Elastic net regularization in diffuse optical tomography applications
Contributo in Atti di convegno
Data di Pubblicazione:
2019
Citazione:
Elastic net regularization in diffuse optical tomography applications / P. Causin, G. Naldi, R.M. Weishaeupl (PROCEEDINGS INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING). - In: 2019 IEEE 16th International Symposium on Biomedical Imaging (ISBI 2019)[s.l] : IEEE, 2019. - ISBN 9781538636411. - pp. 1627-1630 (( Intervento presentato al 16. convegno IEEE International Symposium on Biomedical Imaging (ISBI) tenutosi a Venezia nel 2019 [10.1109/ISBI.2019.8759476].
Abstract:
Diffuse optical tomography (DOT) uses near-infrared light to obtain quantitative information about the optical coefficients in biological tissues. Such an information can be clinically exploited for diagnostic purposes. In DOT, the surface of the investigated tissue is illuminated with a light source and the emerging light is measured at various locations on the surface itself. The minimization of the discrepancy between the observed data and the corresponding field generated by a mathematical model of light propagation is then performed, yielding an estimated distribution of the optical parameters in the tissue. This problem is characterized by severe ill-conditioning, so that appropriate regularization techniques must be applied to obtain a meaningful solution. To do this, the use of ell-2 (Tikhonov) penalization has been generally advocated in this context; more recently, ell-1 (LASSO)-norm penalization has also been proposed to detect the existence of sparsity patterns. Both approaches are classical regularization techniques and are often favored in DOT over other methods, when robustness with respect to geometry and need for almost real-time results are an issue. The goal of the present contribution is to explore the 'elastic net' regularization technique originally introduced by Zou and Hastie [1], that shares the desirable properties of both the ell-2-- and ell-1-norm penalization approaches. Whilst this technique has been largely used as a learning theory tool in different applications, at the best of our knowledge, this paper presents its first use in DOT applications. Numerical simulations are performed here on a simple 2D geometry, to assess the potentialities of this approach. The results show that this technique may be a good choice for our target application, where DOT is used as a cheap, first-level and almost real-time screening technique for breast cancer detection.
Tipologia IRIS:
03 - Contributo in volume
Keywords:
Diffuse optical tomography; inverse problem regularization; elastic net; LASSO; Tikhonov
Elenco autori:
P. Causin, G. Naldi, R.M. Weishaeupl
Link alla scheda completa:
Titolo del libro:
2019 IEEE 16th International Symposium on Biomedical Imaging (ISBI 2019)