Low-intensity focused ultrasound for human neuromodulation

Low-intensity focused ultrasound (LIFU) is a potentially transformative form of human non-invasive neuromodulation that provides millimetre-sized focal volumes combined with adjustable focal lengths that can target small and deep human brain circuitry. This Primer is intended for those looking to conduct LIFU studies in humans and outlines several important considerations, findings and limitations of focused ultrasound for human neuromodulation. The reader is introduced to the transducer and how ultrasound energy propagates into the human brain with considerations and limitations for doing this effectively. The potential effect of parameters and delivery of LIFU is discussed including mechanisms, exposure and safety. Highlights of findings from LIFU applications in healthy and clinical populations, as well as select in vitro and animal work, are provided to help the reader understand the current state of the field and the outlook of LIFU as a scientific and clinical tool.