Medinews, July 17, 2007 GALVESTON - Scientists are reporting new developments toward expanding the medical use of the laser optoacoustic imaging system (LOIS), an innovative new imaging technology that could ultimately join computed tomography (CT), magnetic resonance imaging (MRI), and other major diagnostic technologies.  In an article published in the July issue of American Chemical Society's (ACS) journal, Nano Letters, Dr. Massoud Motamedi and colleagues from the University of Texas Medical Branch (UTMB; Galveston, TX, USA) explained that LOIS uses a laser beam and ultrasound to detect early-stage cancer. LOIS, they noted, has advantages over traditional optical and ultrasound imaging methods in being able to "see" deep into the body and reveal diseased tissue. Use of LOIS, however, has been limited by lack of a suitable contrast agent, a compound that can be injected into the body to make diseased tissues even more visible during the imaging session.  The UTMB researchers study involved imaging laboratory mice with LOIS before and after an injection of gold nanorods, tiny rod-shaped clusters of gold atoms that are being assessed by other investigators for uses ranging from carriers for cancer-treatment drugs to digital data storage. Very low concentrations of the nanorods effectively enhanced the LOIS images, revealed deep tissues that cannot be seen with other imaging techniques.  This deep insight, combined with the ability to attach gold nanorods to monoclonal antibodies that specifically target cancer cells, may provide a promising new approach to early detection of cancer, the researchers reported.