Clinical Translation of a Novel Hand-Held Based Optical Imager: In Vitro and In Vivo Studies

Abstract

Hand-held based optical imaging devices are currently developed by researchers toward clinical translation of the technology. However, the devices developed to date are limited in that they are unable to contour to different tissue curvatures, and they are not capable of coregistration which is necessary for 3D tomography. A novel hand-held based optical imager has been developed in our Optical Imaging Laboratory and tested on homogeneous tissue phantoms. The unique features of the device include (i) flexibility to contour to different tissue curvatures, (ii) simultaneous illumination for rapid data acquisition, and (iii) real-time coregistration capabilities to enable 3D tomography. Herein, studies are performed to demonstrate the ability of the hand-held device to image in vitro samples designed to better mimic the heterogeneous nature of human breast tissue. A fluorescent target (0.45 cc) filled with 1 μM indocyanine green (ICG) was used to represent a tumor and placed at different depths up to 2.5 cm within a 10x10x10 cm³ acrylic cube filled with minced chicken breast and 1% Liposyn. The hand-held device was used to recover the target location from 2D surface contour plots of the fluorescent signal. Parallely, preliminary in vivo studies have been carried out on normal human subjects using a simulated fluorescent target (0.45cc), where the probe was placed on the tissue surface with gentle compression. These studies demonstrate the potential for clinical translation of our hand-held based optical imager for real-time tomographic imaging.