What’s New in Photon Counting CT?

October 21, 2026 · 10 articles · 10 research themes · covering October 14, 2026 – October 21, 2026

Overview

Across this week’s set of studies and reviews, a dominant theme is the rapid expansion of photon-counting and spectral CT from “better images” toward quantitative, decision-relevant biomarkers. Multiple works focus on extracting clinically meaningful metrics—such as iodine concentration for predicting rectal cancer response, quantitative ILD burden from low-dose PCCT, and radiomic features that must be interpreted carefully given platform/reconstruction effects and age-related confounding in preclinical models. In parallel, vascular imaging studies use PCCT to improve visualization and characterization of carotid-related findings (carotid body detection/quantification and resolving carotid web-like appearances), underscoring how detector technology can reduce diagnostic uncertainty.

A second major thread is protocol optimization to balance diagnostic performance with patient safety, particularly radiation and iodine burden. Reviews and feasibility studies emphasize individualized low-iodine DECT pulmonary angiography for pulmonary embolism and explore acquisition-mode choices for coronary CT angiography on photon-counting systems to maintain stenosis assessment accuracy while minimizing dose. Complementing these technical efforts, the cardiac CT narrative review highlights a clinical shift toward using CCTA as a first-line test in appropriately selected patients with stable chest pain or suspected chronic coronary syndromes—moving CT from rule-out imaging toward comprehensive risk assessment and management planning.

Finally, the set highlights a translational bottleneck: standardization. The ASFNR state-of-practice statement on chronic subdural hematoma imaging phenotypes notes that internal hematoma architecture has not yet been standardized or validated for predicting neomembrane activity, recurrence, or treatment selection in randomized trials. Together with the biomarker-focused cancer and ILD studies, this points to a broader field need: harmonized definitions, reproducible quantification, and robust validation frameworks so that advanced CT-derived features can reliably guide clinical decisions.

---

Dual-energy CT pulmonary angiography (DECTPA) and low-iodine protocols for PE

Dual-energy computed tomography pulmonary angiography for pulmonary embolism: a three-tier evidence framework to guide individualized low-iodine scanning.

This narrative review synthesized evidence on dual-energy CT pulmonary angiography (DECTPA) for pulmonary embolism (PE) to support individualized low-iodine scanning. It organized 28 eligible studies into a three-tier framework—image quality, diagnostic performance, and clinical outcomes/implementation—covering protocol heterogeneity across platforms and study designs. The review’s significance is providing a structured approach to selecting low-iodine DECTPA protocols that maintain diagnostic reliability while reducing iodine load.

Jiang Q, Qian L · Diagnostic and interventional radiology (Ankara, Turkey) · (2026) · View on PubMed ↗ · Free PDF ↗

---

Cardiac CT / coronary CT angiography (CCTA) clinical role and first-line testing

The evolving role of cardiac CT: Emerging technologies and clinical impact.

This narrative review studied the evolving clinical role of cardiac computed tomography (CT), focusing on coronary CT angiography (CCTA) and its impact across coronary artery disease, myocardial disease, valvular disease, and structural heart disease. It reports that CCTA is increasingly endorsed as a first-line test for appropriately selected patients with stable chest pain or suspected chronic coronary syndromes, enabling exclusion of obstructive disease and assessment of atherosclerotic burden to guide prevention and referral for invasive angiography. The review highlights how advances in cardiac CT technology are expanding CT from a rule-out tool to a comprehensive platform for diagnosis, risk assessment, and management planning.

Oda S, Iima M, Yanagawa M et al. · Diagnostic and interventional imaging · (2026) · View on PubMed ↗ · Free PDF ↗

---

Coronary CT angiography performance under photon-counting CT acquisition modes

Impact of Photon-Counting CT Acquisition Modes on Coronary Stenosis Assessment and Radiation Dose: A Phantom and Clinical Evaluation.

This phantom-and-clinical evaluation studied how different photon-counting CT acquisition modes affect coronary stenosis assessment and radiation dose using first-generation dual-source photon-counting detector CT. It compared acquisition modes including high-pitch spiral with prospective ECG-gating (Flash), Sequence, Spiral, and retrospective ultra-high-resolution (UHR) spiral, assessing image quality, blooming, stenosis grading, diagnostic accuracy, and dose. The results aim to identify acquisition strategies that optimize coronary CT angiography performance while minimizing radiation exposure.

Stein T, Lang F, Bamberg F et al. · Zeitschrift fur medizinische Physik · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-counting CT quantitative biomarkers for cancer treatment response

Photon-counting computed tomography and magnetic resonance imaging in rectal cancer: reassessment of normalized iodine concentration and apparent diffusion coefficient in an expanded cohort.

This single-center retrospective study evaluated whether pretreatment photon-counting CT (PCCT) normalized iodine concentration (NIC) predicts neoadjuvant treatment response in 63 patients with rectal adenocarcinoma, using MRI-derived apparent diffusion coefficient (ADC) as an internal reference marker. Patients were classified by Dworak tumor regression grade into poor response (grades 0–1) versus moderate/good response (grades 2–4), and the study reassessed NIC in an expanded cohort. If validated, PCCT-derived iodine metrics could improve noninvasive prediction of histopathologic response to neoadjuvant therapy in rectal cancer.

