Simultaneous Molecular and Hypoxia Imaging of Brain Tumors In Vivo Using Spectroscopic Photoacoustic Tomography

• Published in: Proceedings of the IEEE Vol. 96; no. 3; pp. 481 - 489
• Main Authors: Li, Meng-Lin, Oh, Jung-Taek, Xie, Xueyi, Ku, Geng, Wang, Wei, Li, Chun, Lungu, Gina, Stoica, George, Wang, Lihong V.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2008; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biomedical materials; Biomedical optical imaging; Contrast agents; Functional imaging; Hemoglobin; hemoglobin oxygen saturation; High-resolution imaging; Humans; Imaging; In vivo; In vivo tests; molecular imaging; Neoplasms; Optical imaging; Optical saturation; Spatial resolution; spectroscopic photoacoustic tomography; Spectroscopy; Surgical implants; total hemoglobin concentration; Tumors; Ultrasonic imaging; molecular imaging; hemoglobin oxygen saturation; spectroscopic photoacoustic tomography; total hemoglobin concentration; Functional imaging
• ISSN: 0018-9219; 1558-2256
• DOI: 10.1109/JPROC.2007.913515

Noninvasive molecular and functional imaging in vivo is promising for detecting and monitoring various physiological conditions in animals and ultimately humans. To this end, we present a novel noninvasive technology, spectroscopic photoacoustic tomography (SPAT), which offers both strong optical absorption contrast and high ultrasonic spatial resolution. Optical contrast allows spectroscopic separation of signal contributions from multiple optical absorbers (e.g., oxyhemoglobin, deoxyhemoglobin, and a molecular contrast agent), thus enabling simultaneous molecular and functional imaging. SPAT successfully imaged with high resolution the distribution of a molecular contrast agent targeting integrin overexpressed in human U87 glioblastomas in nude mouse brains. Simultaneously, SPAT also imaged the hemoglobin oxygen saturation and the total hemoglobin concentration of the vasculature, which revealed hypoxia in tumor neovasculature. Therefore, SPAT can potentially lead to better understanding of the interrelationships between hemodynamics and specific biomarkers associated with tumor progression.