摘要
Magnetic resonance imaging(MRI),as a noninvasive and powerful method in modern diagnostics,has been advancing in leaps and bounds.Conventional methods to improve MRI based on increasing the static magnetic field strength are restricted by safety concerns,cost issues,and the impact on patient experience;as such,innovative approaches are required.It has been suggested that metamaterials featuring subwavelength unit cells can be used to take full control of electromagnetic waves and redistribute electromagnetic fields,achieve abundant counterintuitive phenomena,and construct versatile devices.Recently,metamaterials with exotic effective electromagnetic parameters,peculiar dispersion relations,or tailored field distribution of resonant modes have shown promising capabilities in MRI.Herein,we outline the principle of the MRI process,review recent advances in enhancing MRI by employing the unique physical mechanisms of metamaterials,and demystify ways in which metamaterial designs could improve MRI,such as by enhancing the imaging quality,reducing the scanning time,alleviating field inhomogeneities,and increasing patient safety.We conclude by providing our vision for the future of improving MRI with metamaterials.
基金
supported by the National Key R&D Program of China(Grant Nos.2021YFA1400602 and 2023YFA1407600)
the National Natural Science Foundation of China(Grant Nos.91850206,12374294,and 12004284)
the Chenguang Program of Shanghai(Grant No.21CGA22).
