Using linear array transducers in combination with state-of-the-art multichannel electronics allows to perform optoacoustic imaging with frame rates only limited by the laser pulse repetition frequency and the acoustic time of flight. However, characteristic image artefacts resulting from the limited view and a lower SNR when compared to systems based on single-element focused transducers represent a burden for the clinical acceptance of the technology. In this paper, we present a new method for the improvement of image quality based on the analysis of the signal amplitudes along summation curves during the delay-and-sum beamforming process (DAS). The algorithm compares amplitude distributions along wave fronts with theoretical patterns from optoacoustic point sources. The method was validated on simulated and experimental phantom as well as in-vivo data. An improvement of the lateral resolution by more than a factor of two when comparing conventional DAS and our approach could be shown (numeric and experimental phantom data). For instance, on experimental data from a wire phantom, a PSF in the range of 0.18–0.22 mm was obtained with our approach against 0.48 mm for standard DAS. Furthermore, the SNR of a subcutaneous vessel 2.5 mm below the skin surface was improved by about 30 dB when compared to standard DAS.

结合使用线性阵列换能器和最新的多通道电子设备，可以执行光声成像，其帧速率仅受激光脉冲重复频率和声波飞行时间限制。然而，与基于单元素聚焦换能器的系统相比，由有限的视野和较低的SNR产生的特征性图像伪像代表了该技术在临床上的接受负担。在本文中，我们基于延迟和求和波束形成过程（DAS）沿求和曲线的信号幅度分析，提出了一种提高图像质量的新方法。该算法将沿波前的振幅分布与来自光声点源的理论模式进行比较。该方法已在模拟和实验模型以及体内数据。与传统的DAS和我们的方法相比，横向分辨率提高了两倍以上（数字和实验幻像数据）。例如，根据线模的实验数据，我们的方法获得的PSF在0.18-0.22 mm范围内，而标准DAS则为0.48 mm。此外，与标准DAS相比，皮肤表面以下2.5 mm的皮下血管的SNR提高了约30 dB。