Shine and darkle the blood vessels: Multiparameter hypersensitive MR angiography for diagnosis of panvascular diseases.

Abstract

Magnetic resonance angiography (MRA) is pivotal for diagnosing panvascular diseases. However, single-modality MRA falls short in diagnosing diverse vascular abnormalities. Thus, contrast agents combining <i>T</i>₁ and <i>T</i>₂ effects are sought for multiparameter MRA with clinical promise, yet achieving a balance in <i>T</i>₁ and <i>T</i>₂ contrast enhancement effects remains a scientific challenge. Herein, we developed a hypersensitive multiparameter MRA strategy using dual-modality NaGdF₄ nanoparticles. Because of the longer tumbling time (τ_R), NaGdF₄ nanoparticles can improve the longitudinal relaxivity (<i>r</i>₁), brightening vessels in <i>T</i>₁-weighted sequences. Simultaneously, the regular arrangement of Gd³⁺ in the crystal induces magnetic anisotropy, creating local static magnetic field heterogeneity and generating negative signals in <i>T</i>₂-weighted sequences. Consequently, the efficacy of NaGdF₄-enhanced high-resolution multiparameter MRA has been validated in diagnosing ischemic stroke and Alzheimer's disease in rodent models. In addition, the dual-contrast imaging has been realized on swine with a clinical 3.0-T magnetic resonance imaging scanner, highly emphasizing the clinical translation prospect.