Magnetic particle imaging (MPI) provides quantitative maps of magnetic nanoparticle concentration and is well suited for monitoring magnetically induced hyperthermia and drug release. Building on the frequency-mixing, narrowband MPI platform previously presented at IWMPI 2024, we now focus on a reconstruction framework based on a block Alternating Direction Method of Multipliers (block-ADMM) operator formulation for efficient multi-contrast image recovery. The system employs dual-frequency excitation around 280 kHz and < 1 kHz, allowing simultaneous heating and imaging with excellent spectral separation and sensitivity. The proposed algorithm jointly inverts multiple spectral components centered at 2?fHF ± N?fLF that share a common nanoparticle distribution while exploiting their complementary spatial responses. This operator-based formulation enables near real-time reconstruction with improved resolution and noise robustness. First experimental results demonstrate temperature-dependent contrast formation, establishing a foundation for potentially quantitative MPI thermometry and feedback-controlled drug release.
Viereck et al. (Mon,) studied this question.