Three-dimensional fluorescence-enhanced optical tomography using a hand-held probe based imaging system

Abstract

Hand-held based optical imaging systems are a recent development towards diagnostic imaging of breast cancer. To date, all the hand-held based optical imagers are used to perform only surface mapping and target localization, but are not capable of demonstrating tomographic imaging. Herein, a novel hand-held probe based optical imager is developed towards three-dimensional (3-D) optical tomography studies. The unique features of this optical imager, which primarily consists of a hand-held probe and an intensified charge coupled device detector, are its ability to; (i) image large tissue areas (5 x 10 sq. cm) in a single scan, (ii) perform simultaneous multiple point illumination and collection, thus reducing the overall imaging time; and (iii) adapt to varying tissue curvatures, from a flexible probe head design. Experimental studies are performed in the frequency domain on large slab phantoms (approximately 650 ml) using fluorescence target(s) under perfect uptake (1:0) contrast ratios, and varying target depths (1-2 cm) and X-Y locations. The effect of implementing simultaneous over sequential multiple point illumination towards 3-D tomography is experimentally demonstrated. The feasibility of 3-D optical tomography studies has been demonstrated for the first time using a hand-held based optical imager. Preliminary fluorescence-enhanced optical tomography studies are able to reconstruct 0.45 ml target(s) located at different target depths (1-2 cm). However, the depth recovery was limited as the actual target depth increased, since only reflectance measurements were acquired. Extensive tomography studies are currently carried out to determine the resolution and performance limits of the imager on flat and curved phantoms.

A wireless handheld probe with spectrally constrained evolution strategies for diffuse optical imaging of tissue

“…[4][5][6][7] These handheld probes image in reflectance mode with a 0.5-3.5 cm sourcedetector separation in order to probe beneath the tissue surface. They use a range of near-infrared wavelengths to determine the concentration of chromophores relevant to detecting tumors including oxy-and deoxy-hemoglobin, lipid, water, and scattering.…”

Performance Enhancement In Accuracy and Imaging Time of a Hand-Held Probe-Based Optical Imager

“…The multi-software co-registration approach used in the first generation optical imager [Ge, et al 2008;] will be converted to an automated software package. As the co-registration software is automated with a new software approach, the time of imaging will improve.…”

“…It consists of three major components; (i) the laser diode source (ii) an ICCD detector and (iii) the hand held probe [Ge, et al 2008;Jayachandran, et al 2007] as can be seen in figure 2.6. The hand held probe seen in figure 1.6 consists of 165 detector fibers, 6 source fibers and a 3-piece face capable of contouring to curved 15 surfaces with tissue surface contact.…”

“…3D tomography: Simultaneously tracks 3D positional information and optical data co-registered onto a mesh of the imaged surface [Ge, et al 2008;]. [Jayachandran, et al 2007] Optical images collected by the optical imager (2D surfaces) are used in appropriate inversion algorithms to obtain 3D image reconstructions.…”

“…The feasibility of co-registered imaging and 3D tomography studies on tissue phantoms have been demonstrated in the past. [Ge, et al 2008;Jayachandran, et al 2007]. However, there are limitations in our hand-held optical imaging system in the path of our ongoing clinical translational efforts.…”