Maps of optical differential pathlength factor of human adult forehead, somatosensory motor and occipital regions at multi-wavelengths in NIR
| Autor: | Yukari Tanikawa, Yukio Yamada, Kenji Tanaka, Huijuan Zhao, Angelo Sassaroli, Feng Gao, Yoichi Onodera |
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| Rok vydání: | 2002 |
| Předmět: |
Models
Statistical Spectroscopy Near-Infrared Time Factors Materials science Light Radiological and Ultrasound Technology business.industry Near-infrared spectroscopy Temple region Brain Somatosensory system Magnetic Resonance Imaging Wavelength Mri image Optical imaging medicine.anatomical_structure Optics Forehead medicine Humans Radiology Nuclear Medicine and imaging business Monte Carlo Method |
| Zdroj: | Physics in Medicine and Biology. 47:2075-2093 |
| ISSN: | 0031-9155 |
| DOI: | 10.1088/0031-9155/47/12/306 |
| Popis: | The optical differential pathlength factor (DPF) is an important parameter for physiological measurement using near infrared spectroscopy, but for the human adult head it has been available only for the forehead. Here we report measured DPF results for the forehead, somatosensory motor and occipital regions from measurements on 11 adult volunteers using a time-resolved optical imaging system. The optode separation was about 30 mm and the wavelengths used were 759 nm, 799 nm and 834 nm. Measured DPFs were 7.25 for the central forehead and 6.25 for the temple region at 799 nm. For the central somatosensory and occipital areas (10 mm above the inion), DPFs at 799 nm are 7.5 and 8.75, respectively. Less than 10% decreases of DPF for all these regions were observed when the wavelength increased from 759 nm to 834 nm. To compare these DPF maps with the anatomical structure of the head, a Monte Carlo simulation was carried out to calculate DPF for these regions by using a two-layered semi-infinite model and assuming the thickness of the upper layer to be the sum of the thicknesses of scalp and skull, which was measured from MRI images of a subject's head. The DPF data will be useful for quantitative monitoring of the haemodynamic changes occurring in adult heads. |
| Databáze: | OpenAIRE |
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