Photon-Counting Computed Tomography – Basic Principles, Potenzial Benefits, and Initial Clinical Experience

Abstract

Background Photon-counting computed tomography (PCCT) is a promising new technology with the potential to fundamentally change today’s workflows in the daily routine and to provide new quantitative imaging information to improve clinical decision-making and patient management.

Method The content of this review is based on an unrestricted literature search on PubMed and Google Scholar using the search terms “Photon-Counting CT”, “Photon-Counting detector”, “spectral CT”, “Computed Tomography” as well as on the authors’ experience.

Results The fundamental difference with respect to the currently established energy-integrating CT detectors is that PCCT allows counting of every single photon at the detector level. Based on the identified literature, PCCT phantom measurements and initial clinical studies have demonstrated that the new technology allows improved spatial resolution, reduced image noise, and new possibilities for advanced quantitative image postprocessing.

Conclusion For clinical practice, the potential benefits include fewer beam hardening artifacts, radiation dose reduction, and the use of new contrast agents. In this review, we will discuss basic technical principles and potential clinical benefits and demonstrate first clinical use cases.

Key Points: 

• Photon-counting computed tomography (PCCT) has been implemented in the clinical routine

• Compared to energy-integrating detector CT, PCCT allows the reduction of electronic image noise

• PCCT provides increased spatial resolution and a higher contrast-to-noise ratio

• The novel detector technology allows the quantification of spectral information

Citation Format

• Stein T, Rau A, Russe MF et al. Photon-Counting Computed Tomography – Basic Principles, Potenzial Benefits, and Initial Clinical Experience. Fortschr Röntgenstr 2023; 195: 691 – 698

Zusammenfassung

Hintergrund Die Technologie der Photonen zählenden Computertomografie hat Einzug in die klinische Praxis gehalten und wird erstmals in der klinischen Routine eingesetzt. Während die ersten Erfahrungen mit diesem Verfahren in bestimmten Patientengruppen gemacht werden, hat die Technologie das Potenzial, bestehende Arbeitsabläufe zu verändern und öffnet neue Möglichkeiten in der diagnostischen Bildgebung.

Methode Der Inhalt dieser Übersicht basiert auf einer uneingeschränkten Literaturrecherche in den Datenbanken PubMed und Google Scholar unter der Verwendung der Suchbegriffe “Photon-Counting CT”, “Photon-Counting detector”, “spectral CT”, “Computed Tomography” sowie auf den Erfahrungen der Autoren.

Ergebnisse Der grundlegende Unterschied zu den derzeit etablierten energieintegrierenden CT-Detektoren besteht darin, dass die PCCT die Zählung jedes einzelnen Photons auf Detektorebene ermöglicht. Basierend auf der identifizierten Literatur haben PCCT-Phantommessungen und erste klinische Studien gezeigt, dass die neue Technologie eine verbesserte räumliche Auflösung, eine reduziertes Bildrauschen und neue Möglichkeiten für neue quantitative Bildnachbearbeitung ermöglicht.

Schlussfolgerung PCCT ist eine neuartige, innovative Technologie mit dem Potenzial, viele der derzeitigen Einschränkungen der CT-Bildgebung in der klinischen Praxis zu überwinden. In diesem Review diskutieren wir grundlegende technische Prinzipien, potenzielle klinische Vorteile und demonstrieren erste klinische Anwendungsfälle.

Kernaussagen 

• Die Photon-Counting-Computertomografie (PCCT) wird erstmals in der klinischen Routine eingesetzt

• Verglichen mit herkömmlichen CT ermöglicht die PCCT eine Reduzierung des elektronischen Bildrauschens

• PCCT bietet eine höhere räumliche Auflösung und ein besseres Kontrast-Rausch-Verhältnis

• Die neuartige Detektortechnologie ermöglicht die Quantifizierung von spektralen Bildinformationen

Key words

Photon Counting - Computed Tomography - Diagnostic Imaging - Spectral Computed Tomography - Photon-Counting Detector - Energy-Integrating Detectors

Publication History

Received: 29 August 2022

Accepted: 18 January 2023

Article published online:
02 March 2023

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