# Life time imaging with pulsed x-ray based x-ray luminescence computed tomography

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, MERCED · 2021 · $63,025

## Abstract

SUMMARY
Lifetime imaging, such as fluorescence lifetime imaging, is able to provide extensive physiological information
in cells or tissues. Fluorescence lifetime imaging is mainly applied to superficial targets or objects that can be
reached by an optical guidance. For deep targets, fluorescence lifetime imaging suffers low spatial resolution and
poor image quality due to strong optical scattering. In this proposal, we will develop a unique, novel biophotonics
imaging modality, time domain x-ray luminescence computed tomography (tdXLCT), which combines the spatial
resolution of x-ray imaging with the high detection sensitivity of optical imaging. The tdXLCT will be a new
approach to explore lifetime imaging in deep targets. In the tdXLCT, an ultrafine pulsed x-ray beam will excite
nanophosphors in deep targets and the emitted photons will be measured with a sensitive photomultiplier tube
module.
 In this administrative supplement proposal, the supported graduate student will build a lifetime
measurement system for samples, evaluate the lifetime in different environments, as well as synthesize and
characterize x-ray excitable nanophosphors with better emission efficiency. Furthermore, he will build, for the
first time, a tdXLCT system and evaluate its performance with phantom imaging experiments.
 The proposed tdXLCT will explore the applicability of x-ray as a molecular imaging tool and as a means
to obtain information on the physiochemical characteristics of microenvironments in deep tissues (e.g.
oxygenation level). The proposed tdXLCT will be of interest to many biological researchers in the fields of
nanomedicine and cancer therapy because it has the potential to overcome limitations associated with
radiolabeling (limited half-life) and fluorescence tagging (poor spatial resolution at depths).
 Relationship to the parent grant: This proposal is closely related to the parent grant. Both of them explore
the application of x-ray luminescence imaging. However, the parent grant aims to explore the high spatial
resolution XLCT imaging in the continue wave (CW) domain. This proposal aims to explore the applications of
pulsed x-ray luminescence in time domain. This proposal will also utilize the synthesized nanoparticles from the
parent grant.

## Key facts

- **NIH application ID:** 10307274
- **Project number:** 3R01EB026646-04S1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, MERCED
- **Principal Investigator:** Changqing Li
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $63,025
- **Award type:** 3
- **Project period:** 2018-07-01 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10307274

## Citation

> US National Institutes of Health, RePORTER application 10307274, Life time imaging with pulsed x-ray based x-ray luminescence computed tomography (3R01EB026646-04S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10307274. Licensed CC0.

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