Purpose

The reliable transcranial imaging of brain inner structures for diagnostic purposes is deemed crucial owing to the decisive importance and contribution of the brain in human life. The purpose of this paper is to investigate the potential application of medical ultrasounds to transcranial imaging using advanced techniques, such as the total focussing method.

Design/methodology/approach

Initially, the fundamental details of the total focussing method are presented, while the skull properties, such as the increased acoustic velocity and scattering, are thoroughly examined. Although, these skull characteristics constitute the main drawback of typical transcranial ultrasonic propagation algorithms, they are exploited to focus the acoustic waves towards the brain. To this goal, a virtual source is designed, considering the wave refraction, to efficiently correct the reconstructed brain image. Finally, the verification of the novel method is conducted through numerical simulations of various realistic setups.

Findings

The theoretically designed virtual source resembles a focussed sensor; therefore, the directivity increment, owing to the propagation through the skull, is confirmed. Moreover, numerical simulations of real-world scenarios indicate that the typical artifacts of the conventional total focussing method are fully overcome because of the increased directivity of the proposed technique, while the reconstructed image is efficiently corrected when the proposed virtual source is used.

Originality/value

A new systematic methodology along with the design of a flexible virtual source is developed in this paper for the reliable and precise transcranial ultrasonic image reconstruction of the brain. Despite the slight degradation owing to the skull scattering, the combined application of the total focussing method and the featured virtual source can successfully detect arbitrary anomalies in the brain that cannot be spotted by conventional techniques.

中文翻译：

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经颅超声传播和利用颅骨的聚焦效应增强脑成像

目的

由于大脑在人类生活中具有决定性的重要性和贡献，因此出于诊断目的对大脑内部结构进行可靠的经颅成像至关重要。本文的目的是研究使用先进技术（例如全聚焦法）的医学超声在经颅成像中的潜在应用。

设计/方法/方法

最初，介绍了总聚焦方法的基本细节，同时彻底检查了头骨的特性，例如声速和散射的增加。尽管这些颅骨特征构成了典型的经颅超声传播算法的主要缺点，但它们被利用来将声波聚焦到大脑。为此，设计了一种虚拟源，考虑了波的折射，可以有效地校正重建的大脑图像。最后，通过各种实际设置的数值模拟对新方法进行了验证。

发现

理论上设计的虚拟源类似于聚焦传感器。因此，由于通过头骨的传播，方向性增加得以确认。此外，真实世界场景的数值模拟表明，由于所提出技术的方向性增加，可以完全克服常规总聚焦方法的典型伪像，而当使用所提出的虚拟源时，可以有效地校正重建图像。

创意/价值

本文开发了一种新的系统方法和灵活的虚拟源设计，可对大脑进行可靠而精确的经颅超声图像重建。尽管由于颅骨散射而导致的轻微退化，但总聚焦方法和特色虚拟源的组合应用可以成功检测到大脑中常规技术无法发现的任意异常。