Noninvasive reflection mode photoacoustic imaging through infant skull toward imaging of neonatal brains

The feasibility of functional imaging of neonatal brains was studied in a noninvasive transcranial manner by using reflection mode photoacoustic technique for the first time. Experiments were conducted to examine the quality of photoacoustic signals and consequent images across a newborn infant skull. With the designed system, photoacoustic imagine, of blood vessels through the infant skull has been achieved with an axial resolution up to 50 mu m and a lateral resolution up to 420 mu m. Experimental results also indicate that photoacoustic imaging of neonatal brain with a depth of 21 mm or more beneath the skull is feasible when working with near-infrared light. Moreover, the performance of this technique for measuring and monitoring the changes in blood oxygenation level through the newborn infant skull has also been explored. This study suggests that reflection mode photoacoustic imaging holds promise to become a novel and powerful too] for noninvasive diagnosis, monitoring and prognosis of disorders in neonatal brains. (c) 2007 Elsevier B.V. All rights reserved.