Combined Multimodal Photoacoustic Tomography, Optical Coherence Tomography (Oct) And Oct Based Angiography System For In Vivo Imaging Of Multiple Skin Disorders In Human

All optical photoacoustic tomography (PAT) using a planar Fabry-Perot interferometer polymer film sensor has been demonstrated for in vivo human palm imaging with an imaging penetration depth of 5 mm. The relatively larger vessels in the superficial plexus and the vessels in the dermal plexus are visible in PAT. However, due to both resolution and sensitivity limits, all optical PAT cannot reveal the smaller vessels such as capillary loops and venules. Melanin absorption also sometimes causes difficulties in PAT to resolve vessels. Optical coherence tomography (OCT) based angiography, on the other hand, has been proven suitable for microvasculature visualization in the first couple millimeters in human. In our work, we combine an all optical PAT system with an OCT system featuring a phase stable akinetic swept source. This multimodal PAT/OCT/OCT-angiography system provides us co-registered human skin vasculature information as well as the structural information of cutaneous. The scanning units of the sub-systems are assembled into one probe, which is then mounted onto a portable rack. The probe and rack design gives six degrees of freedom, allowing the multimodal optical imaging probe to access nearly all regions of human body. Utilizing this probe, we perform imaging on patients with various skin disorders as well as on healthy controls. Fused PAT/OCT-angiography volume shows the complete blood vessel network in human skin, which is further embedded in the morphology provided by OCT. A comparison between the results from the disordered regions and the normal regions demonstrates the clinical translational value of this multimodal optical imaging system in dermatology.