Institute of Applied Acoustics, School of Physics and Information Technology, Shaanxi Normal University, Xi'an, China.
MOE Key Laboratory of Modern Teaching Technology, Shaanxi Normal University, Xi'an, China.
Ultrason Imaging. 2022 Nov;44(5-6):204-212. doi: 10.1177/01617346221116781. Epub 2022 Aug 11.
Photoacoustic (PA) imaging technology is of some value in medical diagnoses such as breast cancer detection, vasculature imaging, and surgery navigating. While as most imaging objects are bounded, the received RF signals consist of the direct-arrived signals (DAS) from the PA sources and the boundary-reflected signals (BRS). The undesired BRS will severely impair the quality during the image reconstruction. They will bring in many artifacts and confuse the actual shape and location of the PA sources. We improved the reconstruction procedure by removing the BRS before the regular reconstruction process to suppress those artifacts. To verify our proposed method, we compared the results of the conventional and optimized procedures experimentally. In terms of qualitative observation, the reconstructed images by the optimized procedure illustrate fewer artifacts and more accurate shapes of the PA sources. To quantitatively evaluate the traditional and the optimized imaging procedure, we calculated the Distribution Relative Error (DRE) between each experiment result and its standard drawing of the phantoms. For both phantoms and the ex-vivo sample, the DREs of reconstruction result by the optimized reconstruction procedure decrease significantly. The results suggest that the optimized reconstruction process can effectively suppress the reflection artifacts and improve the shape accuracy of the PA sources.
光声（PA）成像技术在医学诊断中具有一定的价值，如乳腺癌检测、血管成像和手术导航。由于大多数成像物体都是有界的，因此接收到的射频信号包括来自 PA 源的直达信号（DAS）和边界反射信号（BRS）。不希望的 BRS 在图像重建过程中会严重降低质量。它们会带来许多伪影，并混淆 PA 源的实际形状和位置。我们通过在常规重建过程之前去除 BRS 来改进重建过程，以抑制这些伪影。为了验证我们提出的方法，我们通过实验比较了常规和优化过程的结果。从定性观察的角度来看，通过优化过程重建的图像具有更少的伪影和更准确的 PA 源形状。为了定量评估传统和优化的成像过程，我们计算了每个实验结果与其标准图之间的分布相对误差（DRE）。对于两个体模和离体样本，优化重建过程的重建结果的 DRE 显著降低。结果表明，优化的重建过程可以有效地抑制反射伪影，提高 PA 源的形状精度。
