Abstracts

Photoacoustic tomography (PAT) is an emerging imaging modality that has the potential to image the dynamic function of the brain due to its unique ability of imaging biological tissues with high optical contrast and ultrasound resolution. Here we report the first application of our finite element based PAT method for imaging of seizure-onset zone in an animal model of focal seizures., Male Harlen Sprague-Dawley rats, weighing 50[sim]60g, were used in this study. The rats were anesthetized with urethane 1mg/g in all the experiments. Focal seizures were induced by microinjection of a GABA[sub]A[/sub] antagonist bicuculline methiodide (BMI) into the left parietal neocortex. A mechanical scanning photoacoustic system with single acoustic transducer was employed for collecting the light-induced acoustic signals. A reconstruction algorithm was used to generate PAT images., Following microinjection of BMI into the left parietal cortex, focal seizures were induced and confirmed with electroencephalogram recordings which showed high amplitude spike and wave discharges. These seizures were accurately localized tomographically by PAT. The dynamic changes in PAT imagings were comparable to EEG changes during seizures., Our result showed that PAT is an emerging non-invasive imaging modelity to localize the seizure-onset zone. Compared to other neuroimaging modalities, PAT has not only the advantage of high spatial and temporal resolution, but also the ease of use. It has the potential to bring brain imaging to the bedside, clinic and daily life, and coincide a scan with a seizure such that an epileptic focus and seizure occurrence can be visualized in real-time., (Supported by: This work was supported in part by the National Institutes of Health (R01 AR048122) and Wilder Epilepsy Research Center of the University of Florida.)