Three-dimensional multiphoton/optical coherence tomography for diagnostic applications in dermatology

A preliminary clinical trial using state-of-the-art multiphoton tomography (MPT) and optical coherence tomography (OCT) for three-dimensional (3D) multimodal in vivo imaging of normal skin, nevi, scars and pathologic skin lesions has been conducted. MPT enabled visualization of sub-cellular details with axial and transverse resolutions of <2 μm and <0.5 μm, respectively, from a volume of 0.35 × 0.35 × 0.2 mm(3) at a frame rate of 0.14 Hz (512 × 512 pixels). State-of-the-art OCT, operating at a center wavelength of 1300 nm, was capable of acquiring 3D images depicting the layered architecture of skin with axial and transverse resolutions ~8 μm and ~20 μm, respectively, from a volume of 7 × 3.5 × 1.5 mm(3) at a frame rate of 46 Hz (1024 × 1024 pixels). This study demonstrates the clinical diagnostic potential of MPT/OCT for pre-screening relatively large areas of skin using 3D OCT to identify suspicious regions at microscopic level and subsequently using high resolution MPT to obtain zoomed in, sub-cellular level information of the respective regions.