Development of MRI phantom equivalent to human tissues for 3.0-T MRI

Area of Science:

• Medical Imaging
• Biophysics

Background:

• Magnetic Resonance Imaging (MRI) requires phantoms for calibration and quality assurance.
• Existing phantoms may not accurately replicate the complex relaxation times and conductivity of human tissues at higher field strengths.
• Developing a versatile phantom is crucial for advancing MRI research and clinical applications.

Purpose of the Study:

• To develop a novel 3.0-Tesla (3.0-T) MRI phantom, termed the CAGN-3.0T phantom.
• To achieve human-equivalent relaxation times (T1 and T2) and conductivity within the phantom.
• To create a tool for accurate MRI system performance evaluation.

Main Methods:

• The CAGN-3.0T phantom was formulated using carrageenan, agarose, Gadolinium chloride (GdCl3), Sodium chloride (NaCl), and Sodium azide (NaN3).
• Varying concentrations of agarose, GdCl3, and NaCl were used to modify T2, T1, and conductivity, respectively.
• T1 and T2 relaxation times and conductivity were measured using 3.0-T MRI.

Main Results:

• Empirical formulae were derived to correlate ingredient concentrations with T1, T2, and conductivity.
• The phantom's T1 values were independent of NaCl, while T2 values showed minimal impact.
• The developed formulae accurately describe the relationships between component concentrations and phantom properties.

Conclusions:

• The CAGN-3.0T phantom can simulate the relaxation times and conductivity of nearly all human tissues by adjusting ingredient concentrations.
• Achievable ranges include T1 (395–2601 ms), T2 (29–334 ms), and conductivity (0.27–1.26 S/m).
• The phantom possesses structural integrity for replicating anatomical regions like the torso and is easily customizable in shape.