A, Schematic illustration of a multispectral optoacoustic tomography (MSOT)/optoacoustic ultrasonographic (OPUS)–guided fine-needle biopsy. B, Inguinal lymph node, ultrasonographic image, C, MSOT image correlating with panel A showing no indocyanine green (ICG) signal. D, Hybrid image of panels B and C. E, Inguinal lymph node, ultrasonographic image, with biopsy needle. F, MSOT image showing ICG, correlating with panel E. G, Hybrid image of panels E and F. H, Lymph node histologic examination (hematoxylin-eosin staining; original magnification x40) with biopsy channel. a.u. indicates auxiliary unit.