Magnetic nanoparticle temperature imaging with a scanning magnetic particle spectrometer

Non-invasive and in vivo temperature imaging plays a significant role in disease diagnostics and therapy. This paper proposes a method of magnetic nanoparticle (MNP) temperature imaging with a scanning magnetic particle spectrometer (SMPS), which has great potential for non-invasive and in vivo temperature imaging beneath the surface of an object. The SMPS system, consisting of a mechanical scanner and a magnetic particle spectrometer (MPS), is built to measure the spatial distributions of the fundamental f(0) and 3f(0) harmonics of a MNP sample. A reconstruction method based on the point spread function, defined by the sensitivity profile of the pickup coil, is investigated to visualize the spatial distributions of MNP concentration and temperature. Experiments on a phantom with different temperature profiles are performed, which demonstrate the feasibility of the proposed method for MNP temperature imaging with a spatial resolution of about 3.5 mm. The SMPS is a low-cost and versatile setup for MNP concentration and temperature imaging, which has great potential for disease diagnostics and therapy.