Non-invasive multimodal optical coherence and photoacoustic tomography for human skin imaging

Abstract

The cutaneous vasculature is involved in many diseases. Current clinical examination techniques, however, cannot resolve the human vasculature with all plexus in a non-invasive manner. By combining an optical coherence tomography system with angiography extension and an all optical photoacoustic tomography system, we can resolve in 3D the blood vessels in human skin for all plexus non-invasively. With a customized imaging unit that permits access to various parts of patients’ bodies, we applied our multimodality imaging system to investigate several different types of skin conditions. Quantitative vascular analysis is given for each of the dermatological conditions to show the potential diagnostic value of our system in non-invasive examination of diseases and physiological processes. Improved performance of our system over its previous generation is also demonstrated with an updated characterization.

Automatic skin lesion area determination of basal cell carcinoma using optical coherence tomography angiography and a skeletonization approach: Preliminary results

“…With a customized imaging unit, the system can access various parts of the patients' bodies. For details of the system please refer to previous studies .…”

Deep learning robotic guidance for autonomous vascular access

“…5d and Supplementary Figs. [16][17][18][19]. Robotic cannulation also reduced, among the total failed vascular access attempts, the percentage of unintended punctures of the posterior wall, as identified by visualization under B-mode US ( Fig.…”

“…The challenges of difficult vascular access have driven the development of imaging technologies that fall into four main categories: (1) tactile pressure-based imaging, which can provide maps of tissue elastic response with sensitivities of several pascals but at poor spatial resolutions (>1 mm) 16 ; (2) optical coherence tomography and photoacoustic tomography, which have demonstrated spatial resolutions of 0.01-0.1 mm but with limited imaging depth (1-2 mm) [17][18][19][20] ; (3) near-infrared (NIR) optical imaging, which utilizes 700-1,000 nm light from lasers or light-emitting diodes (LEDs) to image superficial vessels within 5 mm of the tissue surface 21,22 , but which does not accurately estimate vessel depth beneath the skin; (4) ultrasound (US) imaging, which has seen the greatest clinical adoption and been correlated to higher vascular access success and lower complication rates compared to blind cannulation [23][24][25] . Modern clinical linear-array US transducers can resolve submillimetre tissue structures at suitable depths (0.5-10 cm for frequencies of 5-20 MHz) and estimate blood flow velocities using Doppler-based modalities.…”

Non‐invasive imaging in dermatology and the unique potential of raster‐scan optoacoustic mesoscopy

“…To the best of our knowledge, microscopic optoacoustic devices have not yet entered clinical research . Optoacoustic mesoscopy methods use non‐focused illumination schemes in combination with a focused ultrasound detector, which enables imaging to depths of several millimetres while keeping high resolution . A fundamental limitation of previous systems has, however, been the narrow bandwidth of the applied ultrasound detectors.…”

“…46,[50][51][52][53] Optoacoustic mesoscopy methods use non-focused illumination schemes in combination with a focused ultrasound detector, which enables imaging to depths of several millimetres while keeping high resolution. [54][55][56][57][58] A fundamental limitation of previous systems has, however, been the narrow bandwidth of the applied ultrasound detectors. The span of ultrasonic frequencies emitted by microvessels is very broad and depends on their size and depth.…”