Saeed S, Shahzadi I, Niehoff JH et al. · Abdominal radiology (New York) · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-counting CT radiomics and reproducibility/age confounding (preclinical)

Age-associated radiomic phenotyping in mice using multi-energy photon-counting and preclinical CT: an exploratory study.

This exploratory preclinical study investigated whether CT-derived radiomic features reflect chronological age patterns in female C57BL/6NRj mice across three age groups (28, 88, and 99 weeks) using multi-energy photon-counting CT (PCCT) and preclinical CT. It assessed how imaging platform and reconstruction strategy influence radiomic classification performance, using nested leave-one-mouse-out cross-validation with the mouse as the independent biological unit. The work is significant for understanding age-related confounding and reproducibility of radiomics in PCCT-based preclinical phenotyping.

Castioni NA, Wängler C, Mogler C et al. · Biogerontology · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-counting CT for interstitial lung disease (ILD) quantification and low-dose feasibility

Low-dose vs standard-dose photon-counting CT for myopathy-associated interstitial lung disease: a prospective feasibility study.

This prospective feasibility study compared low-dose versus standard-dose photon-counting CT (PCCT) for quantifying interstitial lung disease (ILD) burden in patients with inflammatory idiopathic myopathy (IIM)-associated ILD. Outpatients underwent two consecutive PCCT scans using tin-filtered low-dose and standard-dose protocols, with quantitative ILD features extracted using ContextFlow ADVANCE Chest CT and analyses including ultrathin reconstructions. The study’s significance is establishing whether PCCT can reduce radiation dose while preserving quantitative ILD assessment in a clinically relevant ILD population.

Zhu Z, Xu K, Pang Y et al. · European radiology · (2026) · View on PubMed ↗

---

Photon-counting CT for vascular imaging biomarkers (carotid body, carotid web)

Carotid Body Detection Rate and Size on Photon-Counting Versus Energy-Integrating Detector CT.

This retrospective study compared carotid body (CB) detection rate and size on photon-counting CT (PCCT) versus energy-integrating detector CT (EIDCT) in 48 adults undergoing head-and-neck CTA at both arterial and venous phases. It used mixed-effects logistic regression for detection and linear mixed-effects modeling for size, evaluating effects of modality, phase, and laterality. The findings are intended to determine whether PCCT improves CB visualization and quantification, which could support more reliable imaging biomarkers for carotid body assessment.

Unger RH, Arizono E, Buch K et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗

Ultra-high-resolution photon-counting CT argues against a suspected bilateral carotid web: a case report.

This case report evaluated a suspected bilateral carotid web in a 75-year-old woman with transient ischemic attack by comparing multiple carotid CTA examinations across CT platforms. It contrasted an earlier dual-energy energy-integrating detector CT (EID-CT) angiogram, a stroke-protocol photon-counting detector CT (PCD-CT) angiogram at presentation, and a dedicated ultra-high-resolution PCCT study to determine whether the web-like appearance was due to acquisition or reconstruction. The clinical significance is demonstrating how ultra-high-resolution photon-counting CT can help resolve diagnostic uncertainty for carotid web-like findings.

Ben-David E, Bogot NR, Berrebi Y et al. · Emergency radiology · (2026) · View on PubMed ↗

---

Imaging biomarkers standardization for chronic subdural hematoma (cSDH) and MMA embolization

ASFNR Clinical State of Practice Statement on Imaging of Chronic Subdural Hematoma.

This article presents an American Society of Functional Neuroradiology (ASFNR) clinical state-of-practice statement on imaging biomarkers for chronic subdural hematoma (cSDH) in the context of middle meningeal artery embolization (MMAE). It emphasizes that cSDH “imaging phenotype” (hematoma internal architecture) has not yet been standardized or validated for predicting neomembrane activity, recurrence, or treatment selection in randomized trials. Standardized definitions and reporting of imaging phenotypes are needed to integrate imaging biomarkers into MMAE decision-making and improve recurrence risk stratification.

Ahmed S, Essibayi MA, Kakadiya J et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗

---

Spectral photon-counting CT (SPCCT) and multimodal nanoparticle contrast agents

Folic Acid-Conjugated Albumin-Stabilized Gold-Terbium Nanoparticles for SPCCT/MRI Imaging: An in vitro Cellular and Phantom Study.

This in vitro cellular and phantom study developed folic acid–conjugated, albumin-stabilized gold-terbium nanoparticles (BSA@Au/Tb-FA) to enable spectral photon-counting CT (SPCCT) and MRI imaging. It characterized the nanoparticles (TEM, XRD, FTIR, XPS, DLS), tested uptake and cytotoxicity in MDA-MB-231 triple-negative breast cancer cells using confocal microscopy and flow cytometry, and evaluated SPCCT/MRI performance in phantom models. The significance is advancing a multimodal nanoparticle contrast agent that could improve imaging of heterogeneous triple-negative breast cancer using SPCCT/MRI.

Ibrahim YO, Maalej N, Raja AY et al. · International journal of nanomedicine · (2026) · View on PubMed ↗

---

---

Generated automatically on October 21, 2026. Covers PubMed articles published October 14, 2026 – October 21, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.