k-edge behavior and measured relaxivity (r1) supported improved contrast performance in PCD-CT virtual monoenergetic images at higher energies compared with standard iodine formulations. The clinical significance is that high-energy VMI contrast could be enhanced for spectral CT applications where iodine contrast diminishes at elevated energies.
Haag F, Rink J, Lohrke J et al. · Investigative radiology · (2026) · View on PubMed ↗
High-Z Contrast Media for Coronary Photon-counting Detector CT Angiography: Improved Quantification of Calcified Stenoses.
This phantom study evaluated high-Z contrast media for coronary photon-counting detector CT angiography to improve quantification of calcified stenoses, addressing calcium blooming that can overestimate stenosis severity. The key finding was that using contrast media with atomic numbers higher than iodine helps preserve vascular contrast at high VMI energy levels, thereby improving the accuracy of calcified stenosis quantification compared with iodine-based contrast under the same high-energy VMI approach. Clinically, this supports more reliable coronary stenosis assessment in patients with heavy calcification, where conventional CT lumen visualization is limited by blooming artifacts.
Demmert TT, Klambauer K, Schmidt B et al. · Investigative radiology · (2026) · View on PubMed ↗ · Free PDF ↗
Threshold/energy-bin optimization & reconstruction parameter tuning
Small-pixel Acquisition Unmasks “Bucket Effects” of Iterative Reconstruction in Ultra-High-Resolution Photon-Counting CT.
This cadaveric study investigated how small detector pixels (“small pixel effect”) influence signal-to-noise behavior and subjective image quality in ultra-high-resolution photon-counting CT (UHR PCCT) under different iterative reconstruction (IR) kernels. The key finding was that smaller pixels meaningfully unmask “bucket effects” associated with iterative reconstruction, altering both noise characteristics and perceived image quality across dose levels. These results provide practical guidance for optimizing reconstruction settings in UHR PCCT to avoid artifacts and improve diagnostic image quality.
Huflage H, Wech T, Patzer TS et al. · Academic radiology · (2026) · View on PubMed ↗ · Free PDF ↗
Optimizing Photon-counting CT for Congenital Heart Disease: The Value of Ultrasharp Kernels in Neonates and Infants.
This retrospective study evaluated how kernel sharpness (KS) and iterative reconstruction (IR) settings affect high-pitch photon-counting detector CT image quality in neonates and infants with congenital heart disease. Images reconstructed with ultrasharp vascular kernels (varying KS values) and different IR levels showed improved visual image quality ratings compared with less sharp settings, supporting optimized reconstruction for pediatric cardiac PCD-CT. These findings are clinically significant because they provide practical reconstruction parameters to maximize diagnostic image quality while using photon-counting CT in the most dose-sensitive pediatric populations.
Salam B, Sprinkart AM, Hart C et al. · Radiology. Cardiothoracic imaging · (2026) · View on PubMed ↗
Approximate Cramér-Rao lower bound analyses for semi-optimal energy thresholds selection in photon counting CT.
This methodological study developed approximate Cramér–Rao lower bound (CRLB) approaches to select semi-optimal energy thresholds for photon-counting CT without requiring complete system models. Using threshold-scan look-up tables from reference slab phantoms, the proposed linear and nonlinear approximate CRLB methods enabled practical threshold selection aimed at reducing noise in material decomposition. The work is important because it offers a feasible way to tune PCCT spectral separation in real systems where full detector/physics models are unavailable.
Lee O · Medical physics · (2026) · View on PubMed ↗ · Free PDF ↗
AI/Deep learning for PCCT reconstruction & quantitative analysis
End-to-End Differentiable Photon Counting CT.
This engineering study developed an end-to-end differentiable photon-counting CT (differentiable PCCT) framework by making the material decomposition step based on maximum-likelihood estimation (MLE) differentiable via the implicit function theorem and inserting it as a layer into the imaging chain. The key finding was that quantitative spectral information in the image domain can be leveraged for cross-domain learning and upstream optimization by enabling gradient-based training through the full PCCT pipeline. This is significant because it enables new AI/optimization strategies that directly improve quantitative spectral CT performance rather than treating reconstruction and decomposition as separate black boxes.
