Simultaneous MR-microwave breast imaging: Initial phantom experiments.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Radiology

Background:

• Magnetic Resonance Imaging (MRI) is crucial for high-risk breast cancer screening, particularly for women with dense breasts.
• Gadolinium-based contrast agents enhance MRI sensitivity but pose potential health risks.
• There is a need for alternative breast MRI techniques that improve specificity without gadolinium.

Purpose of the Study:

• To develop and evaluate an integrated Microwave Imaging (MI) and MRI system for enhanced breast cancer detection.
• To combine the high resolution of MRI with the high specificity of MI using endogenous tissue properties.
• To demonstrate a novel MI system operating within an MRI scanner bore without disrupting image acquisition.

Main Methods:

• Simultaneous acquisition of MRI and microwave data within MRI scanner constraints.
• Utilized a coaxial antenna feedline system and a movable imaging tank with integrated breast coils for multi-planar views.
• Employed a soft-prior-based algorithm for 3D image reconstruction, directly incorporating MR spatial information.

Main Results:

• Successfully recovered spherical fibroglandular and tumor-equivalent tissue inclusions within adipose tissue at 900, 1100, and 1300 MHz.
• Microwave property distributions showed distinct gradients at tissue interfaces.
• Permittivity imaging accurately represented all tissue types; conductivity imaging was accurate for adipose and tumor tissues but less so for fibroglandular tissue.

Conclusions:

• This work presents the first 3D microwave images reconstructed inside an MRI scanner bore using MRI data as spatial priors.
• Logistical challenges of the integrated MR-MI system were successfully managed, yielding accurate phantom images.
• The multi-modality approach is validated and ready for future clinical application in patient examinations.