Radiation-force-based estimation of acoustic attenuation using harmonic motion imaging (HMI) in phantoms and in vitro livers before and after HIFU ablation.
Radiation-force-based estimation of acoustic attenuation using harmonic motion imaging (HMI) in phantoms and in vitro livers before and after HIFU ablation.
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DOI：
10.1088/0031-9155/60/19/7499
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发表时间：
2015-10-07
影响因子：
3.5
通讯作者：
Konofagou E
中科院分区：
文献类型：
--
作者：
Chen J;Hou GY;Marquet F;Han Y;Camarena F;Konofagou E
声衰减表示传播波通过生物组织的能量损失，并且在治疗和诊断超声应用中起着重要作用。声衰减的估计仍然具有挑战性，但对组织定征至关重要。在这项研究中，一个衰减估计的方法是使用谐波运动成像（HMI）的辐射力为基础的方法。通过以光栅扫描格式移动换能器来获取2D组织位移图。线性回归模型应用于HMI位移在不同深度的对数，以估计声衰减。测试了具有已知衰减的市售体模（n=5）和体外犬肝脏（n=3），以及体外犬肝脏（n=5）中的HIFU损伤。结果表明，从体模获得的衰减与制造商报告的独立获得的值具有良好的相关性（R2=0.976），估计误差（与独立测量的值相比）在15- 35%的范围内变化。在离体犬肝中的估计衰减等于0.32± 0.03dB/cm/MHz，这与现有文献很好地一致。HIFU损伤组织的衰减（0.58± 0.06dB/cm/MHz）高于正常组织，与文献报道的结果一致。所提出的方法的未来潜在应用包括估计热消融前后的病理组织中的衰减。
Acoustic attenuation represents the energy loss of the propagating wave through biological tissues and plays a significant role in both therapeutic and diagnostic ultrasound applications. Estimation of acoustic attenuation remains challenging but critical for tissue characterization. In this study, an attenuation estimation approach was developed using the radiation-force-based method of Harmonic Motion Imaging (HMI). 2D tissue displacement maps were acquired by moving the transducer in a raster-scan format. A linear regression model was applied on the logarithm of the HMI displacements at different depths in order to estimate the acoustic attenuation. Commercially available phantoms with known attenuations (n=5) and in vitro canine livers (n=3) were tested, as well as HIFU lesions in in vitro canine livers (n=5). Results demonstrated that attenuations obtained from the phantoms showed a good correlation (R2=0.976) with the independently obtained values reported by the manufacturer with an estimation error (compared to the values independently measured) varying within the range of 15-35%. The estimated attenuation in the in vitro canine livers was equal to 0.32±0.03 dB/cm/MHz, which is in good agreement with the existing literature. The attenuation in HIFU lesions was found to be higher (0.58±0.06 dB/cm/MHz) than that in normal tissues, also in agreement with the results from previous publications. Future potential applications of the proposed method include estimation of attenuation in pathological tissues before and after thermal ablation.