Wang S, Yang Y, Lee J et al. · IEEE transactions on medical imaging · (2026) · View on PubMed ↗
Fast MRI of bones in the knee - An AI-driven reconstruction approach for adiabatic inversion recovery prepared ultra-short echo time sequences.
This feasibility study investigated an AI-driven reconstruction for accelerating 3D radial inversion recovery ultra-short echo time (IR-UTE) MRI of knee bone using an adiabatic inversion recovery prepared sequence in eight healthy subjects. A supervised denoising convolutional neural network (DnCNN) trained on undersampled data improved reconstruction quality and enabled faster 3D bone imaging compared with conventional approaches. The clinical significance is that it supports radiation-free musculoskeletal bone imaging with reduced scan times, potentially improving patient throughput and tolerance.
Nunn PH, Huflage H, Grunz JP et al. · Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) · (2026) · View on PubMed ↗ · Free PDF ↗
Clinical workflow & protocol guidance for PCCT (cardiac focus)
Automatic Patient Eligibility for Photon-counting CT Using Discriminative and Generative AI Models in Neuroradiology.
This retrospective neuroradiology study evaluated whether NLP-based large language models (LLMs) could automatically route Spanish-language CT requests to photon-counting CT (PCCT) versus conventional energy-integrating detector (EID) CT. The key finding was that discriminative and generative AI approaches can be used to automate PCCT eligibility decisions from free-text CT request information, addressing the lack of neuroradiology-specific guidelines. Automating CT-technology selection could improve workflow efficiency and ensure patients receive PCCT when its spectral/quality advantages are most appropriate.
Martín-Noguerol T, López-Úbeda P, Escartín J et al. · Academic radiology · (2026) · View on PubMed ↗
Comparative review of coronary CT angiography versus conventional catheter angiography: diagnostic value, clinical outcomes, and underlying technical principles.
This narrative review compared coronary CT angiography (CCTA) with invasive coronary angiography (ICA) by synthesizing diagnostic performance, clinical outcomes, and technical principles across literature from 2015 to March 2026. It concluded that CCTA is increasingly central for noninvasive CAD risk stratification and that emerging photon-counting detector CT (PCD-CT) technology may further enhance coronary imaging by improving spectral/contrast capabilities. The significance lies in guiding clinical decision-making and highlighting how next-generation PCD-CT could address limitations of conventional CT in coronary assessment.
Masri S, Sezdi M · Expert review of medical devices · (2026) · View on PubMed ↗
Photon-counting CT in cardiac imaging: multi-institutional guidance on technical principles, clinical evidence, and practical protocols.
This multi-institutional guidance article synthesized technical principles, clinical evidence, and practical protocols for photon-counting CT (PCD-CT) in cardiac imaging, focusing on coronary CT angiography (CCTA) and related applications. It concluded that direct energy discrimination, improved geometric dose efficiency, and ultrahigh spatial resolution can enhance coronary lumen visualization and enable intrinsic spectral imaging compared with energy-integrating CT. The review provides actionable protocol and evidence summaries to support safe and effective clinical implementation of PCD-CT in cardiac workflows.
Hagar MT, Vecsey-Nagy M, Kravchenko D et al. · European journal of radiology · (2026) · 3 citations · View on PubMed ↗
Pictorial review: a step-by-step guide to coronary CT angiography with photon-counting detector CT.
This pictorial review studied how to implement photon-counting detector CT (PCD-CT) coronary CT angiography in clinical practice, focusing on protocol decision-making and scan parameter selection in real-world coronary CT angiogram cases. It reports that PCD-CT can improve coronary plaque component differentiation and spatial resolution while reducing radiation compared with energy-integrating detector CT (EID-CT), and it presents a step-by-step decision-tree workflow for selecting PCD-CT coronary scanning parameters. Clinically, the proposed decision framework aims to standardize and optimize PCD-CT coronary angiography despite limited published experience and variability in current protocols.
Xie C, Clarke N, Kotronias R et al. · The British journal of radiology · (2026) · View on PubMed ↗ · Free PDF ↗
Coronary CT angiography (CCTA) with PCCT/UHR PCCT
Deep Learning-Based Automated Coronary Plaque Quantification with Ultra-high Resolution Photon-Counting Detector CT at Different Spatial Resolutions.
