Three-dimensional imaging of skin melanoma in vivo by dual-wavelength photoacoustic microscopy

TLDR

The absorption coefficients of blood and melanin‑pigmented melanomas differ markedly at 764 nm and 584 nm. Dual‑wavelength reflection‑mode photoacoustic microscopy noninvasively acquires 3‑D images of subcutaneous melanomas and their surrounding vasculature in vivo. High‑resolution dual‑wavelength photoacoustic imaging revealed the 3‑D melanin distribution and ~0.5 mm melanoma thickness, visualized surrounding vasculature and tumor‑feeding vessels, and suggests utility for melanoma diagnosis, prognosis, and treatment planning.

Abstract

Dual-wavelength reflection-mode photoacoustic microscopy is used to noninvasively obtain three-dimensional (3-D) images of subcutaneous melanomas and their surrounding vasculature in nude mice in vivo. The absorption coefficients of blood and melanin-pigmented melanomas vary greatly relative to each other at these two optical wavelengths (764 and 584 nm). Using high-resolution and high-contrast photoacoustic imaging in vivo with a near-infrared (764-nm) light source, the 3-D melanin distribution inside the skin is imaged, and the maximum thickness of the melanoma (~0.5 mm) is measured. The vascular system surrounding the melanoma is also imaged with visible light (584 nm) and the tumor-feeding vessels found. This technique can potentially be used for melanoma diagnosis, prognosis, and treatment planning.