Accurate assessment of the size and depth of infiltration is critical for effectively treating and removing skin cancer, especially melanoma. However, existing methods such as skin biopsy and histologic examination are invasive, time-consuming, and may not provide accurate depth results. We present a novel system for simultaneous and co-localized ultrasound and photoacoustic imaging, with the application for non-invasive skin lesion size and depth measurement. The developed system integrates an acoustical mirror that is placed on an ultrasound transducer, which can be translated within a flexible water tank. This allows for 3D (C-mode) imaging, which is useful for mapping the skin structure and determine the invasion size and depth of lesions including skin cancer. For efficient reconstruction of photoacoustic images, we applied the open-source MUST library. The acquisition time per 2D image is <1 s and the pulse energies are below the legal Maximum Permissible Exposure (MPE) on human skin. We present the depth and resolution capabilities of the setup on several self-designed agar phantoms and demonstrate in vivo imaging on human skin. The setup also features an unobstructed optical window from the top, allowing for simple integration with other optical modalities. The perspective towards clinical application is demonstrated.

准确评估浸润的大小和深度对于有效治疗和去除皮肤癌，尤其是黑色素瘤至关重要。然而，现有的方法（例如皮肤活检和组织学检查）是侵入性的、耗时的，并且可能无法提供准确的深度结果。我们提出了一种新颖的同步共定位超声和光声成像系统，可用于非侵入性皮肤病变尺寸和深度测量。开发的系统集成了放置在超声波换能器上的声镜，超声波换能器可以在柔性水箱内平移。这允许进行 3D（C 模式）成像，这对于绘制皮肤结构并确定包括皮肤癌在内的病变的侵袭大小和深度非常有用。为了高效重建光声图像，我们应用了开源 MUST 库。每个 2D 图像的采集时间 <1 秒，脉冲能量低于人体皮肤的法定最大允许暴露 (MPE)。我们在几个自行设计的琼脂模型上展示了该装置的深度和分辨率能力，并在人体皮肤上演示了体内成像。该装置还具有顶部无障碍光学窗口，可以与其他光学模式简单集成。展示了临床应用的前景。