Label-free Detection of Lymph Node Metastases with US-guided Functional Photoacoustic Imaging

Summary: Photoacoustic imaging imparts the ability to distinguish materials according to their differences in optical absorp- tion (ie, their color) with the high spatial and temporal resolution of ultrasonography (US). Experiments in rats show the advantages this approach would have in the clin- ically important noninvasive determination of the pres- ence of tumor in the lymph nodes draining a tumor, pro- viding the ability to achieve the results of total axillary lymph node dissection without the risks of surgery or even percutaneous sentinel node biopsy. The coupling of this technique to a conventional US imaging system gives the promise of rapid translation to clinical use.