Transcranial measurement of diffuse light reflectance from cold-injured brains in rats

Yoshinori Ueda; Shunichi Sato; Hiroshi Ashida; Hidetoshi Ooigawa; Hiroshi Nawashiro; Katsuji Shima; Daizoh Saitoh; Yoshiaki Okada; Minoru Obara

doi:10.1117/1.2136386

1 November 2005 Transcranial measurement of diffuse light reflectance from cold-injured brains in rats

Yoshinori Ueda, Shunichi Sato, Hiroshi Ashida, Hidetoshi Ooigawa, Hiroshi Nawashiro, Katsuji Shima, Daizoh Saitoh, Yoshiaki Okada, Minoru Obara

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Journal of Biomedical Optics, Vol. 10, Issue 6, 064010 (November 2005). https://doi.org/10.1117/1.2136386

Abstract

Diagnosis of brain edema is important to manage severe head injuries and diseases, but there is no method of noninvasive bedside monitoring of brain edema. We speculate that brain edema changes the optical properties of brain tissue. To verify this speculation, we perform transcranial measurement of diffuse light reflectance from cold-injured brains in rats. To induce edema, a liquid nitrogen-cooled copper probe of 3 mm diameter was applied to the right parietal bone for 60 s under anesthesia. The rat skull was irradiated with 633-nm HeNe laser light and 532-nm Nd:YVO₄ laser light, which were used to investigate changes in light scattering and blood flow, respectively. Reflectance intensity was measured as functions of time and position on the skull. We found that reflectance intensities were significantly decreased around the cold injury at both 633 and 532 nm, while reflectance was increased in the cold injury at 532 nm, indicating that cerebral blood volume was decreased in the cold injury. Under the condition of decreased cerebral blood volume, the decrease in reflectance intensity around the injury suggests that the scattering coefficient of brain tissue was reduced due to edema formation in this area.

©(2005) Society of Photo-Optical Instrumentation Engineers (SPIE)

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Yoshinori Ueda, Shunichi Sato, Hiroshi Ashida, Hidetoshi Ooigawa, Hiroshi Nawashiro, Katsuji Shima, Daizoh Saitoh, Yoshiaki Okada, and Minoru Obara "Transcranial measurement of diffuse light reflectance from cold-injured brains in rats," Journal of Biomedical Optics 10(6), 064010 (1 November 2005). https://doi.org/10.1117/1.2136386

Published: 1 November 2005

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