Photoacoustic and thermoacoustic tomography with both optical and electrical contrasts
The absorption of electromagnetic energy causes thermal expansion and induces acoustic waves in biological tissues. Various tissues present particular characteristics in their absorption spectra. To acquire both photoacoustic and thermoacoustic images with multiple contrasts that reflect the absorption of electromagnetic energy, biological tissues are stimulated using laser and microwave pulses, respectively. Muscles with a rich blood supply strongly absorb green optical radiation, which provides excellent optical contrast. High water content tissues, such as connective tissue and muscle tissue, display high contrast to fatty tissues when imaged using microwave radiation. Most cancerous tissues have higher water and ionic concentrations, two characteristics that are also associated with angiogenesis and hemoglobin oxygen saturation. Therefore, cancer diagnosis based on information from tissue properties over an electromagnetic spectrum from microwave to optical bands can be more accurate than was previously available.
Additional Information© 2006 Society of Photo-optical Instrumentation Engineers (SPIE). We thank Meng-Lin Li, Jung-Taek Oh and Xueyi Xie, Ryan Lawless, Xing Jin and Manojit Pramarik for assistance on photoacoustic and thermoacoustic tomography, respectively.
Published - 608618.pdf