What’s New in Photon Counting CT?

July 08, 2026 · 24 articles · 15 research themes · covering July 01, 2026 – July 08, 2026

Overview

Across this week’s set of studies and reviews, a clear theme is that photon-counting CT (PCD/PCCT) value increasingly depends on how the data are reconstructed and quantified—not just on the detector hardware. Multiple papers show that reconstruction choices (e.g., isotropic voxel spacing, iterative/metal-artifact reduction presets, and post hoc AI denoising) can materially change image quality and diagnostic confidence. In parallel, several works emphasize the practical importance of virtual monoenergetic reconstructions and energy-dependent thresholds for improving consistency (e.g., coronary calcium scoring variability) and for reducing diagnostic pitfalls in challenging anatomy (e.g., pediatric musculoskeletal “pseudo-tumor” interpretation).

A second dominant thread is the move from qualitative imaging to spectral and quantitative biomarkers that can answer specific clinical questions. Material decomposition and derived parameters (iodine/gadolinium/calcium separation; effective atomic number and density) are being developed to provide more specific tissue characterization. Clinically, this is reflected in studies linking PCD-CT spectral metrics to disease biology and outcomes: differentiating neoplastic vs bland portal vein thrombosis in HCC, predicting NSCLC PD-L1 expression categories, and characterizing left ventricular hypertrophy phenotypes in hypertrophic and amyloid cardiomyopathy—each with performance comparable to established reference approaches.

Finally, the digest highlights expanding application domains and workflow integration. PCCT/PCD-CT is being tested for extremity PAD (including optimization for below-knee CTA and knee-arthroplasty artifact mitigation), breast cancer staging with MRI-like lesion conspicuity from single-phase acquisitions, and neurovascular evaluation in spontaneous intracranial hypotension where PCD-CT myelography improves diagnostic certainty. Complementing these empirical studies, narrative and practical reviews synthesize evidence across thoracic oncology, abdominal imaging workflows, orbital imaging, and temporal bone imaging—collectively pointing toward more tailored protocol selection and evidence-based follow-up reduction as key steps for clinical adoption.

---

Photon-Counting CT Physics & Reconstruction Optimization

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 assessed whether deep learning-based denoising (post hoc AI denoising) improves image quality and diagnostic confidence in neurovascular ultrahigh-resolution photon-counting CT angiography (UHR PCD-CTA). In 42 patients undergoing clinically indicated head and neck UHR PCD-CTA reconstructed with vendor iterative reconstruction (level 4) with and without additional AI denoising, the key finding was that AI denoising can enhance image quality and diagnostic confidence, particularly in noise-limited and artifact-prone regions such as the lower neck. Clinically, this supports using AI denoising to better exploit UHR PCD-CTA’s spatial detail while mitigating noise-related diagnostic limitations.

Tóth A, Hagar MT, Silbergleit M et al. · AJNR. American journal of neuroradiology · (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 study investigated how tube voltage, tube current (dose), slice thickness, and quantum iterative reconstructions (IR 1–4) influence variability of coronary artery calcium (CAC) scoring on photon-counting detector CT (PCD-CT). It found that specific protocol parameter choices (including optimized settings across voltage, dose level, slice thickness, and quantum IR) reduced interscan variability compared with less optimized configurations. The clinical significance is a more reproducible PCD-CT CAC scoring protocol, which can improve consistency for cardiovascular risk stratification across scans and sites.

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

---

Dose–Image Quality Trade-offs & Dose Optimization

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

This study investigated organ dose optimization for a point-of-care forearm photon-counting CT (PCD-CT) using spectral shaping (adjusting source voltage and filtration) and organ absorbed dose estimation rather than CTDI alone. Monte Carlo simulations showed how different voltage/filtration combinations can reduce radiation exposure while maintaining image quality, enabling more patient-relevant organ dose assessment for extremity PCD-CT. This is significant for safer implementation of PCD-CT in clinical workflows by supporting dose-optimization strategies grounded in absorbed dose to organs.

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

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

Using adult and pediatric anthropomorphic head phantoms scanned on photon-counting CT (PCCT) across multiple image quality levels (IQLs), this phantom study quantified how radiation dose metrics (mAs, CTDIvol, DLP, organ doses) relate to signal-to-noise ratio (SNR) in brain parenchyma and bone. Radiation dose increased linearly with IQL, while SNR followed a non-linear trend, enabling identification of PCCT IQL ranges that may optimize dose–image-quality balance. These data provide a practical framework for selecting PCCT settings to improve pediatric and adult head imaging efficiency while controlling dose.

