Picomolar sensitivity MRI and photoacoustic imaging of cobalt nanoparticles

TLDR

Multimodality imaging, which combines complementary detection principles, has broad clinical applications and enhances diagnostic accuracy by enabling tracer particles to integrate multiple functionalities into a single delivery vehicle. The study investigates using combined MRI and photoacoustic tomography to detect picomolar concentrations of nanoparticles. The probe is a ferromagnetic cobalt core coated with gold, whose shape allows broad‑frequency optical absorption, enabling simultaneous MRI and PAT detection. The dual‑modality probe successfully detects trace nanoparticle concentrations in tissues, with MRI providing volumetric detection and PAT delivering edge detection.

Abstract

Multimodality imaging based on complementary detection principles has broad clinical applications and promises to improve the accuracy of medical diagnosis. This means that a tracer particle advantageously incorporates multiple functionalities into a single delivery vehicle. In the present work, we explore a unique combination of MRI and photoacoustic tomography (PAT) to detect picomolar concentrations of nanoparticles. The nanoconstruct consists of ferromagnetic (Co) particles coated with gold (Au) for biocompatibility and a unique shape that enables optical absorption over a broad range of frequencies. The end result is a dual-modality probe useful for the detection of trace amounts of nanoparticles in biological tissues, in which MRI provides volume detection, whereas PAT performs edge detection.