Study of near infrared imaging of a model of brain edema

Currently, methods for the detection of brain edema in patients or laboratory experiments are not ideal. MRI does not permit time resolution of injury and intracranial pressure monitoring is invasive. The authors have performed experiments on a model of brain edema to examine near infrared imaging as a convenient, low cost and noninvasive method of monitoring brain edema. The authors prepared an in vitro model of edema consisting of serial dilutions of Intralipid/sup TM/, a fat emulsion, to simulate varying degrees of brain water content. NIR light at two wavelengths (920 nm and 980 nm) was used to assess the water content of Intralipid/sup TM/. The authors obtained a correlation coefficient of 0.98 between water content and NIR absorption difference. They used the CCD system to image a model with spatial variations in water content. Their preliminary results suggest NIR spectroscopy as a useful technique for monitoring brain edema in both clinical and laboratory settings.