Multimodal photoacoustic and optical coherence tomography scanner using an all optical detection scheme for 3D morphological skin imaging

Abstract

A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for three-dimensional in vivo (3D) skin imaging is described. The system employs an integrated, all optical detection scheme for both modalities in backward mode utilizing a shared 2D optical scanner with a field-of-view of ~13 × 13 mm2. The photoacoustic waves were detected using a Fabry Perot polymer film ultrasound sensor placed on the surface of the skin. The sensor is transparent in the spectral range 590-1200 nm. This permits the photoacoustic excitation beam (670-680 nm) and the OCT probe beam (1050 nm) to be transmitted through the sensor head and into the underlying tissue thus providing a backward mode imaging configuration. The respective OCT and PAT axial resolutions were 8 and 20 µm and the lateral resolutions were 18 and 50-100 µm. The system provides greater penetration depth than previous combined PA/OCT devices due to the longer wavelength of the OCT beam (1050 nm rather than 829-870 nm) and by operating in the tomographic rather than the optical resolution mode of photoacoustic imaging. Three-dimensional in vivo images of the vasculature and the surrounding tissue micro-morphology in murine and human skin were acquired. These studies demonstrated the complementary contrast and tissue information provided by each modality for high-resolution 3D imaging of vascular structures to depths of up to 5 mm. Potential applications include characterizing skin conditions such as tumors, vascular lesions, soft tissue damage such as burns and wounds, inflammatory conditions such as dermatitis and other superficial tissue abnormalities.

Optical coherence tomography today: speed, contrast, and multimodality

“…To fully use the beyond optical mean free path feature of photoacoustic imaging, and to enable a large FOV with coregistered OCT/photoacoustics dual-modality imaging, an OCT/PAT system was introduced and tested in vivo. 240 Since this report, the system has been further developed and an SS OCT system with higher bandwidth has been incorporated with the optical detection whole-body illumination PAT system. The newest design of the system is given in Fig.…”

Three-dimensional imaging of normal skin and nonmelanoma skin cancer with cellular resolution using Gabor domain optical coherence microscopy

“…Recently OCT combined with PAT shows high-resolution structure together with cutaneous vasculature of in-vivo human skin. 35 Regardless of the type of extension or multimodality, the improvement in capability of OCT itself will enhance the overall performance of the combined system.…”

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

“…A MPT/confocal laser scanning microscopy system was used to investigate various dermatological diseases such as actinic keratosis and stucco keratosis [51]. Similarly, clinical trials using OCT in combination with imaging techniques such as Raman spectroscopy, coherent anti-Stokes Raman spectroscopy, photoacoustic tomography and fluorescence spectroscopy has been demonstrated and these multimodal systems were able to provide complimentary structural and functional information [52][53][54][55]. Recently, a multimodal optical microscope incorporating OCM, MPT and FLIM have been designed and developed to obtain images of human skin in vivo [56].…”