Enhanced diffuse optical tomographic reconstruction using concurrent ultrasound information

Abstract

Multimodal imaging is an active branch of research as it has the potential to improve common medical imaging techniques. Diffuse optical tomography (DOT) is an example of a low resolution, functional imaging modality that typically has very low resolution due to the ill-posedness of its underlying inverse problem. Combining the functional information of DOT with a high resolution structural imaging modality has been studied widely. In particular, the combination of DOT with ultrasound (US) could serve as a useful tool for clinicians for the formulation of accurate diagnosis of breast lesions. In this paper, we propose a novel method for US-guided DOT reconstruction using a portable time-domain measurement system. B-mode US imaging is used to retrieve morphological information on the probed tissues by means of a semi-automatical segmentation procedure based on active contour fitting. A two-dimensional to three-dimensional extrapolation procedure, based on the concept of distance transform, is then applied to generate a three-dimensional edge-weighting prior for the regularization of DOT. The reconstruction procedure has been tested on experimental data obtained on specifically designed dual-modality silicon phantoms. Results show a substantial quantification improvement upon the application of the implemented technique. This article is part of the theme issue ‘Synergistic tomographic image reconstruction: part 2’.

Evaluation of a pipeline for simulation, reconstruction, and classification in ultrasound-aided diffuse optical tomography of breast tumors

“…After that, we apply the prior extraction procedure as described in Ref. 73 . As a second assessment, we analyze the performances of the optical reconstructions.…”

“…For each inclusion, a set of three to four control points was selected close to the internal border of the inclusion itself. An algorithm based on snake fitting 73 , 74 retrieved a segmentation of the image as shown in Figs. 6(b) and 6(d) .…”

“…6 , we show the results of the extrapolation routine described in Ref. 73 . An assessment of the extrapolation procedure was performed by means of the Sørensen-Dice index (SDI): 75 – 77 where and are the ’th elements of two binary images and ranging from 0 and 1, of the volume mismatch and of the displacement between the center of mass of ground truth and of the retrieved images.…”

Synergistic tomographic image reconstruction: part 2

“…Di Sciacca et al [ 12 ] present a method for Diffuse Optical Tomographic (DOT) reconstruction using concurrent ultrasound information as guidance. The inverse problem in DOT has a nonlinear forward model and is highly ill-posed.…”

Objective Numerical Evaluation of Diffuse, Optically Reconstructed Images Using Structural Similarity Index

“…In the measurement system, several pairs of light sources and detectors are attached around a subject or phantom model to acquire the light radiance distribution. In the computation procedure, a reconstruction image algorithm is utilized to predict optical properties inside the tissue [ 2 , 3 ]. The DOT technique is an invasive modality because it uses the near-infrared (NIR) spectral window to image the structural and functional properties of human tissue.…”