In a prospective single-center study of 70 patients with suspected coronary artery disease undergoing ultra-high-resolution photon-counting CCTA (UHR-CCTA), deep learning was used to automatically quantify coronary stenosis and plaque volumes from reconstructions at 0.6 mm (standard resolution), 0.4 mm (high spatial resolution), and 0.2 mm (ultra-high resolution). The study found that changing spatial resolution affected subjective image quality and the performance of DL-based plaque/stenosis quantification. This supports using ultra-high-resolution PCD-CT reconstructions with DL quantification to improve coronary assessment while balancing resolution-related tradeoffs.
Liu Y, Li R, Zhang H et al. · Academic radiology · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗
Improved coronary CT angiography image quality using photon-counting detector CT in SCAPIS reexamination: scan protocol and comparative analysis.
This European journal of radiology study described the photon-counting detector CT (PCD-CT) coronary CTA protocol in the SCAPIS reexamination population (15,000 participants; analysis included 1,147 participants) and compared diagnostic image quality and quantitative measures against SCAPIS baseline energy-integrating detector CT (EID-CT). PCD-CT produced improved coronary CTA image quality and enabled comparability of Agatston scores and stenosis grading between the two study rounds. The work supports feasibility of population-scale coronary CTA using PCD-CT for more accurate cardiovascular risk and disease monitoring.
Lidén M, Nyberg G, Aurumskjöld ML et al. · European journal of radiology · (2026) · View on PubMed ↗ · Free PDF ↗
Neurovascular CT angiography & stent follow-up
Diagnostic Performance of Photon-Counting Detector CT Angiography in the Detection of Cerebral and Carotid Artery Stenosis.
This prospective cohort study compared ultra-high-resolution (UHR) photon-counting detector CT angiography (PCD-CTA) with standard-resolution (SR) CTA for detecting cerebral and carotid artery stenosis, using digital subtraction angiography (DSA) as the reference standard. The key finding was that UHR PCD-CTA provides diagnostic performance for stenosis assessment that can be directly benchmarked against SR CTA from the same raw data. Clinically, this supports evidence-based selection of UHR photon-counting CTA reconstructions for improved evaluation of vascular stenosis.
Li Z, Jiang H, Zhang Y et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗ · Free PDF ↗
Ultra-High-Resolution Photon-Counting CT Angiography for Noninvasive Detection of Neurovascular In-Stent Restenosis.
This prospective study evaluated ultra-high-resolution photon-counting detector CT angiography (UHR PCD-CTA) in consecutive patients with neurovascular stents to noninvasively detect in-stent restenosis (ISR). UHR PCD-CTA improved visualization and reduced blooming/artifact limitations seen with conventional energy-integrating CTA, enabling more accurate ISR detection. The findings support UHR photon-counting CTA as a clinically useful, noninvasive follow-up tool for neurovascular stent patients where DSA is typically invasive.
Su CQ, Zhou C, Wu PF et al. · Stroke · (2026) · View on PubMed ↗ · Free PDF ↗
Ultra-high resolution Photon-Counting CTA for follow-up assessment of intracranial aneurysms after flow diverter: Initial experience.
This prospective initial-experience study assessed ultra-high-resolution photon-counting CT angiography (UHR-PCCTA) for follow-up after intracranial aneurysm treatment with flow diverters, comparing UHR-PCCTA and standard-resolution (SR) PCCTA against digital subtraction angiography (DSA) in 47 treated participants. UHR-PCCTA improved post-flow-diverter evaluation of aneurysm size and occlusion-related parameters with better artifact reduction than conventional-resolution PCCTA and without requiring invasive DSA. The results suggest UHR-PCCTA could become a less invasive, more accurate imaging alternative for routine post-treatment aneurysm surveillance.
Li R, He N, Cui Y et al. · European journal of radiology · (2026) · View on PubMed ↗
Peripheral arterial disease (PAD) & lower-extremity CTA
Photon-counting detector computed tomography angiogram more accurately characterizes lower extremity runoff than traditional computed tomograph angiogram.
