Coronary Calcium Scoring with First Generation Dual-Source Photon-Counting CT-First Evidence from Phantom and In-Vivo Scans.

Matthias Eberhard,Andre Euler,Hatem Alkadhi,Bernhard Schmidt,Robert Manka,Victor Mergen,Kai Higashigaito,Thomas Allmendinger,Thomas Flohr

doi:10.3390/diagnostics11091708

Matthias Eberhard, Andre Euler + Show 7 more

Open Access

https://doi.org/10.3390/diagnostics11091708

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Abstract

We evaluated the accuracy of coronary artery calcium (CAC) scoring on a dual-source photon-counting detector CT (PCD-CT). An anthropomorphic chest phantom underwent ECG-gated sequential scanning on a PCD-CT at 120 kV with four radiation dose levels (CTDIvol, 2.0–8.6 mGy). Polychromatic images at 120 kV (T3D) and virtual monoenergetic images (VMI), from 60 to 75 keV without quantum iterative reconstruction (no QIR) and QIR strength levels 1–4, were reconstructed. For reference, the same phantom was scanned on a conventional energy-integrating detector CT (120 kV; filtered back projection) at identical radiation doses. CAC scoring in 20 patients with PCD-CT (120 kV; no QIR and QIR 1–4) were included. In the phantom, there were no differences between CAC scores of different radiation doses (all, p > 0.05). Images with 70 keV, no QIR (CAC score, 649); 65 keV, QIR 3 (656); 65 keV; QIR4 (648) and T3D, QIR4 (656) showed a <1% deviation to the reference (653). CAC scores significantly decreased at increasing QIR levels (all, p < 0.001) and for each 5 keV-increase (all, p < 0.001). Patient data (median CAC score: 86 [inter-quartile range: 38–978] at 70 keV) confirmed relationships and differences between reconstructions from the phantom. First phantom and in-vivo experience with a clinical dual-source PCD-CT system shows accurate CAC scoring with VMI reconstructions at different radiation dose levels.

Highlights

Cardiovascular risk assessment is crucial for the prevention of adverse cardiovascular events [1,2,3]
Compared to well established clinical risk scores [4,5,6], the coronary artery calcium scoring (CAC) score provides incremental prognostic information predicting the risk of future events
Our first phantom and in-vivo experience suggests that CAC scoring on a clinical dual-source

Summary

Introduction

Cardiovascular risk assessment is crucial for the prevention of adverse cardiovascular events [1,2,3]. Compared to well established clinical risk scores [4,5,6], the coronary artery calcium scoring (CAC) score provides incremental prognostic information predicting the risk of future events. EBCT has been surpassed by helical energy-integrating detector. Compared to EID-CT, photon-counting detector CT (PCD-CT) represents a fundamentally different approach for CT imaging [11,12,13]. Photon-counting detectors count the number of incoming photons and the electronic signal is proportional to the deposited energy of each photon [11]. The first whole-body, full field-of-view dual-source PCD-CT system was cleared for clinical use. With this PCDCT scanner, the new standard of post-processing is virtual monoenergetic images (VMI), which are directly and automatically generated by the scanner. A new iterative image reconstruction algorithm called Quantum Iterative Reconstruction (QIR)

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Methods

Conclusion