What’s New in Photon Counting CT?

September 24, 2026 · 11 articles · 11 research themes · covering September 17, 2026 – September 24, 2026

Overview

Across this week’s set of studies, photon-counting (PCCT) and spectral photon-counting CT (SPCCT) are consistently framed as technologies that translate detector-level advantages—better spatial resolution, noise behavior, and spectral information—into measurable clinical and quantitative gains. Multiple investigations emphasize protocol and parameter optimization (e.g., pediatric tin filtration choices, ultra-low-dose feasibility, and spectral acquisition settings), suggesting the field is moving from “can we image with PCCT?” toward “how do we tune PCCT for specific tasks and patient populations?”

Clinically, the dominant momentum is in cardiovascular and fine-anatomy applications. PCCT is evaluated for coronary stent assessment (in-stent restenosis), for functional evaluation of TAVI prostheses using time-resolved hemodynamic parameters, and for atrial fibrillation risk stratification via epicardial adipose tissue quantification after ablation. In parallel, CT-derived myocardial extracellular volume (ECV) remains a key biomarker target, with systematic review evidence highlighting ongoing work on agreement with cardiac MRI and the potential for photon-counting CT to improve CT-based ECV quantification.

Outside cardiology, the studies extend PCCT’s reach into neurodiagnostics (repeat myelography decision-making in suspected spontaneous intracranial hypotension), otosclerosis (temporal bone PCCT to detect stapes fixation and reduce missed diagnoses), and head & neck imaging (improved visualization of small structures and reduced metal/contrast limitations). Finally, translational research using photon-counting/spectral acquisition continues to broaden PCCT’s role beyond anatomy—supporting quantitative cryoprotectant transport measurements and enabling x-ray–driven nanoparticle activation with fluorescence readouts for future theranostic strategies.

---

Photon-Counting Multi-Spectral CT for Tissue Transport/Cryopreservation

Photon counting multi-spectral x-ray computed tomography of multi-component cryoprotectant diffusion into tissue surrogate.

The study investigated photon-counting multi-spectral X-ray CT (MSCT) with an empirical photon-energy bin selection algorithm to quantify how a ternary cryoprotectant mixture of dimethyl sulfoxide (DMSO), glycerol, and water diffuses into a hydrogel tissue surrogate mimicking human muscle. The authors report that the approach can quantitatively map heterogeneous, spatiotemporal cryoprotectant transport within the phantom. This supports photon-counting MSCT as a noninvasive tool for measuring cryoprotectant diffusion relevant to optimizing cryopreservation and related translational protocols.

Ali AM, Parker JT, Consiglio AN et al. · Physics in medicine and biology · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-Counting CT for Neurodiagnostics (CSF Leak/Fistula Workup)

Diagnostic Yield of Repeat Myelography After an Initial Negative Study in Patients With Suspected Spontaneous Intracranial Hypotension.

This retrospective single-center study evaluated 71 patients with suspected spontaneous intracranial hypotension who had an initial negative or nonlocalizing myelogram (and 13 with unresolved suspicious targets) to determine the diagnostic yield of repeat myelography and predictors of positivity. Repeat myelography produced clinically supported positive findings at a measurable rate, with specific imaging/report features associated with likelihood of a positive result (definite vs suspicious vs negative). The findings inform whether and when to pursue repeat myelography to detect potential CSF-venous fistulas (CVFs) after an initial negative study.

Callen AL, Jenkins K, Bhaumik D et al. · AJNR. American journal of neuroradiology · (2026) · View on PubMed ↗

---

Photon-Counting CT for Cardiac Biomarkers (ECV/Fibrosis)

CT-derived myocardial extracellular volume: current evidence, clinical utility, and the emerging role of photon-counting CT-a systematic review.

This PRISMA-compliant systematic review synthesized evidence on CT-derived myocardial extracellular volume (ECV) as a quantitative biomarker of diffuse myocardial interstitial expansion/fibrosis, focusing on its clinical utility and how photon-counting CT may expand performance. Across included studies, CT-derived ECV showed growing feasibility for myocardial ECV assessment, with ongoing discussion of agreement versus cardiac magnetic resonance (the reference standard) and technical factors affecting accuracy. The review clarifies current clinical roles and highlights photon-counting CT as an emerging technique to improve CT-based ECV quantification.

D’Argenzio J, Stucchi F, Tambè V et al. · European radiology experimental · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-Counting CT Protocol Optimization in Pediatrics

Pediatric Chest Photon-counting CT: Dose and Noise Behavior of Clinical Sn100 kVp and 90 kVp Protocols across Image Quality Levels - a Phantom Study.

In a phantom study, the authors compared pediatric chest photon-counting CT (PCCT) protocols—clinical Sn100 kVp tin-filtered ultra-high resolution (UHR) versus non-tin-filtered 90 kVp standard resolution—across image quality levels using anthropomorphic phantoms aged 1, 5, and 10 years. They found protocol-dependent differences in radiation dose and image noise behavior across image quality levels, quantifying how tin filtration and detector mode affect pediatric imaging performance. These results support evidence-based selection of clinical PCCT parameters to balance dose reduction and diagnostic image quality in children.

Klüner LV, Zensen S, Peuster H et al. · RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin · (2026) · View on PubMed ↗

---

Spectral Photon-Counting CT for Nanoparticle Activation & Fluorescence Theranostics

Optimizing x-ray based multimodal imaging: investigating dose dependency and modulation of fluorescence emission from GdF3nanoparticles doped with terbium using spectral photon counting CT.

This study investigated how spectral photon-counting CT (SPCCT) acquisition parameters influence x-ray–induced activation and fluorescence emission from surface-functionalized gadolinium fluoride–terbium nanoparticles (GdTbF3 NPs) doped into gadolinium fluoride (GdF3) using x-ray–based multimodal imaging. The key finding is that SPCCT irradiation and acquisition settings modulate fluorescence emission and imaging performance, enabling optimization of activation/imaging protocols for GdF3:Tb (GdTbF3) nanoparticle systems. This is significant for developing SPCCT-compatible nanoparticle strategies that combine high-contrast CT with fluorescence readouts for future in vivo theranostic applications.

Akl P, Gautheron A, Antonuccio MN et al. · Physics in medicine and biology · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-Counting CT for Coronary CT Angiography & Stents

In vivo coronary stent evaluation using photon-counting computed tomography: diagnostic performance.

This retrospective single-center study enrolled 141 consecutive patients with coronary stents undergoing coronary CT angiography using photon-counting CT (PCCT) or energy-integrating detector (EID)-CT to assess diagnostic performance for in-stent restenosis (ISR) ≥50% against invasive coronary angiography (ICA). The authors report that PCCT provides diagnostic performance and in-stent lumen image quality that can support detection of clinically relevant ISR, with measurable differences in image quality grading. Clinically, this supports PCCT coronary angiography as a potential noninvasive alternative for evaluating stent patency and ISR severity.

Lacaita PG, Bilgeri V, Spitaler P et al. · European radiology · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-Counting CT for Temporal Bone/Otosclerosis

Photon-counting CT for preoperative assessment of stapes footplate fixation in otosclerosis.

This retrospective case series studied 18 patients with surgically confirmed otosclerosis who underwent temporal bone photon-counting CT (PCCT) to characterize imaging findings of stapes footplate fixation and to assess missed diagnoses on initial radiology reports. PCCT findings such as increased stapes footplate thickness and hypoattenuation correlated with intraoperative confirmation, and the authors identified a frequency of preoperative radiology misses. The work suggests PCCT can improve preoperative detection of stapes fixation, potentially reducing diagnostic delays in otosclerosis management.

Arora M, Seyedsaadat SM, Breen JT et al. · European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery · (2026) · View on PubMed ↗

---

Photon-Counting CT for Lung Imaging & Dose Reduction

Quantitative and qualitative lung parameters in photon-counting CT: comparison of ultra-low-dose with standard low-dose protocols.

In a prospective study of 101 patients, the authors compared same-session ultra-low-dose (ULD) versus standard low-dose (LD) photon-counting CT (PCCT) for lung assessment, using automated quantitative CT (QCT) metrics and reader-based qualitative scoring. They found that ULD PCCT altered quantitative lung parameters and image quality/noise-related measures, with impacts on airway and emphysema-related metrics depending on kernel and segmentation performance. This is significant for defining how far PCCT can be pushed toward ultra-low dose while preserving clinically usable quantitative lung evaluation.

Kroschke J, Jungblut L, von Stackelberg O et al. · European radiology · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-Counting CT for Cardiac Valve Function (TAVI)

Photon-counting detector CT for prediction of valve dysfunction after transcatheter aortic valve implantation: Comparison with echocardiography.

This retrospective single-center study evaluated time-resolved photon-counting detector (PCD)-CT–derived hemodynamic parameters in post–transcatheter aortic valve implantation (TAVI) patients to predict prosthetic valve dysfunction, comparing diagnostic accuracy with echocardiography. The key finding is that PCD-CT functional measurements can provide diagnostic accuracy for valve dysfunction assessment and may complement echocardiography by integrating anatomic and hemodynamic information. This supports broader clinical adoption of time-resolved PCD-CT for noninvasive functional evaluation of TAVI prostheses.

Hyska S, Osoria-Velasquez J, Hagar MT et al. · Journal of cardiovascular computed tomography · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-Counting CT for Atrial Fibrillation & Ablation Biomarkers

Epicardial adipose tissue in paroxysmal and persistent atrial fibrillation ablation using photon counting CT and automated 3D atrial segmentation: The Prospective AFAT Study.

The Prospective AFAT study prospectively enrolled 210 adults undergoing first-time catheter ablation for paroxysmal or persistent atrial fibrillation and used photon-counting CT (PCCT) with semiautomated 3D biatrial segmentation to quantify epicardial adipose tissue (EAT) volume. The study found associations between quantified EAT characteristics and arrhythmia recurrence after ablation, stratifying risk in relation to EAT burden. Scientifically and clinically, this supports PCCT-based volumetric EAT assessment as a potential imaging biomarker for recurrence prediction after AF ablation.

Erhard N, Bahlke F, Prommersberger S et al. · Heart rhythm · (2026) · View on PubMed ↗ · Free PDF ↗

---

Photon-Counting CT in Head & Neck Imaging

Photon-counting CT in head and neck radiology: bridging detector physics and clinical applications.

This review studied photon-counting computed tomography (PCCT) for head and neck radiology, focusing on how detector physics translates into clinical performance compared with conventional energy-integrating CT (EID-CT). It found that PCCT’s improved spatial resolution, reduced image noise and metal artifacts, potential for lower radiation dose, reduced iodinated contrast requirements, and spectral imaging capabilities enable more detailed visualization of small vessels, ossicles, and cartilage for preoperative planning and postoperative assessment. Clinically, these advantages suggest PCCT could improve diagnostic quality and procedural safety in head and neck imaging, particularly in patients where fine anatomy and metal/contrast limitations are important.

Martín-Noguerol T, Escartín J, López-Úbeda P et al. · European radiology · (2026) · View on PubMed ↗

---

---

Generated automatically on September 24, 2026. Covers PubMed articles published September 17, 2026 – September 24, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.