What’s New in Photon Counting CT?

August 23, 2026 · 4 articles · 5 research themes · covering August 16, 2026 – August 23, 2026

Overview

Across these studies, photon-counting detector CT (PCD-CT) is being pushed beyond “better pictures” toward more decisive diagnostic performance and more streamlined workflows. Two investigations focus on spectral reconstruction strategies—using virtual unenhanced images and iodine maps for characterizing hyperdense adnexal lesions, and testing low-keV virtual monoenergetic images to improve contrast for detecting muscle invasion in bladder cancer. Together, they highlight a common theme: leveraging PCD-CT’s spectral information to reduce diagnostic uncertainty and potentially limit additional or delayed imaging.

A second theme is protocol and acquisition optimization to preserve diagnostic accuracy while improving practicality. In coronary CT angiography, a retrospective study evaluates whether sublingual nitroglycerin is truly necessary for diagnostic accuracy on photon-counting CT, addressing whether medication can be omitted without loss of performance. In parallel, a feasibility study introduces a single-phase spectral black-blood PCD-CT approach for carotid vessel wall imaging, showing how iodine suppression settings can be tuned to balance intraluminal suppression with plaque-wall preservation—aiming to enhance visualization of plaque morphology relevant to stroke risk.

---

Spectral Imaging for Lesion Characterization

Distinguishing enhancing from non-enhancing hyperdense adnexal lesions with spectral reconstructions at photon counting CT.

This retrospective study in adult women with hyperdense adnexal lesions on contrast-enhanced photon-counting CT (PCCT) assessed whether spectral reconstructions—virtual unenhanced (VUE) and iodine maps—can distinguish enhancing from non-enhancing lesions, using pelvic MRI or ultrasound within 180 days as the reference standard (lesions >1 cm and >20 HU on 70 keV images). The key finding was the utility of PCCT spectral reconstructions to differentiate enhancing versus non-enhancing hyperdense adnexal lesions, potentially reducing indeterminate follow-up. Clinically, improved characterization of hyperdense adnexal lesions could support more confident triage and management decisions without relying solely on delayed imaging.

Rigau D, Parrott D, Bansal B et al. · Abdominal radiology (New York) · (2026) · View on PubMed ↗

---

Low-Energy/Monoenergetic Reconstruction for Diagnostic Performance

Photon-Counting CT With Low-keV Virtual Monoenergetic Images for Detecting Muscle Invasion in Bladder Cancer: A Prospective Study.

This prospective study enrolled patients with pathologically confirmed bladder cancer who underwent preoperative photon-counting detector CT (PCD-CT) between August 2025 and March 2026 to compare low-keV virtual monoenergetic images (VMIs at 40, 50, 60, and 70 keV) versus conventional polychromatic images for detecting muscle invasion. Low-keV VMIs on PCD-CT were evaluated for improved lesion-to-background contrast and diagnostic performance for muscle invasion. If validated, this technique could enhance local staging accuracy in bladder cancer, potentially improving treatment planning for patients needing definitive therapy.

Wang W, He J, Wu J et al. · AJR. American journal of roentgenology · (2026) · View on PubMed ↗ · Free PDF ↗

---

Black-Blood Vessel Wall Imaging & Plaque Assessment

Spectral Black-Blood Photon-Counting CT for High-Resolution Carotid Vessel Wall Imaging: A Feasibility Study.

This retrospective feasibility study evaluated a novel single-phase spectral black-blood photon-counting CT (BBCT) technique for high-resolution carotid vessel wall imaging using clinically indicated head-and-neck PCD-CT angiography data, with spectral iodine suppression and nine iodine ratio (IR) settings to balance intraluminal suppression and vessel wall preservation (n=9 iodine ratio settings; truncated abstract). The study demonstrated feasibility of generating high-resolution BBCT reconstructions from a single angiographic-phase dataset and explored how iodine suppression settings affect plaque feature visualization. Scientifically and clinically, this approach could improve visualization of carotid plaque morphology, supporting better assessment of plaque characteristics relevant to stroke risk.

Tóth A, Hagar MT, Halfmann MC et al. · Investigative radiology · (2026) · View on PubMed ↗

---

Cardiac CT Angiography Diagnostic Accuracy

Is nitroglycerin still necessary for coronary CT angiography in the era of photon-counting CT?

This retrospective single-center study evaluated whether sublingual nitroglycerin is necessary for diagnostic accuracy of photon-counting detector CT (PCD-CT) coronary CT angiography (CCTA) by comparing patients who underwent PCD-CT CCTA with invasive coronary angiography (ICA) within 30 days (124 total patients; 61 received nitroglycerin, truncated abstract). Nitroglycerin’s effect on coronary visualization was assessed in the context of photon-counting CT, addressing a gap because prior evidence largely came from older CT generations and focused on image quality rather than diagnostic performance. If nitroglycerin is shown to add little diagnostic value on PCD-CT, it could streamline CCTA protocols and reduce unnecessary medication use while maintaining accuracy.

Kabakus IM, Maisuria DM, Chamberlin JH et al. · Journal of cardiovascular computed tomography · (2026) · View on PubMed ↗

---

---

Generated automatically on August 23, 2026. Covers PubMed articles published August 16, 2026 – August 23, 2026. Summaries are AI-generated; always consult the original publication for clinical or research decisions.