Deep Learning of Diffuse Optical Tomography Based on Time-Domain Radiative Transfer Equation
Near infrared diffuse optical tomography (DOT) is a potential tool for diagnosing cancer by image reconstruction of tissue optical properties. A variety of image reconstruction methods for DOT have been attempted, in general, based on the diffusion equation (DE). However, the image quality is still...
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MDPI AG
2022-12-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/24/12511 |
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| author | Yuichi Takamizu Masayuki Umemura Hidenobu Yajima Makito Abe Yoko Hoshi |
| author_facet | Yuichi Takamizu Masayuki Umemura Hidenobu Yajima Makito Abe Yoko Hoshi |
| author_sort | Yuichi Takamizu |
| collection | DOAJ |
| description | Near infrared diffuse optical tomography (DOT) is a potential tool for diagnosing cancer by image reconstruction of tissue optical properties. A variety of image reconstruction methods for DOT have been attempted, in general, based on the diffusion equation (DE). However, the image quality is still insufficient to clinical use, which is mainly attributed to the fact that the DE is invalid in some regions, such as low-scattering regions, and the inverse problem is inherently ill-posed. In contrast, the radiative transfer equation (RTE) accurately describes light propagation in biological tissue and also the DOT by deep learning is recently thought to be an alternative approach to the inverse problem. Distribution of time of flight (DTOF) of photons estimated by the time-domain RTE lends itself to deep learning along a temporal sequence. In this study, we propose a new DOT image reconstruction algorithm based on a long-short-term memory and the time-domain RTE. In simulation studies, using this algorithm, we succeeded in detection of an absorbing inclusion with a diameter of 5 mm, an absorber mimicking cancer, which was embedded in a two-dimensional square model (4 cm × 4 cm) with an optically homogeneous background. Multiple absorbers and a bigger absorber embedded in this model were also detected. We also demonstrate that, if simulation data by beam injection from multiple directions are employed as a training set, the accuracy of detection is improved especially for multiple absorbers. |
| first_indexed | 2024-03-09T17:22:47Z |
| format | Article |
| id | doaj.art-2517493d0bb44da191d019f7a758532c |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T17:22:47Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-2517493d0bb44da191d019f7a758532c2023-11-24T12:59:52ZengMDPI AGApplied Sciences2076-34172022-12-0112241251110.3390/app122412511Deep Learning of Diffuse Optical Tomography Based on Time-Domain Radiative Transfer EquationYuichi Takamizu0Masayuki Umemura1Hidenobu Yajima2Makito Abe3Yoko Hoshi4Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, JapanCenter for Computational Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, JapanCenter for Computational Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, JapanCenter for Computational Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, JapanPreeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, JapanNear infrared diffuse optical tomography (DOT) is a potential tool for diagnosing cancer by image reconstruction of tissue optical properties. A variety of image reconstruction methods for DOT have been attempted, in general, based on the diffusion equation (DE). However, the image quality is still insufficient to clinical use, which is mainly attributed to the fact that the DE is invalid in some regions, such as low-scattering regions, and the inverse problem is inherently ill-posed. In contrast, the radiative transfer equation (RTE) accurately describes light propagation in biological tissue and also the DOT by deep learning is recently thought to be an alternative approach to the inverse problem. Distribution of time of flight (DTOF) of photons estimated by the time-domain RTE lends itself to deep learning along a temporal sequence. In this study, we propose a new DOT image reconstruction algorithm based on a long-short-term memory and the time-domain RTE. In simulation studies, using this algorithm, we succeeded in detection of an absorbing inclusion with a diameter of 5 mm, an absorber mimicking cancer, which was embedded in a two-dimensional square model (4 cm × 4 cm) with an optically homogeneous background. Multiple absorbers and a bigger absorber embedded in this model were also detected. We also demonstrate that, if simulation data by beam injection from multiple directions are employed as a training set, the accuracy of detection is improved especially for multiple absorbers.https://www.mdpi.com/2076-3417/12/24/12511diffuse optical tomographytime-domain radiative transfer equationdeep learning |
| spellingShingle | Yuichi Takamizu Masayuki Umemura Hidenobu Yajima Makito Abe Yoko Hoshi Deep Learning of Diffuse Optical Tomography Based on Time-Domain Radiative Transfer Equation Applied Sciences diffuse optical tomography time-domain radiative transfer equation deep learning |
| title | Deep Learning of Diffuse Optical Tomography Based on Time-Domain Radiative Transfer Equation |
| title_full | Deep Learning of Diffuse Optical Tomography Based on Time-Domain Radiative Transfer Equation |
| title_fullStr | Deep Learning of Diffuse Optical Tomography Based on Time-Domain Radiative Transfer Equation |
| title_full_unstemmed | Deep Learning of Diffuse Optical Tomography Based on Time-Domain Radiative Transfer Equation |
| title_short | Deep Learning of Diffuse Optical Tomography Based on Time-Domain Radiative Transfer Equation |
| title_sort | deep learning of diffuse optical tomography based on time domain radiative transfer equation |
| topic | diffuse optical tomography time-domain radiative transfer equation deep learning |
| url | https://www.mdpi.com/2076-3417/12/24/12511 |
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