Optoacoustic detection of intra- and extracranial hematomas in rats after blast injury.

Surgical drainage of intracranial hematomas is often required within the first four hours after traumatic brain injury (TBI) to avoid death or severe disability. Although CT and MRI permit hematoma diagnosis, they can be used only at a major health-care facility. This delays hematoma diagnosis and therapy. We proposed to use an optoacoustic technique for rapid, noninvasive diagnosis of hematomas. In this study we developed a near-infrared OPO-based optoacoustic system for hematoma diagnosis and cerebral venous blood oxygenation monitoring in rats. A specially-designed blast device was used to inflict TBI in anesthetized rats. Optoacoustic signals were recorded from the superior sagittal sinus and hematomas that allowed for measurements of their oxygenations. These results indicate that the optoacoustic technique may be used for early diagnosis of hematomas and may provide important information for improving outcomes in patients with TBI.