Development of a tissue-equivalent MRI phantom using carrageenan gel

Area of Science:

• Biomedical Engineering
• Magnetic Resonance Imaging
• Materials Science

Background:

• Developing accurate tissue-equivalent phantoms is crucial for Magnetic Resonance Imaging (MRI) calibration and research.
• Existing phantoms often lack the ability to precisely mimic the diverse relaxation properties of biological tissues.
• Carrageenan gel presents a promising material for creating robust and versatile MRI phantoms.

Purpose of the Study:

• To develop a novel tissue-equivalent MRI phantom using carrageenan gel.
• To achieve a wide range of tunable T(1) and T(2) relaxation times within the phantom.
• To establish a method for creating phantoms with arbitrary combinations of relaxation times for various human tissues.

Main Methods:

• Carrageenan gel was used as the base material for phantom fabrication.
• Gadolinium (III) chloride (GdCl(3)) was incorporated as a T(1) relaxation time modifier.
• Agarose was added as a T(2) relaxation time modifier.
• Relaxation times (T(1) and T(2)) were measured using 1.5-T clinical MRI equipment across varying concentrations of GdCl(3) and agarose.

Main Results:

• The developed carrageenan-based phantom demonstrated tunable T(1) values ranging from 202 to 1904 ms and T(2) values from 38 to 423 ms.
• The achieved range of relaxation times effectively covers those found in all types of human tissues.
• Empirical formulas were derived to accurately correlate modifier concentrations (GdCl(3) and agarose) with desired relaxation times.

Conclusions:

• The carrageenan gel phantom provides a versatile platform for creating tissue-equivalent MRI phantoms with precisely controlled relaxation properties.
• The ability to independently adjust T(1) and T(2) relaxation times enables the fabrication of phantoms that accurately simulate diverse human tissues.
• This technology facilitates the development of advanced MRI applications, phantom-based research, and quality assurance protocols.