Portable Ultra-Low-Field MRI in Neurologic Diseases: Current Status and Potential in Clinical Practice, Research, and Trials.

Neurologic diseases are highly prevalent, and MRI plays a crucial role in their diagnosis, prognosis, and treatment monitoring. Conventional MRI at high magnetic field strength (≥1.5 tesla) is one of the most widely used modalities in clinical practice and a common outcome measure in clinical trials. Despite its importance and effectiveness, challenges, such as high cost, limited accessibility, and disease-related constraints, can hinder its widespread use. Recent advancements in portable ultra-low-field (<0.1 tesla) MRI technology offer potential solutions by enabling point-of-care brain imaging for neurologic diseases. However, the substantially lower magnetic field strength results in lower signal-to-noise ratio, reduced spatial resolution, and more limited imaging contrast, although ongoing computational approaches aim to mitigate some of these limitations. In this narrative review, we examine current evidence on applications of portable ultra-low-field MRI to neurologic disorders, discussing the technology's utility, limitations, and clinical implications. In addition, we highlight key open research questions and future opportunities for further integration of this emerging technology.