In a single-center retrospective cohort, this study compared lower extremity photon-counting detector CT angiography (PCD-CT; n=43) with conventional energy-integrating detector CT angiography (EID-CTA; n=46) against on-table angiography to characterize tibial artery targets for potential bypass. PCD-CT more accurately identified the target tibial artery, with fewer discrepancies versus angiography (4.6% vs 21.7% for EID-CTA; P=.03). This is clinically significant because improved tibial runoff characterization can directly affect surgical planning and outcomes in peripheral arterial disease.
MacArthur TA, Rajiah PS, Schaller MS · Journal of vascular surgery cases and innovative techniques · (2026) · View on PubMed ↗ · Free PDF ↗
Technical advances and clinical impact of photon-counting computed tomography angiography for peripheral artery disease.
This narrative review summarized technical advances and clinical evidence for photon-counting CT angiography (PCCTA) in peripheral artery disease (PAD), focusing on limitations of conventional CTA such as calcium blooming and beam hardening. It reported that PCCTA has the potential to improve image quality and diagnostic performance in small, heavily calcified vessels by leveraging photon-counting spectral information. The significance is that it frames how PCCTA could enhance diagnosis, procedural planning, and postintervention surveillance in PAD patients where conventional CTA is often less reliable.
Zivkovic M, Raskin D, Ghibes P et al. · Journal of vascular surgery cases and innovative techniques · (2026) · View on PubMed ↗ · Free PDF ↗
Critical care & emergency imaging with spectral CT
Photon-counting CT versus energy-integrating CT of the chest in acute respiratory distress syndrome: A retrospective observational study of image quality and radiation exposure.
This retrospective observational study performed intraindividual comparisons of contrast-enhanced chest photon-counting detector CT (PCD-CT) versus energy-integrating detector CT (EID-CT) in patients with acute respiratory distress syndrome (ARDS). PCD-CT showed differences in image quality and radiation exposure relative to EID-CT, suggesting potential for improved imaging and dose optimization in critically ill patients. These data strengthen the evidence base for adopting photon-counting CT in ARDS imaging where both diagnostic clarity and radiation minimization are important.
Rosok D, Opitz M, Bos D et al. · Emergency radiology · (2026) · View on PubMed ↗ · Free PDF ↗
Dual-energy and photon-counting computed tomography in critical care.
This review studied the role of dual-energy CT (DECT) and photon-counting CT (PCD-CT) in critical care, focusing on how spectral reconstructions such as iodine maps and virtual non-contrast images affect diagnostic performance and contrast/radiation exposure. It found that spectral CT techniques can enable rapid, accurate material differentiation in critically ill patients while potentially reducing contrast dose and radiation, with particular emphasis on pulmonary embolism assessment using iodine perfusion maps. The scientific significance is that these imaging capabilities may support life- or organ-saving decisions in emergency and intensive care settings by improving diagnostic confidence under constraints of patient stability and contrast safety.
Freed A, Bogot NR, Einav S · Journal of critical care · (2026) · 1 citations · View on PubMed ↗
Musculoskeletal CT (bone/fracture/temporal bone/endodontics)
Multireader Comparison of Photon-Counting Detector CT Reconstructions for Evaluation of Temporal Bone Cochlear Implants.
This multireader study evaluated six different photon-counting CT (PCCT) reconstruction approaches for temporal bone imaging of cochlear implants in 20 patients (24 implants) scanned on a NAEOTOM Alpha photon-counting CT system. The key finding was that reconstruction algorithm choice affects image quality and diagnostic evaluation of cochlear implant-related temporal bone structures in a reader-dependent manner. This is significant for establishing PCCT reconstruction parameters that optimize cochlear implant imaging quality and reliability.
Dogra S, O’Donnell T, Nayak G et al. · AJNR. American journal of neuroradiology · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗
Musculoskeletal Computed Tomography Imaging: A 30-Year Perspective.
This 30-year perspective review synthesized major developments in musculoskeletal computed tomography (CT), emphasizing how advances in hardware and acquisition (e.g., helical and high-resolution dose-efficient systems) improved bone and fracture assessment. It highlighted that spectral CT enables characterization of crystal deposits and marrow edema and supports metal artifact reduction, while other CT variants such as weight-bearing cone-beam CT and CT arthrography expand functional and intra-articular evaluation. The significance is that it provides a high-level scientific roadmap for how evolving CT technologies translate into improved diagnostic capabilities in musculoskeletal care.
