Three-dimensional fluorescence tomography of human breast tissuesin vivousing a hand-held optical imager

Abstract

Diffuse optical imaging using non-ionizing radiation is a non-invasive method that shows promise towards breast cancer diagnosis. Hand-held optical imagers show potential for clinical translation of the technology, yet they have not been used towards 3D tomography. Herein, 3D tomography of human breast tissue in vivo is demonstrated for the first time using a hand-held optical imager with automated coregistration facilities. Simulation studies are performed on breast geometries to demonstrate the feasibility of 3D tomographic imaging using a hand-held imager under perfect (1:0) and imperfect (100:1, 50:1) fluorescence absorption contrast ratios. Experimental studies are performed in vivo using a 1 μM ICG filled phantom target placed non-invasively underneath the flap of the breast tissue. Results show the ability to perform automated tracking and coregistered imaging of human breast tissue (with tracking accuracy on the order of ~1 cm). Three-dimensional tomography results demonstrated the ability to recover a single target placed at a depth of 2.5 cm, from both the simulated (at 1:0, 100:1 and 50:1 contrasts) and experimental cases on actual breast tissues. Ongoing efforts to improve target depth recovery are carried out via implementation of transmittance imaging in the hand-held imager.

Point-of-care and point-of-procedure optical imaging technologies for primary care and global health

“…A representative example of a mid-stage PoC technology is the implementation of fluorescence microscopy as a replacement for bright-field microscopy (10). Representative mid-stage PoP technologies include the handheld scanner for spectroscopic imaging of breast tumors and tissue for assessing treatment response (37, 51), as well as the array of optical techniques to evaluate the field effect of carcinogenesis during gastrointestinal imaging procedures (38). Late-stage technologies are those that have been widely evaluated in clinical trials and have been adopted by health care providers and integrated into health care systems.…”

Biophotonics for assessing breast cancer

“…The probe was used to demonstrate 2D target detection ) and co-registered imaging and 3D tomography (Erickson et al, 2013) in human subjects. The breast geometry was acquired using a commercially available scanner.…”

“…(b) The imaging setup where the initial 2D surface map is displayed in near real-time (mannequin shown for demonstration) (Erickson et al (2013),. (a) The system is composed of a laser diode source, a CCD camera detector, and the handheld probe (inset) that contains six source points (large dots) and 165 detection points (small dots).…”

“…(d) Co-registered image of a target placed at 8 o'clock Erickson et al (2013),. Tumor-mimicking targets (filled with indocyanine green) were superficially placed under the breast of a healthy female subject.…”

Noninvasive surface imaging of breast cancer in humans using a hand-held optical imager

“…Extensive tissue phantom studies were performed to demonstrate 3D tomographic imaging capabilities of the imager (30, 35) as well as improved target depth detection (36). In vivo 3D tomographic breast imaging studies (on healthy subjects containing superficially placed tumor-like targets) were demonstrated using the hand-held optical imager (33). In parallel, a gen-2 version of the hand-held optical imager was also developed and its ability to detect targets was demonstrated in phantoms and human breast tissue (37–38).…”