Ultra-high-field MRI in Neuroimaging: From Technical Innovation to Clinical Translation: A comprehensive review article.

Abstract

Ultra-high-field magnetic resonance imaging (MRI), particularly at 7 Tesla (7T) and beyond, has emerged as one of the most transformative developments in modern neuroimaging. The technology offers substantial gains in signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and spatial resolution, enabling unprecedented visualisation of cortical architecture, hippocampal subfields, white matter lesions, microvascular networks, and subtle tumor margins. These gains have supported an expanding body of work in epilepsy, multiple sclerosis, cerebrovascular disease, neuro-oncology, neurodegenerative disorders, and psychiatric research. At the same time, shifting from 3T to 7T introduces substantial technical and clinical challenges, including transmit radiofrequency (B1+) field inhomogeneity, higher specific absorption rate (SAR), stronger susceptibility artefacts, increased sensitivity to motion, and the need for specialised multi-channel hardware and advanced engineering expertise. This review summarises the physical basis of ultra-high-field neuroimaging, key pulse sequence adjustments and protocol adaptations, major clinical applications, and current barriers to widespread implementation. It also highlights future directions, including parallel transmission (pTx), deep-learning reconstruction, quantitative imaging, and the development of higher-field systems beyond 7T [1,2,3,4].