Omoumi P, Pastor M, Demehri S et al. · Seminars in musculoskeletal radiology · (2026) · View on PubMed ↗
Photon-Counting Detector CT-Based Virtual Monoenergetic Imaging With Metal Artifact Reduction for Endodontic Diagnostics.
This ex vivo study evaluated photon-counting detector CT (PCD-CT) virtual monoenergetic imaging (VMI) across 70–190 keV for endodontic diagnostics in 16 extracted human third molars with simulated diagnostic challenges, and tested iterative metal artifact reduction (iMAR). The key finding was that an optimal VMI energy level and the addition of iMAR improved diagnostic accuracy and depiction quality while reducing metal artifact severity for simulated endodontic complications at radiation doses comparable to standard-dose cone-beam CT. Scientifically and clinically, the results support using PCD-CT VMI plus iMAR to better visualize endodontic pathology in the presence of metallic-related artifacts.
Al-Haj Husain A, Dogan S, Mergen V et al. · International dental journal · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗
Dual-energy CT for detection of knee fractures as alternative to MRI.
This narrative review studied the use of dual-energy CT (DECT) in acute knee trauma patients as an alternative to MRI, focusing on DECT techniques such as virtual non-calcium reconstructions for bone marrow edema detection and spectral/metal artifact reduction methods. The key finding is that DECT can provide clinically useful information for fracture detection and characterization—particularly for complex articular fractures, subtle impacted fractures, and stress fractures/healing assessment—by leveraging its spectral analysis and virtual non-calcium imaging. Clinically, DECT may reduce reliance on MRI in selected knee injury scenarios by improving detection of marrow edema and fracture-related findings while potentially offering faster, more widely available imaging.
Foti G, Tripodi G, Ocello G et al. · Skeletal radiology · (2026) · 1 citations · View on PubMed ↗
Non-cardiac abdominal & GI oncology imaging with PCCT
Improved pancreatic imaging with photon-counting CT: a retrospective comparison with conventional CT.
This retrospective study compared photon-counting CT (PCCT) with conventional energy-integrating CT (EID-CT) for pancreatic imaging in 35 patients who underwent both modalities across multiple contrast phases. PCCT provided superior image quality across 11 peripancreatic regions on Likert-based subjective scoring and showed quantitative differences in density and noise measured by a single reader. The findings are important because they support PCCT as a technique that can improve visualization of pancreatic pathology while potentially optimizing contrast-to-noise characteristics.
Brandt EGS, Christoph Müller F, Nielsen YJ et al. · Acta radiologica (Stockholm, Sweden : 1987) · (2026) · View on PubMed ↗
Photon-counting CT in gastrointestinal malignancies: a scoping review.
This scoping review mapped clinical evidence for photon-counting CT (PCCT) in gastrointestinal malignancies in adult patients, following PRISMA-ScR methodology and grading evidence levels. It summarized how PCCT’s improved spatial resolution, contrast-to-noise ratio, and potential radiation dose reduction have been applied across GI oncology imaging tasks. The review identifies current evidence gaps and helps guide future clinical trials and technology adoption in GI cancer imaging.
Spoto F, Robertis R, Monterubbiano L et al. · European journal of radiology · (2026) · View on PubMed ↗
Diagnostic performance of photon-counting detector CT versus energy-integrating detector CT for colorectal polyp detection: a phantom study.
This phantom study compared photon-counting detector CT (PCD-CT) with energy-integrating detector CT (EID-CT) for colorectal polyp detection using 84 histopathologically confirmed polyps from resected specimens. The key finding was that PCD-CT and EID-CT differed in image quality metrics (including SNR and CNR) and in detection sensitivity/diagnostic confidence across polyp size categories (≤5 mm, 6–9 mm, ≥10 mm). The clinical significance is that PCD-CT may offer improved detection performance for colorectal polyps, particularly for smaller lesions where diagnostic accuracy is most challenging.
