Multi-modulated frequency domain high density diffuse optical tomography

Abstract

Frequency domain (FD) high density diffuse optical tomography (HD-DOT) utilising varying or combined modulation frequencies (mFD) has shown to theoretically improve the imaging accuracy as compared to conventional continuous wave (CW) measurements. Using intensity and phase data from a solid inhomogeneous phantom (NEUROPT) with three insertable rods containing different contrast anomalies, at modulation frequencies of 78 MHz, 141 MHz and 203 MHz, HD-DOT is applied and quantitatively evaluated, showing that mFD outperforms FD and CW for both absolute (iterative) and temporal (linear) tomographic imaging. The localization error (LOCA), full width half maximum (FWHM) and effective resolution (ERES) were evaluated. Across all rods, the LOCA of mFD was 61.3% better than FD and 106.1% better than CW. For FWHM, CW was 6.0% better than FD and mFD and for ERES, mFD was 1.20% better than FD and 9.83% better than CW. Using mFD data is shown to minimize the effect of inherently noisier FD phase data whilst maximising its strengths through improved contrast.

Multi paradigm frequency domain workflow for human brain imaging

“…Using intensity and phase together can alleviate the weaknesses of phase whilst utilising it's benefits, which has been shown before on phantom models. 6 We have designed a workflow to allow multiple paradigms of parameter recovery to be performed simultaneously, namely normal single channel spectroscopy, multi channel tomography, short channel regression and dual slope reconstruction. We have also shown an optical registration method to create subject specific atlas models.…”

Machine Learning Diffuse Optical Tomography Using Extreme Gradient Boosting and Genetic Programming

“…Imaging with randomly scattered light is a significant challenge with a pressing need in non-invasive biomedical diagnosis [ 1 , 2 , 3 , 4 , 5 , 6 ]. One of the more significant applications is a non-invasive functional imaging technique called diffuse optical tomography (DOT), which uses near-infrared (NIR) light to map in 3D the optical characteristics of tissue by penetrating it deeply [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”