The purpose of this study was to compare the effectiveness of an optically-based tomographic imaging system versus conventional ultrasound for the detection of intraventricular hemorrhage in the premature neonate. A real-time bedside monitor for high-risk patients might allow care to be changed early in the course of injury, possibly preventing such injury from becoming irreversible, as well as permit monitoring of the efficacy of any intervention. Low-level visible and near-infrared light pass through human bone and tissue in small amounts, and the time of photon transit through the tissue can be used to measure tissue oxygenation as well as to reconstruct tissue images (Benaron, Science, 1993). We had previously described construction of an optical imaging system and had tested this device in model systems and pathological brain samples (van Houten, Ped. Res., in press). We then converted the device into a real-time clinical scanner. Premature infants undergoing ultrasound examination were, after informed consent, scanned optically as well. Optical images were read in a blinded manner. Optical scanning correctly identified the site and grade of bleeding in 75% of cases, with one of the two incorrect diagnoses explainable based upon the age of the bleed, and the other error occurring as a missed evolving bleed of intermediate grade. In the first case, a clot visualized in earlier optical scans of the same infant was missed two weeks out. As a clot ages, the optical properties change as hemoglobin is metabolized. Thus, similar to MRI, optical scanning may provide a method for dating bleed age via an age-dependent signal. Further, alterations in local hemoglobin concentration and oxygenation near the site of the hemorrhagic events were found, raising the possibility that such signs accompany, and perhaps precede the hemorrhagic event. Such findings may allow for a degree of hemorrhage prediction. Supported by NIH N43-NS-4-2315 & RR-00081, ONR N-00014-94-1-1024, and the Spectros Corporation (equity held except by JVH, DKS).Table

Table 1
Full size table