A Review of Enabling Technologies for Magnetic Particle Imaging

This paper offers a brief survey of Magnetic Particle Imaging (MPI) and its enabling technologies. MPI is an emerging molecular imaging modality that provides a superior alternative to other medical imaging methods such as magnetic resonance imaging (MRI) and X-Ray in some applications. MPI utilizes imaging concepts and hardware that are like MRI; however, its physics is different from that of MRI. MPI relies on measuring magnetic fields created by super-paramagnetic nanoparticles as tracers, offering a much higher contrast and sensitivity. Different from MRI, MPI can only measure and see the magnetized particles and not the tissue. MPI relieves the need for x-rays or harmful agents or positron emission tomography (PET) in many applications because it does not need ionizing radiation. The biocompatible iron oxide nanoparticles are used as tracers for in-vivo MPI measurements. This makes it possible to generate real-time in-vivo results from dynamic organs (e.g., a beating heart, blood flow in veins) allowing for producing 4D medical images (3D videos) of the dynamics of the internal organs, which will be indispensable in treatment planning and diagnosis of many serious diseases such as cancer, stroke, or cardiovascular ailments. Enabling MPI requires functionalities and technologies that are different from existing medical imaging and image processing techniques. We review some of the recent works on these technologies and point to the currently missing functionalities. For example, the conventional medical image analysis techniques are incapable of fully utilizing the hidden information in 4D data which could be produced by MPI.
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