Development of a focused-X-ray luminescence tomography (FXLT) system

TL;DR

This paper introduces a novel FXLT system utilizing a superfine focused X-ray beam, achieving sub-150 micrometer spatial resolution and high molecular sensitivity, addressing key challenges in deep tissue biophotonics imaging.

Contribution

The paper presents the design, implementation, and evaluation of a focused-X-ray luminescence tomography system with improved spatial resolution and sensitivity for deep tissue imaging.

Findings

Spatial resolution better than 150 micrometers

Molecular sensitivity of approximately 2-5 micromolar

Validated system performance through simulations and experiments

Abstract

Biophotonics is an active research area in molecular imaging, genetic diagnosis and prognosis, with direct applicability in precision medicine. However, long-standing challenges of biophotonics are well known due to low signal-to-noise ratio and poor image quality, mainly due to strong optical scattering especially in deep tissues. Recently, X-ray luminescence computed tomography (XLCT) has emerged as a hybrid molecular imaging modality and shown great promises in overcoming the optical scattering in deep tissues. However, its high spatial resolution capacity has not been fully implemented yet. In this paper, with a superfine focused X-ray beam we design a focused-X-ray luminescence tomography (FXLT) system for spatial resolution better than 150 micrometers and molecular sensitivity of 2 micromolar. First, we describe our system design. Then, we demonstrate that the molecular sensitivity of FXLT is about 5 micromolar considering the emitted visible photons from background. Furthermore, we analyze the measurement time per scan from measured photons numbers with a fiber bundle-PMT setup, report numerical and experimental results. Finally, we specify the imaging system performance based on numerical simulations and physical measurements.