Magnetic resonance imaging (MRI) is a widely used tool to generate detailed images of diverse body parts including organs, soft tissue, and bone. Quantitative parametric MRI enables comparison of images across multiple sites, greater objectivity, and application of sophisticated analysis techniques such as artificial intelligence and deep learning. A factor currently limiting widespread utilization of parametric MRI is the development of robust, reliable calibration standards (aka “phantoms”). Without proper calibration, MRI data cannot be easily compared across different timepoints and at different institutions.
Diffusion MRI (dMRI) measures the movement of water molecules in biological tissues and has been applied in imaging brain diseases (e.g., Alzheimer’s Disease, Multiple Sclerosis). Diffusion tensor imaging (DTI) is one dMRI technique that has been utilized by researchers but is not well-suited to clinical application. Diffusion kurtosis imaging (DKI) is better for clinical application but appropriate calibration standards have been difficult to develop. Past efforts based on perishable goods are not sufficiently durable and approaches based on microbeads have not been able to mimic biologically relevant kurtosis values. This limitation is significant as each body tissue exhibits distinct diffusion properties and thus needs a unique standard for calibration.
Tunable MRI Phantoms for DKI
The proposed technology is tool that can be used to calibrate DKI measurements. This tool or phantom contains a liquid mixture which is designed to mimic human biological tissue. Importantly, this mixture is derived from a combination of three stable, safe, cost-effective, and readily available materials. By modulating the amount of each component, the phantom can be tuned to uniquely mimic different organs at biologically relevant values for apparent diffusion and kurtosis coefficients. This tool will facilitate a standardized approach for calibration of DKI measurements and will help expand the use of this powerful imaging tool.
· Calibration of MRI instruments for diffusion kurtosis imaging (DKI), a diffusion MRI technique
· Quantitative, parametric imaging of brain, head and neck, and prostrate, among others
· Potentially applicable to imaging of a wide variety of cancer types
· Adjustable to mimic different tissues
· Displays clinically relevant diffusion and kurtosis coefficients with excellent signal-to-noise
· Comprised of stable, safe, cost-effective and readily available liquids