Vasile Bogdan Neculaes

Multisource X-Ray and CT: Lessons Learned and Future Outlook

Distributed X-ray sources open the way to innovative system concepts in X-ray and computed tomography. They offer promising opportunities in terms of system performance, but they pose unique challenges in terms of source and system technologies. Several academic and industrial teams have proposed a variety of concepts and developed some unique prototypes. We present a broad review of multisource systems. We also discuss X-ray source components and challenges. We close with our perspective on the future prospects of multisource imaging.

Applications of phosphorescent materials for in-vivo imaging of brain structure and function

A number of approaches have been developed for in-vivo imaging of neural function at the time scale of action potentials and at the spatial resolution of individual neurons. Remarkable results have been obtained with optogenetics, although the need for genetic modification is an important limitation of these approaches. Similarly, voltage and ion-sensitive dyes allow for optical imaging of action potentials but toxicity remains a problem. Additionally, optical techniques are often only able to be used up to a limited depth. Our preliminary work has shown that nanoparticles of common phosphorescent materials, believed to be generally non-toxic, specifically lutetium oxide and strontium aluminate, can be utilized for cellular imaging, for tomographic imaging, and that the particles can be designed to adhere to neurons. Additionally, lutetium oxide has been shown to be highly X-ray luminescent, potentially allowing for imaging deep within the brain, if the particles can be targeted properly. In ex vivo experiments, we have shown that the phosphorescence of strontium aluminate particles is significantly affected by electric fields similar in strength to those found in the vicinity of the cellular membrane of a neuron. This phenomenon is consistent with early published reports in the electroluminescence literature, namely the Gudden-Pohl effect. We will show results of the ex vivo imaging and dynamic electrical stimulation experiments. We will also show some preliminary ex vivo cell culture results, and will describe plans for future research, focusing on potential in both cell cultures and in vivo for animal models.