# Enabling magnetic resonance imaging of hollow-core microstructured optical fibers via nanocomposite coating

## TL;DR

This paper introduces a nanocomposite coating technique that enables MRI visibility of hollow-core microstructured optical fibers, facilitating combined optical and MRI bioimaging for minimally invasive diagnostics.

## Contribution

The study presents a novel Layer-by-Layer assembly method to make optical fibers MRI-visible by incorporating magnetite nanoparticles, combining optical transmission shifts with MRI contrast.

## Key findings

- Magnetite nanoparticle coating renders fibers MRI-visible.
- Transmission spectra of fibers shift up to 60 nm with coating.
- High-quality MRI contrast achieved for coated fibers.

## Abstract

Optical fibers are widely used in bioimaging systems as flexible endoscopes capable of low-invasive penetration inside hollow tissue cavities. Here, we report on the technique which allows magnetic resonance imaging (MRI) of hollow-core microstructured fibers (HC-MFs), paving the way for combing MRI and optical bioimaging. Our approach is based on Layer-by-Layer assembly of oppositely charged polyelectrolytes and magnetite nanoparticles on the inner core surface of HC-MFs. Incorporation of magnetite nanoparticles into polyelectrolyte layers renders HC-MFs visible for MRI and induces the red-shift in their transmission spectra. Specifically, the transmission shifts up to 60 nm have been revealed for the several-layers composite coating along with the high-quality contrast of HC-MFs in MRI scans. Our results shed light on marrying fiber-based endoscopy with MRI that opens novel possibilities for minimally invasive clinical diagnostics and surgical procedures in vivo.

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Source: https://tomesphere.com/paper/1903.03376