Wu X, Gao H, Gao Y et al. · Abdominal radiology (New York) · (2026) · View on PubMed ↗
Pulmonary imaging & pulmonary embolism/perfusion mapping
Comparative accuracy of photon-counting and dual energy CT pulmonary angiography perfusion mapping using V/Q scans as reference standard.
This retrospective study compared photon-counting detector CT (PCD-CT) versus dual-energy CT (DECT) perfusion mapping for pulmonary angiography using ventilation–perfusion (V/Q) SPECT/CT as the reference standard across two independent clinical cohorts. The key finding was that diagnostic performance metrics (accuracy, sensitivity, specificity, PPV, and NPV) for lobar perfusion differed between PCD-CT and DECT when benchmarked against V/Q SPECT/CT, with quantitative iodine density reference values derived for interpretation. The clinical significance is improved selection and standardization of spectral CT perfusion techniques for pulmonary embolism and related indications where V/Q SPECT/CT is used as a comparator.
Ogbonna A, Chamberlin JH, Baruah D et al. · Emergency radiology · (2026) · View on PubMed ↗ · Free PDF ↗
Cardiac/vascular plaque characterization & vulnerability biomarkers
Carotid Imaging: Current Concepts and Advanced Imaging.
This review studied advanced carotid imaging approaches beyond luminal stenosis, including ultrasound, CTA, MRI, digital subtraction angiography, photon-counting CT (PCCT), and PET, to capture plaque biology such as intraplaque hemorrhage, lipid-rich necrotic core, fibrous cap rupture, ulceration, and perivascular inflammation. The key finding is that multimodal plaque phenotyping better reflects vulnerability than stenosis severity alone, and PCCT is positioned as an emerging tool within this multimodal framework. Clinically, the synthesis supports shifting carotid risk stratification toward imaging biomarkers of plaque composition and inflammation to better predict ischemic stroke risk.
Saba L, Pinna A, Suri JS et al. · Seminars in neurology · (2026) · View on PubMed ↗
Photon-counting CT characterization of carotid perivascular adipose tissue: a layer-by-layer quantitative analysis. A preliminary analysis in an asymptomatic population.
This retrospective preliminary study used photon-counting CT (PCCT) angiography in 20 asymptomatic patients to characterize carotid perivascular adipose tissue (PVAT) with a layer-by-layer quantitative analysis using a custom Python segmentation algorithm. The key finding was that PCCT-derived PVAT measurements show spatial behavior and variability across concentric perivascular layers in an asymptomatic cohort. Scientifically, the work supports PVAT quantification as a potentially informative imaging biomarker of carotid vulnerability beyond luminal stenosis.
Saba L, Alkadhi H, Maffei E et al. · European radiology · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗
Quantitative biomarkers (ECV, fibrosis, tissue characterization)
Extracellular volume fraction by cardiac computed tomography (ECVCT): opportunities and challenges for clinical implementation.
This review article summarized how cardiac CT-derived extracellular volume fraction (ECVCT) is calculated in single-energy CT and how spectral CT—particularly photon-counting CT (PCCT)—may enable ECVCT estimation with reduced dependence on separate true non-contrast scans. The key finding was that PCCT-based ECVCT has opportunities (energy-resolved quantification, potential workflow simplification) but also implementation challenges that must be addressed for clinical adoption. Scientifically and clinically, it frames how PCCT could improve fibrosis and amyloid assessment while highlighting practical barriers such as protocol standardization and validation.
Gray R, Rauseo E, Herrey A et al. · European heart journal. Imaging methods and practice · (2026) · View on PubMed ↗ · Free PDF ↗
Photon-counting CT Extracellular Volume Fraction for Liver Fibrosis Assessment: Validation against MR Elastography and Histopathology.
This prospective study assessed whether photon-counting CT (PCCT) extracellular volume fraction (ECV) can stage liver fibrosis by correlating PCCT-derived ECV with MR elastography-derived liver stiffness (LSM) and comparing diagnostic performance against histopathology. The key finding was that PCCT-derived ECV is feasible for liver fibrosis assessment and shows measurable agreement with MR elastography and histopathologic staging. This is significant because it supports PCCT as a noninvasive quantitative imaging biomarker for liver fibrosis evaluation.
