Noninvasive cerebral optical spectroscopy: Depth-resolved measurements of cerebral haemodynamics using indocyanine green

Abstract
To investigate the feasibility of a newly developednear-infrared optical spectroscopy device, we analysed measurements of the infrared tracer indocyanine green (ICC) using sensors with a single near infrared light source and multiple light detectors. Two ml of ICC dye, 1.0 mg ml~1 in concentration, were injected into the internal carotid artery during cerebral angiography in 14 adult patients. The resultant washout curves were measured bilaterally using sensors with 4 detectors spaced at 10, 20, 30 and 40 mm from the infrared light source on the right side, and 15, 25, 35 and 45 mm from the source for the left side, respectively. Washout curves were analysed to determine the relative amplitude of the ICC absorption signal and deduce each detector’s penetration distance. When ICC was injected into the internal carotid artery, relative absorption increased with detector distance from the light source. No substantial difference in attenuation was observed in any of the detectors during external carotid injection of ICC. The resultant information related depth of penetration of the light with source-detector separation distances. The feasibility of the system for measuring cerebral oxygen saturation and haemodynamics noninvasively or monitoring at bedside is discussed. [Neurol Res 1995; 17:89–93]

This publication has 0 references indexed in Scilit: