High-intensity focused ultrasound is a non-invasive modality for thermal ablation of tissues through locally increased temperature. Thermal lesions can be monitored by elastography, following the changes in the elastic properties of the tissue as reflected by the shear-wave velocity. Most studies on ultrasound elastography use shear waves created by acoustic radiation force. However, in the human body, the natural noise resulting from cardiac activity or arterial pulsatility can be used to characterize elasticity through noise-correlation techniques, in the method known as passive elastography. The objective of this study was to investigate the feasibility of monitoring high-intensity ultrasound treatments of liver tissue using passive elastography. Bovine livers were heated to 80°C using a high-intensity planar transducer and imaged with a high-frame-rate ultrasound imaging device. The dynamics of lesion formation are captured through tissue stiffening and lesion expansion.

高强度聚焦超声是一种通过局部升高温度对组织进行热消融的非侵入性方式。根据剪切波速度所反映的组织弹性特性的变化，可以通过弹性成像来监测热损伤。大多数关于超声弹性成像的研究使用由声辐射力产生的剪切波。然而，在人体中，由心脏活动或动脉搏动引起的自然噪声可用于通过噪声相关技术（称为被动弹性成像的方法）来表征弹性。本研究的目的是调查使用被动弹性成像监测肝组织高强度超声治疗的可行性。使用高强度平面换能器将牛肝脏加热至 80°C，并使用高帧率超声成像设备进行成像。病变形成的动力学是通过组织硬化和病变扩张来捕捉的。