Multicolor spectral photon-counting computed tomography: in vivo dual contrast imaging with a high count rate scanner

David P Cormode,Ira Blevis,Franck Lavenne,Salim Si-Mohamed,Joelle Balegamire,Loic Boussel,Matthias Bartels,Philippe Douek,Michal Rokni,Daniel Bar-Ness,Pratap C Naha,Ewald Roessl,Monica Sigovan,Philippe Coulon

doi:10.1038/s41598-017-04659-9

Abstract

A new prototype spectral photon-counting computed tomography (SPCCT) based on a modified clinical CT system has been developed. SPCCT analysis of the energy composition of the transmitted x-ray spectrum potentially allows simultaneous dual contrast agent imaging, however, this has not yet been demonstrated with such a system. We investigated the feasibility of using this system to distinguish gold nanoparticles (AuNP) and an iodinated contrast agent. The contrast agents and calcium phosphate were imaged in phantoms. Conventional CT, gold K-edge, iodine and water images were produced and demonstrated accurate discrimination and quantification of gold and iodine concentrations in a phantom containing mixtures of the contrast agents. In vivo experiments were performed using New Zealand White rabbits at several times points after injections of AuNP and iodinated contrast agents. We found that the contrast material maps clearly differentiated the distributions of gold and iodine in the tissues allowing quantification of the contrast agents’ concentrations, which matched their expected pharmacokinetics. Furthermore, rapid, repetitive scanning was done, which allowed measurement of contrast agent kinetics with high temporal resolution. In conclusion, a clinical scale, high count rate SPCCT system is able to discriminate gold and iodine contrast media in different organs in vivo.

Highlights

ObjectivesThe purpose of this study was to investigate whether a small FOV prototype SPCCT scanner based on a modified clinical CT system (Fig. 1B) with high count rate performance was able to distinguish iodine and gold contrast media from endogenous tissues in a single scan
To the best of our knowledge, we have demonstrated for the first time the potential of the newly developed prototype spectral photon counting CT imaging system for qualitative and quantitative discrimination of two contrast agents in vivo, simultaneously over time, indicating the clinical impact of SPCCT in the field of “multicolor” imaging
This finding points to preclinical and clinical applications with various types of contrast agents to probe other biological processes and diseases, and for multi-phase imaging in a single scan

Summary

Objectives

The purpose of this study was to investigate whether a small FOV prototype SPCCT scanner based on a modified clinical CT system (Fig. 1B) with high count rate performance was able to distinguish iodine and gold contrast media from endogenous tissues in a single scan

Methods

Results

Discussion

Conclusion