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 ↗

---

Spectral Imaging, Material Decomposition & Quantitative Biomarkers

A pilot study: dual-contrast arthrography using photon-counting detector computed tomography with gadolinium and iodine contrasts.

This pilot study developed a dual-contrast photon-counting CT (PCD-CT) material decomposition method to simultaneously separate and quantify iodine, gadolinium, and calcium in dual-contrast arthrography. Using a benchtop PCD-CT system with calibration phantoms (and an ex vivo pig-tail specimen), the approach enabled spectral separation and quantification of iodine and gadolinium (plus calcium) that is not readily achievable with conventional CT/MR. Scientifically and clinically, this could improve CT/MR-guided arthrography by providing more specific, quantitative contrast information for musculoskeletal evaluation.

Deng X, Day J, Masella O et al. · Physics in medicine and biology · (2026) · View on PubMed ↗ · Free PDF ↗

Potential of quantitative X-ray imaging from photon-counting CT: A novel analysis based on effective atomic number and physical density.

This study developed and demonstrated an algorithm to generate quantitative photon-counting CT (PC-CT) images of effective atomic number (Zeff) and effective physical density (ρeff) derived from virtual monoenergetic images (VMIs) acquired on a clinical PCD-CT system. The key finding is that Zeff and ρeff can be computed from VMI data using a database-fitting approach, providing quantitative parameters that go beyond conventional CT morphology/attenuation values. This is significant because it advances quantitative tissue characterization in lung lesion assessment, potentially improving interpretation of tissue composition and density.

Asahara T, Nishigami R, Kimoto N et al. · Journal of applied clinical medical physics · (2026) · View on PubMed ↗

---

Virtual Monoenergetic Imaging (VMI) & Energy-Dependent Reconstructions

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 interpretation and correctly characterized the pseudo-tumor appearance. The significance is that photon-counting CT virtual non-calcium imaging can reduce misdiagnosis and radiation burden concerns in pediatric musculoskeletal evaluation.

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

---

Coronary CT Angiography (CCTA) & Contrast Delivery Optimization

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

This study developed and validated a personalized iodine delivery rate (IDR) injection protocol for coronary CT angiography (cCTA) on photon-counting CT. It found that an IDR formula derived from an ideal iodine delivery rate (IDRIDEAL) targeting 500 HU in 55 keV reconstructions achieved coronary enhancement equivalence within a predefined HU range (500 ± 50) across validation groups using different injection rates (3.5 and 5.0 mL/s). The clinical significance is more consistent coronary enhancement with photon-counting CT, potentially improving image quality and reducing the need for fixed-rate contrast protocols.

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

---

Cardiac Tissue Characterization (LVH/ECV/Late Iodine Enhancement)

Photon-Counting Computed Tomography for Tissue Characterization in Patients With a Left Ventricular Hypertrophic Phenotype.

This prospective study investigated whether photon-counting computed tomography (PCCT) with late iodine enhancement (LIE) and PCCT-derived extracellular volume (ECV) characterizes left ventricular hypertrophy (LVH) as accurately as cardiac magnetic resonance (CMR) in 182 patients with hypertrophic cardiomyopathy, transthyretin amyloid cardiomyopathy, and secondary LVH. It found that PCCT tissue characterization performance was comparable to CMR overall and across hypertrophic phenotypes (with spectral/tissue metrics derived from PCCT). Clinically, this supports PCCT as a potential alternative or complement to CMR for noninvasive LVH phenotyping and tissue assessment.

De Gori C, Aimo A, Occhipinti M et al. · JACC. Cardiovascular imaging · (2026) · 1 citations · View on PubMed ↗

---

Cardiovascular Calcium Scoring 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 examined how virtual monoenergetic image (VMI) reconstructions and adjusted calcium scoring thresholds affect coronary artery calcium (CAC) scoring variability in photon-counting detector CT (PCD-CT). It found that varying VMI energy levels (50–80 keV) with threshold adjustments further reduced score variability compared with the baseline PCD-CT protocol from Part I. The significance is improved reproducibility of CAC scoring, supporting more reliable cardiovascular risk assessment using PCD-CT.

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

---

Oncology Imaging with Photon-Counting CT (Thoracic/NSCLC/PD-L1)

Quantitative spectral parameters of photon-counting detector CT for noninvasive prediction of PD-L1 expression in non-small cell lung cancer.

This retrospective single-center study evaluated whether quantitative PCD-CT spectral parameters can noninvasively predict programmed death-ligand 1 (PD-L1) expression in 63 patients with non-small cell lung cancer (NSCLC). Using immunohistochemistry to classify PD-L1 (TPS <1%, 1–49%, ≥50%) and measuring arterial/venous lesion CT values at 40, 70, and 100 keV plus iodine concentration, the study found that PCD-CT-derived quantitative spectral metrics are informative for predicting PD-L1 expression categories. Clinically, this could support noninvasive patient stratification for immunotherapy by linking PCD-CT quantitative imaging biomarkers to tumor PD-L1 status.

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

---

Oncology Imaging (Breast Lesions & Lesion Conspicuity)

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 photon-counting detector CT (PCD-CT) using 40-keV and 70-keV virtual monoenergetic images (VMI) for breast cancer lesion conspicuity in 22 women undergoing preoperative staging. It found that lesion conspicuity on 40- and 70-keV VMI from a single arterial-phase PCD-CT acquisition was comparable to dynamic contrast-enhanced T1-weighted MRI (DCE-T1WI) as assessed by three readers. The significance is that photon-counting CT may provide MRI-like lesion visibility for breast cancer staging using a single CT acquisition.

Kawasaki Y, Nakajima M, Yokoyama K et al. · Japanese journal of radiology · (2026) · 1 citations · View on PubMed ↗ · Free PDF ↗

---

Vascular Imaging in Peripheral Artery Disease & Lower Extremities

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

This post hoc analysis evaluated spectral ultrahigh-resolution photon-counting detector CT angiography (PCD-CT, dual-source; spectral-UHR mode) in consecutive patients with below-knee peripheral artery disease undergoing lower-limb CTA, focusing on how isotropic voxel spacing affects image quality and performance. The study found that reconstruction voxel spacing meaningfully influenced image quality metrics and diagnostic performance in spectral-UHR PCD-CT angiography. These findings help optimize extremity-specific isotropic reconstructions to better leverage PCD-CT for noninvasive PAD assessment.

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

---

Portal Vein Thrombosis Characterization (HCC/PVT)

Photon-counting detector CT with iodine quantification: improved distinction between bland and neoplastic portal vein thrombosis.

This retrospective single-center study investigated whether photon-counting detector CT (PCD-CT) iodine density (ID) quantification can distinguish neoplastic from bland portal vein thrombosis (PVT) in 104 patients with suspected PVT and hepatocellular carcinoma. It found that quantitative iodine density measurements from PCD-CT improved diagnostic performance for differentiating neoplastic PVT from bland PVT compared with conventional qualitative criteria. The significance is better prognostic stratification in HCC by enabling more reliable noninvasive characterization of PVT.

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

---

Musculoskeletal Imaging & Arthropathy Biomarkers (OA/Crystals/Arthrography)

The current state of computed tomography in osteoarthritis research.

This review examined how computed tomography (CT) is used in osteoarthritis (OA) research across structural assessment domains in human studies and CT-based modeling workflows. It found that CT’s high-resolution bone visualization enables accurate quantification of osteophytes, subchondral bone cysts, sclerosis, and joint space width (JSW), and supports 3D bone shape modeling and dynamic joint mechanics modeling when combined with other modalities. These CT capabilities improve the scientific measurement of OA phenotypes and biomechanics and can strengthen imaging biomarkers for research and potential translation to clinical trials.

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

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 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. It found that SPCCT performed as the reference ex vivo spectral photon-counting assessment on excised tissue, while the in vivo modalities were compared against reference standards using compensated polarized light microscopy of synovial fluid and histology. Scientifically and clinically, accurate crystal detection can improve diagnosis of crystal arthropathies and refine imaging biomarkers for OA-related crystal deposition.

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

---

Orthopedic/Prosthesis Artifact Management in CT Angiography

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

This study compared iterative metal artifact reduction (IMAR) presets in ultra-high-resolution photon-counting CT angiography (UHR-PCCTA) for patients with total knee endoprostheses. In 25 patients (31 lower extremities) undergoing UHR-PCCTA, the key finding was that different IMAR settings meaningfully affected image quality and visualization of the popliteal vasculature in the presence of knee arthroplasty metal artifacts. The clinical significance is improved noninvasive assessment of peripheral artery disease by optimizing reconstruction parameters to mitigate prosthesis-related artifacts.

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

---

Neurovascular & Intracranial Applications (Myelography/CTA/SIH)

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

This retrospective study compared photon-counting detector CT myelography (PCD-CTM) with energy-integrating detector CT myelography (EID-CTM) for detecting cerebrospinal fluid–venous fistulas (CVFs) in spontaneous intracranial hypotension (SIH). Across 628 CTM examinations in 456 patients (scored with the Duke CSF-Venous Fistula Confidence Score, DCCS), PCD-CTM improved diagnostic certainty for CVF detection compared with EID-CTM. This is significant because higher-resolution PCD-CTM may increase confidence in identifying CVFs, potentially improving diagnostic accuracy and downstream management of SIH.

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

---

Workflow, Evidence Synthesis & Clinical Implementation

Photon-counting detector computed tomography for temporal bone: does higher resolution matter?

This review evaluated photon-counting detector CT (PCD-CT) for temporal bone imaging, focusing on whether its higher spatial resolution improves visualization of submillimeter temporal bone structures compared with conventional energy-integrating detector CT (EID-CT). The key finding is that the emerging temporal-bone PCD-CT literature supports technical advantages (improved spatial resolution, reduced noise, and dose efficiency), but the clinical impact of “higher resolution” specifically remains incompletely established across studies. Clinically, this matters for optimizing temporal bone CT protocols and determining when PCD-CT’s resolution gains translate into better diagnostic decision-making for otologic disease.

Epperson MV, Leng S, Lane JI et al. · Current opinion in otolaryngology & head and neck surgery · (2026) · View on PubMed ↗

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

This practical review assessed strategies to maximize the clinical impact of photon-counting CT (PCD-CT) in abdominal imaging, emphasizing how spectral and quantitative capabilities can be leveraged beyond morphology. The key finding is that PCD-CT enables flexible retrospective reconstructions—such as virtual monoenergetic imaging and material decomposition—that can be tailored to specific abdominal tasks, potentially improving diagnostic performance and workflow. The clinical significance is that radiologists can translate PCD-CT’s inherent spectral/quantitative advantages into more actionable imaging outputs for abdominal disease evaluation.

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

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

This comparative review synthesized evidence on coronary CT angiography (CCTA) versus invasive coronary angiography (ICA), including how underlying technical principles and newer modalities such as photon-counting detector CT (PCD-CT) may affect diagnostic value and outcomes. The key finding is that the literature supports a continuing shift toward noninvasive CCTA for risk stratification, while ICA remains important in selected clinical scenarios, with performance influenced by modality-specific physical limitations and technical advances. Scientifically and clinically, this helps frame where PCD-CT-enabled improvements could further refine coronary imaging pathways and decision-making.

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

Orbital Imaging Modalities and Recent Updates.

This narrative review studied current orbital imaging modalities—including ultrasound (US), CT, MRI, PET, and emerging cone-beam CT and photon-counting CT—in patients with orbital pathology. It found that high-resolution MRI best delineates delicate orbital soft tissues and that cone-beam CT and photon-counting CT may add value for bone and spectral characterization, while each modality provides complementary information (US for superficial structures, CT for bone, MR for tissue characterization, PET for metabolic/biochemical information). The clinical significance is improved selection of the most informative imaging technique for specific orbital questions, potentially reducing diagnostic uncertainty.

Martin S · Radiologic clinics of North America · (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-based study compared abdominopelvic photon-counting CT (PCCT) with conventional dual-energy CT (DECT) and single-energy CT (SECT) in outpatient contrast-enhanced abdominal imaging, assessing radiology report–driven follow-up recommendation rates. PCCT showed a different (reported) follow-up recommendation rate relative to DECT and SECT, with the analysis also examining reasons for recommendations and estimating cost savings from avoided follow-up. The results support evidence-based selection of PCCT protocols to potentially reduce unnecessary downstream imaging in abdominal care pathways.

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

Photon-counting detector computed tomography in thoracic oncology: revolutionizing tumor imaging through precision and detail.

This narrative review synthesized evidence on photon-counting detector CT (PCD-CT) for thoracic oncology, focusing on technical advances (spatial resolution, dose–image-quality trade-offs, and intrinsic spectral imaging) and their clinical applications. The review concludes that PCD-CT can improve tumor imaging by providing more precise detail and spectral information compared with conventional energy-integrating detector CT. By consolidating current literature through May 31, 2025, it offers clinically actionable guidance for adopting PCD-CT in thoracic cancer imaging workflows.

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

---

---

Generated automatically on July 08, 2026. Covers PubMed articles published July 01, 2026 – July 08, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.