Algorithm for in vivo detection of tissue type from multiple scattering light phase images

Abstract

In vivo physiological assessments are typically done by either imaging techniques or by sensing changes in the attenuation coefficient. Using visible or near-infrared (NIR), imaging is mainly possible for thin tissues. On the other hand, clinical information can also be detected by examining changes in tissue optical properties. The most challenging aspect in sensing techniques is the spectral dependent scattering, which varies with the physiological state and tissue type. We have previously published our novel noninvasive nanophotonics technique for detecting tissue scattering based on reflectance measurements: the iterative multi-plane optical property extraction (IMOPE). The IMOPE reconstructs the reemitted light phase using an iterative algorithm and extracts the scattering properties based on a theoretical model. This paper presents the in vivo application of distinguishing between different mouse tissue areas. The reconstructed phase images reveal different areas in the inner thigh of a mouse, which are related to the muscle, bone, and skin. The IMOPE uses the reconstructed phases for sensing and detecting unseen components beneath the skin surface. This technique could be further applied to the diagnosis of various physiological states.

Depth Scattering Characterization of Multi-Layer Turbid Media Based on Iterative Multi-Plane Reflectance Measurements

“…The light intensity images are then processed by the GS algorithm in order to reconstruct the reemitted light phase. The reconstruction is done by the multi-plane GS algorithm which was detailed in [23]. Once the reemitted light phase is reconstructed, its distribution, specifically its RMS, is computed based on:  is the average phase, and  is the spatial region of interest (ROI).…”

“…The IMOPE starts with recording light intensity images at different locations using the experimental setup. The images are then processed by the multi-plane GS algorithm (as detailed in [23]) to reconstruct the phase image. Next, the RMS of the phase image is calculated based on Eq.…”

“…We have presented previously the iterative multi-plane optical property extraction (IMOPE) technique [19][20][21][22][23][24][25]. The IMOPE technique is a noninvasive nanophotonics technique for extracting the scattering properties of a medium based on a single light source.…”

“…Citation information: DOI 10.1109/JPHOT.2020.3017697, IEEE Photonics Journal 2 based on the steady-state diffusion reflection theory [29][30][31] with the master-slave dual-source configuration [32]. The reflection-based IMOPE was applied for tissues viability test and detection of gold nanorods and blood flow in the femoral vein of a mouse [21], and also the detection of different tissue types of a mouse [23]. Mostly, the IMOPE was applied for biomedical purposes hence the red wavelength was used.…”

“…First, single layer tissue-like phantoms were measured by the IMOPE, for calibration purposes. As was reported before [22][23][24][25], two distinguishable regions were visible in the phase images and were marked manually as two spatial regions that correlated to two scattering regimes. Here, a methodology for finding these two regions automatically based on RMS computations from the phase images is presented.…”