Early stage cancer detection technologies can provide functional information and potentially decrease the mortality rate caused by cervical cancer. In our previous work, a miniaturized ultrasound and photoacoustic endoscopic system has been developed to image the cervical tissue through the cervical canal to fulfills the need for a safe, low-cost, and high-resolution functional diagnostic system. However, the miniaturized size of endoscope and American National Standards Institute safety limits cause constraints of using high-intensity illumination during imaging. In addition, the strong light scattering of tissues limits the light penetration depth. Fortunately, the cervix anatomy allows for the delivery of additional light from the ectocervix by using an external illumination system. Here we propose a dual, co-planar illumination system, which can provide adequate illumination to the cervical tissue via combined internal and external light delivery strategies. Therefore, an increase in the area of light-tissue interaction allows us to raise the laser light energy while keeping fluence under safety limits. Thus, a reliable PA imaging can be obtained for the whole cervical tissue thickness. The system performance was tested using a Monte Carlo simulation, and laser-light fluence was calculated and compared at different depths within a simulated cervical-tissue model. The results indicated a higher and more uniform fluence in the Monte Carlo simulations. In addition, the photoacoustic imaging of the proposed system was evaluated by two cervical tissue-mimicking phantoms with human blood and graphite rods as inclusions inside it. In accordance with the simulations, the phantom study revealed a more reliable photoacoustic signal for the entire depth of the phantoms with an improved contrast to noise ratio and signal to noise ratio, and a higher coverage ratio of the imaging field of view. In summary, the dual-mode illumination system can provide more realistic information of inclusions within the tissue while considering safety limits, which can lead to more accuracy in biomarker detection for cervical cancer diagnostics.

中文翻译：

---

用于宫颈癌成像的双照明超声/光声系统


早期癌症检测技术可以提供功能信息，并有可能降低宫颈癌引起的死亡率。在我们之前的工作中，已经开发了一种微型超声和光声内窥镜系统，可以通过宫颈管对宫颈组织进行成像，以满足对安全、低成本和高分辨率功能诊断系统的需求。然而，内窥镜尺寸的小型化和美国国家标准协会的安全限制导致成像过程中使用高强度照明的限制。此外，组织的强光散射限制了光的穿透深度。幸运的是，子宫颈解剖结构允许通过使用外部照明系统从子宫颈外传递额外的光。在这里，我们提出了一种双共面照明系统，它可以通过组合的内部和外部光传输策略为宫颈组织提供足够的照明。因此，光与组织相互作用面积的增加使我们能够提高激光能量，同时将能量密度保持在安全限度内。因此，可以获得整个宫颈组织厚度的可靠 PA 成像。使用蒙特卡罗模拟测试系统性能，并计算激光能量密度并在模拟宫颈组织模型内的不同深度进行比较。结果表明蒙特卡罗模拟中的注量更高且更均匀。此外，该系统的光声成像通过两个模拟宫颈组织的模型进行了评估，其中包含人体血液和石墨棒。 根据模拟，模型研究揭示了模型整个深度的更可靠的光声信号，具有改进的对比度噪声比和信噪比，以及更高的成像视场覆盖率。总之，双模式照明系统可以在考虑安全限制的同时提供组织内包含物的更真实的信息，这可以提高宫颈癌诊断的生物标志物检测的准确性。