High-intensity therapeutic ultrasound: metrological requirements versus clinical usage

Abstract

High-intensity therapeutic ultrasound (HITU) is an appealing non-invasive, non-ionizing therapeutic modality with a wide range of tissue interactions ranging from transient permeabilization of cell membranes to thermal ablation. The ability to guide and monitor the treatment with an associated ultrasonic or magnetic resonance imaging device has resulted in a dramatic rise in the clinical use of therapeutic ultrasound in the past two decades. Nevertheless, the range of clinical applications and the number of patients treated has grown at a much higher pace than the definition of standards. In this paper the metrological requirements of the therapeutic beams are reviewed and are compared with the current clinical use of image-guided HITU mostly based on a practical approach. Liver therapy, a particularly challenging clinical application, is discussed to highlight the differences between some complex clinical situations and the experimental conditions of the metrological characterization of ultrasonic transducers.

Impact of Shock-Induced Lipid Nanobubble Collapse on a Phospholipid Membrane

“…As an important and widely used technique, ultrasound has been increasingly utilized in biomedical fields, such as ultrasonic imaging and hyperthermia. − Nano- or microbubbles can serve as effective contrast agents to enhance the resolution of ultrasonic images. − In addition, ultrasound in combination with nano- or microbubbles has been used to mediate drug or gene delivery. − Ultrasound can enhance the uptake of molecules by increasing membrane permeability and generating temporary pores in membranes, which is defined as “sonoporation”. As reported previously, ultrasound intensity determines the mechanisms for bubble-induced sonoporation .…”

Tolerability and Feasibility of X-ray Guided Non-Invasive Ablation of the Medial Branch Nerve with Focused Ultrasound: Preliminary Proof of Concept in a Pre-clinical Model

“…The concentration of energy generates bio-effects precisely in the targeted area while sparing near and far-field tissue. For thermal ablation, coagulative necrosis occurs at the target (Aubry 2012).…”

Thin-film resistance temperature detector array for the measurement of temperature distribution inside a phantom

“…Compared to other non-invasive treatment methods, HIFU is a radiation-free and inexpensive method that can be repeated without exclusion of other treatment options [5]. To maximize the efficiency of HIFU therapy, it is important to monitor the temperature distribution around the target tissue [6][7][8][9]. Thermometry based on MR (magnetic resonance) and US (ultrasound) has been adopted for the real-time measurement of the temperature distribution during HIFU therapy.…”