CST uses 3D electromagnetic simulation to test MRI system designs

MRI is a fundamental part of modern diagnostic imaging. With MRI, structures inside the body, even those made of soft tissue, can be imaged relatively quickly at a good resolution. However, the machinery needed to produce these images is complex. For reasonable image quality, the fields inside the scanner should be very homogeneous in the area of interest, which means that the magnets and coils need to be carefully designed to give the right field distribution. One way of testing the field distribution is to use prototypes. Unfortunately, MRI scanners are filled with large, precision-made components, which make building multiple prototypes difficult and expensive.

Simulation offers a much cheaper and faster way to test a design than repeatedly creating and testing new prototype coils and making incremental changes. As well as being a very flexible and fast approach for testing the properties of a design, it gives additional insight into the functional mechanisms of the system, allowing automatic optimization and tuning schemes. Alongside time and budgetary considerations, safety also has to be taken into account. Although MRI is usually thought of as safe by comparison to X-rays and CT scans, it can pose its own risks to the patient. During an MRI scan, the patient is subjected to significant RF fields, typically with frequencies on the order of hundreds of megahertz. These fields deposit energy in the body, and this causes heating. If the energy absorbed by the body exceeds the safety limits, significant damage can be done to tissues.

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