In this study, we developed microwave-induced thermoacoustic endoscopy (TAE), which employs a high-repetition-rate pulsed microwave generator for external excitation and a side-view focused ultrasound transducer for internal acoustic detection. The system yields a lateral resolution of 1.5 mm and an axial resolution of 0.35 mm. The penetration depths of saline-containing tube (5% NaCl) and tumor lesions in biological tissues are 9 and 6 cm under current experimental conditions, respectively. To improve the signal-to-noise ratio (SNR) of the reconstructed image and eliminate the off-focus distortion of the transducer, we applied the synthetic aperture focusing technique (SAFT) and coherence weighting factor into the reconstruction algorithm. Additionally, we carried out in vivo rat experiments to evaluate clinical feasibility of this technique. We could clearly distinguish multiple tumor lesions embedded inside the rat abdomen from the surrounding normal tissues.

中文翻译：

---

热声内窥镜

在这项研究中，我们开发了微波感应热声内窥镜（TAE），该技术使用高重复频率脉冲微波发生器进行外部激励，并使用侧视聚焦超声换能器进行内部声学检测。该系统产生的横向分辨率为1.5毫米，轴向分辨率为0.35毫米。在目前的实验条件下，含盐水的试管（5％NaCl）和肿瘤在生物组织中的穿透深度分别为9 cm和6 cm。为了提高重建图像的信噪比（SNR）并消除换能器的离焦失真，我们将合成孔径聚焦技术（SAFT）和相干加权因子应用于重建算法中。此外，我们在体内进行了大鼠实验以评估该技术的临床可行性。我们可以从周围正常组织中清楚地区分大鼠腹部内嵌的多个肿瘤病变。