Coloring ultrasensitive MRI with tunable metal-organic frameworks

Area of Science:

• Medical Imaging
• Materials Science
• Chemical Physics

Background:

• Magnetic resonance imaging (MRI) has limited sensitivity for low-abundance molecules.
• Hyperpolarized 129Xe MRI (ultrasensitive MRI) offers over 10,000-fold signal enhancement.
• Visualizing complex mixtures with ultrasensitive MRI is challenging due to difficulties in xenon atom capture.

Purpose of the Study:

• To develop a method for visualizing complex mixtures using ultrasensitive MRI.
• To utilize metal-organic frameworks (MOFs) as tunable nanoporous hosts for xenon.
• To overcome limitations in current ultrasensitive, multiplexed MRI techniques.

Main Methods:

• Metal-organic frameworks (MOFs) were designed as nanoporous hosts for 129Xe atoms.
• Spectroscopic signals of 129Xe within different MOFs were analyzed.
• The influence of MOF pore size, structure, and composition on xenon interaction was investigated.

Main Results:

• 129Xe in different MOFs produced widely dispersed spectroscopic signals, allowing for distinct visualization.
• MOF pore size was found to control the xenon exchange rate.
• MOF geometric structure and elemental composition affected the local charge experienced by xenon.

Conclusions:

• Metal-organic frameworks enable the differentiation of complex mixtures in ultrasensitive MRI through distinct spectral colors.
• MOFs provide suitable cavities for xenon, overcoming previous obstacles in ultrasensitive, multiplexed MRI.
• This approach advances the capability of ultrasensitive MRI for analyzing complex chemical environments.