Speaker
Description
The pursuit of ultrahigh magnetic fields is a key research direction in MRI, offering high signal-to-noise ratio (SNR), high resolution, and advanced imaging methodologies. However, ultrahigh-field MRI systems, such as 7T human MRI, are extremely costly, often around 10 million US dollars, making them unaffordable for many researchers. Therefore, there is a high demand for developing ultrahigh-field MRI systems that are lower in cost while retaining basic functionality. This work presents a 7T MRI superconducting magnet with a clear bore size 54mm that is aimed at micro-imaging, which is affordable, lightweight, and easily maintained using cryogen-free technology. The magnet weight is only 304 kg, with dimensions of 58 cm in length and 65 cm in height, allowing for flexible installation in the lab. The 5Gauss line is tightly surrounded around the magnet with ±0.7m at the axial direction and ±0.5m at the radial direction, and the decay rate of the magnetic field is only 0.01ppm/h. The initial magnetic field homogeneity over a 30mm diameter of spherical volume (DSV) is 107.42ppm, and it is highly improved to 11.12ppm after superconducting shimming with the shim coils integrated into the cryogenic system. Initial imaging generates high-quality images with a resolution of 48μm, which demonstrated the strong potential of the magnet scheme on details imaging. The ultrahigh-field, cryogen-free, portable, high-resolution MRI system will be an economical tool for researchers engaged in ultrahigh-field related studies.
