Portable, parallel 9-wavelength near-infrared spectral tomography (NIRST) system for efficient characterization of breast cancer within the clinical oncology infusion suite

Abstract

A portable near-infrared spectral tomography (NIRST) system was developed with simultaneous frequency domain (FD) and continuouswave (CW) optical measurements for efficient characterization of breast cancer in a clinical oncology setting. Simultaneous FD and CW recordings were implemented to speed up acquisition to 3 minutes for all 9 wavelengths, spanning a range from 661nm to 1064nm. An adjustable interface was designed to fit various breast sizes and shapes. Spatial images of oxy-and deoxy-hemoglobin, water, lipid, and scattering components were reconstructed using a 2D FEM approach. The system was tested on a group of 10 normal subjects, who were examined bilaterally and the recovered optical images were compared to radiographic breast density. Significantly higher total hemoglobin and water were estimated in the high density relative to low density groups. One patient with invasive ductal carcinoma was also examined and the cancer region was characterized as having a contrast ratio of 1.4 in total hemoglobin and 1.2 in water. ©2016 Optical Society of America

Collagen quantification in breast tissue using a 12-wavelength near infrared spectral tomography (NIRST) system

“…Based on a previously demonstrated 9-wavelength hybrid FD and CW NIRST system [25], a new 12-wavelength system has been developed, as shown in Fig. 1.…”

“…An open source software platform, NIRFAST [26], was used to process and calibrate boundary amplitude and phase data, make patient specific 2D FEM meshes, and reconstruct optical NIRST images. 2D spatial images of absorption related chromophore concentrations of oxy and deoxy-hemoglobin, water, and lipid content, and scattering amplitude and scattering power were reconstructed, using a reconstruction method with hybrid FD and CW data set [25]. The absorption spectrum of collagen content was encoded into the reconstruction procedure as well, which enabled tomographic recovery of collagen content, in addition to the other four chromophores.…”

“…In this paper, our previous system [25] was modified to combine 12-wavelengths of FD (capturing the complete tissue features in the 660-852nm wavelength range) and CW (for additional lipid and collagen features shown in the wavelength range of 850-1064nm). This NIRST system has been developed with two sets of simultaneous acquisitions of three FD and three CW wavelengths.…”

Ultrafast wavelength multiplexed broad bandwidth digital diffuse optical spectroscopy for in vivo extraction of tissue optical properties

“…This work focuses on FD-DOS, which allows for the separation of optical scattering and absorption through the measurement of amplitude attenuation and phase delay of photon density waves generated by temporally intensity modulated light sources at the tissue surface. Prior FD-DOS systems have utilized either a single modulation frequency [3][4][5][6][7][8][9] or a sweep of multiple frequencies [5][6][7] in the radio frequency (RF) range. Most single modulation frequency systems utilize either homodyne 4,7,8,10 or heterodyne 3 techniques to downconvert the high frequency signal of interest by mixing it with a reference signal.…”

A portable 12-wavelength parallel near-infrared spectral tomography (NIRST) system for efficient characterization of breast cancer during neoadjuvant chemotherapy

“…The photomultiplier (PMT) and photodiode (PD) detection module enabled both FD and CW acquisition. A novel scheme of simultaneous acquisition was introduced by Zhao et al [15] to significantly expedite the data acquisition. In this paper, a customized 6-wavelength FD subsystem has been introduced in order to improve spectral resolution.…”