Looking for a perfect match: multimodal combinations of Raman spectroscopy for biomedical applications

Abstract

In our previous publication, “In-vivo Raman spectroscopy: from basics to applications,”1 we have provided a comprehensive review on a variety of technological developments and in vivo applications for Raman spectroscopy (RS). The goal of the aforementioned review was to outline to novice researchers the important factors, which are crucial for the translation of RS to in vivo applications. We discussed instrument parameters that are most relevant and suitable for developing Raman systems in a clinical setting. We have also outlined a variety of possible fiber-probe implementations, which are readily available, and included various designs for endoscopic probes, e.g., ball-lens focusing and side-viewing probes. Also, handheld probes, which can be used for the characterization of molecular information on surfaces, were presented. Additionally, we briefly touched on spatially offset Raman spectroscopy (SORS) and implementations that include image guidance. The reviewed applications focused on cardiovascular diseases, inflammatory diseases, and cancer. The latter was separately reviewed for brain, skin, head and neck, breast, digestive and urinary system, and prostate and cervix. In essence, our previous review provided an in-depth assessment on instrumentation and in vivo applications of RS. A major topic that we touched only briefly in the previous review is the multimodal implementation of RS for in vivo diagnostics. However, we truly believe that in the near- and long-term future, the implementation of multimodal optical diagnostic systems will be one of the most important topics and drivers for a clinical translation, and RS will play an exceptional role in this translation. This review provides an overview on the different combinations of RS with other optical modalities.