Deep-tissue anatomical imaging of mice using carbon nanotube fluorophores in the second near-infrared window.

Journal Article

Fluorescent imaging in the second near-infrared window (NIR II, 1-1.4 μm) holds much promise due to minimal autofluorescence and tissue scattering. Here, using well-functionalized biocompatible single-walled carbon nanotubes (SWNTs) as NIR II fluorescent imaging agents, we performed high-frame-rate video imaging of mice during intravenous injection of SWNTs and investigated the path of SWNTs through the mouse anatomy. We observed in real-time SWNT circulation through the lungs and kidneys several seconds postinjection, and spleen and liver at slightly later time points. Dynamic contrast-enhanced imaging through principal component analysis (PCA) was performed and found to greatly increase the anatomical resolution of organs as a function of time postinjection. Importantly, PCA was able to discriminate organs such as the pancreas, which could not be resolved from real-time raw images. Tissue phantom studies were performed to compare imaging in the NIR II region to the traditional NIR I biological transparency window (700-900 nm). Examination of the feature sizes of a common NIR I dye (indocyanine green) showed a more rapid loss of feature contrast and integrity with increasing feature depth as compared to SWNTs in the NIR II region. The effects of increased scattering in the NIR I versus NIR II region were confirmed by Monte Carlo simulation. In vivo fluorescence imaging in the NIR II region combined with PCA analysis may represent a powerful approach to high-resolution optical imaging through deep tissues, useful for a wide range of applications from biomedical research to disease diagnostics.

Full Text

Duke Authors

Cited Authors

  • Welsher, K; Sherlock, SP; Dai, H

Published Date

  • May 16, 2011

Published In

Volume / Issue

  • 108 / 22

Start / End Page

  • 8943 - 8948

PubMed ID

  • 21576494

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.1014501108

Language

  • eng