Wu X, Li J, Deng R et al. · Radiology · (2026) · View on PubMed ↗
Dose efficiency & pediatric/contrast dose optimization
Obese patient imaging: Potential dose reduction with photon-counting CT.
This phantom study compared cadmium-zinc-telluride (CZT) photon-counting CT (PCCT) versus energy-integrating detector CT (EID-CT) for dose efficiency across increasing phantom sizes representing adult waist percentiles. The key finding was that PCCT can be more dose-efficient than EID-CT in larger/obese patient-equivalent phantoms, improving noise performance at comparable CTDIvol ranges. Clinically, this supports using PCCT to reduce radiation dose while maintaining image quality in obese patients.
Liu LP, Mei K, Sharma S et al. · Journal of applied clinical medical physics · (2026) · View on PubMed ↗ · Free PDF ↗
Photon Counting CT of the Head: Retrospective Analysis of Image Quality and Dose in Comparison to Energy Integrating Detector CT.
This retrospective analysis compared non-contrast head CT (NCCT) performed on photon-counting detector CT (PCD-CT) at 120 and 140 kVp across varying radiation doses versus a modern energy-integrating detector CT (EID-CT) system. Across acquisition parameter changes, PCD-CT demonstrated differences in image quality and radiation metrics relative to EID-CT, supporting dose–image-quality optimization under specific kVp settings. These results provide practical evidence for selecting PCD-CT protocols for emergency NCCT while maintaining diagnostic image quality.
Schoenbeck D, Kroeger JR, Moenninghoff C et al. · Academic radiology · (2026) · View on PubMed ↗ · Free PDF ↗
Dose optimization for pediatric chest CT: a comparative study of energy-integrating and photon-counting detector CT using 70 kV and 100 kV protocols with tin filtration regarding image quality and dose exposure.
This comparative phantom-and-clinical study evaluated pediatric chest CT dose optimization by comparing energy-integrating CT (EICT) versus photon-counting CT (PCCT) using 70 kV and 100 kV protocols with tin filtration (100Sn), with dose measured using thermoluminescent dosimeters (TLDs) and clinical image-quality data. Under matched image-quality conditions, PCCT achieved different (generally lower) radiation dose metrics while maintaining comparable image quality relative to EICT. The results inform pediatric protocol selection to reduce exposure without compromising diagnostic performance.
Kunert P, Weis M, Schlattl H et al. · European journal of radiology · (2026) · View on PubMed ↗ · Free PDF ↗
Ultra-high resolution photon-counting CT of the lung after lung transplantation: should we go for optimal image quality or reduced radiation dose?
This study evaluated ultra-high-resolution photon-counting CT (UHR-PCCT; 0.4 mm) versus high-resolution energy-integrating detector CT (HR-EIDCT; 1.0 mm) in 100 lung-transplant recipients, comparing normal image quality (IQ100) and reduced-dose image quality (IQ40) settings. The investigators assessed whether UHR-PCCT could maintain or improve lung imaging quality while reducing radiation dose compared with prior EIDCT. The findings address the key follow-up dilemma in lung transplant patients—maximizing detail for longitudinal monitoring while minimizing cumulative radiation.
Dubbeldam A, Van Ballaer V, Verschakelen J et al. · JHLT open · (2026) · View on PubMed ↗ · Free PDF ↗
A Practical Rule-of-Thumb to Adapt Contrast Media Dose in Photon-counting Detector CT: The 10-to-5 Rule.
This phantom-based experimental study developed a practical contrast-dose adjustment rule—the “10-to-5 rule”—for photon-counting detector CT (PCD-CT) when lowering virtual monoenergetic image (VMI) energy while maintaining parenchymal CT and CTA contrast-to-noise ratio (CNR). Using spectral abdominal and chest CT phantoms with iodine-in-water equivalent rods scanned on a first-generation dual-source PCD-CT, the key finding was that reducing contrast dose according to the 10-to-5 relationship can preserve CNR under VMI energy reduction. Scientifically and clinically, the rule-of-thumb provides a simple method to reduce contrast medium dose in PCD-CT protocols without substantially sacrificing image contrast.
Jeukens CRLPN, Martens B, Vandewall J et al. · Investigative radiology · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗
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