Emerging non-cancer applications of therapeutic ultrasound

Abstract

Ultrasound therapy has been investigated for over half a century. Ultrasound can act on tissue through a variety of mechanisms, including thermal, shockwave and cavitation mechanisms, and through these can elicit different responses. Ultrasound therapy can provide a non-invasive or minimally invasive treatment option, and ultrasound technology has advanced to the point where devices can be developed to investigate a wide range of applications. This review focuses on non-cancer clinical applications of therapeutic ultrasound, with an emphasis on treatments that have recently reached clinical investigations, and preclinical research programmes that have great potential to impact patient care.

Keywords: Clinical; non-oncologic applications of hyperthermia; ultrasound.

Figure 1

Illustration of different treatment types. From left to right: thermal, shockwave and cavitation-mediated.

Figure 2

Some applications of therapeutic ultrasound.

Figure 3

(Left) Magnitude MRI image showing a steerable, MR-compatible endovascular HIFU catheter in an ex vivo porcine heart (white ellipse indicates catheter tip). (Right) MR thermometry image in a plane normal to the catheter tip showing the temperature rise in the heart wall. Courtesy of M. Carias.

Figure 4

(Top) Treatment setup for ultrasound therapy using a large aperture array. (Bottom) Baseline axial T₁-weighted MRI of a rabbit brain, and corresponding post-FUS, contrast-enhanced image showing enhancement indicating disruption of the BBB at the treated location (arrow).