Photoacoustic tomography (PAT) may provide better, deeper imaging photographs and improve patient care--without the health hazards associated with X-rays.
That's the upshot of a study recently published in Science by researchers from Washington University in St. Louis. PAT enables users to take images deeper in the body than more conventional forms of imaging and to form images that are clearer and multicolored due to light absorption by colored molecules, such as hemoglobin. X-rays also can take deep images, but they're harder to read and pump radiation into the patient.
"The trick of photoacoustic tomography is to convert light absorbed at depth to sound waves, which scatter a thousand times less than light, for transmission back to the surface," an announcement for the study from the school says. "The tissue to be imaged is irradiated by a nanosecond-pulsed laser at an optical wavelength. Absorption by light by molecules beneath the surface creates a thermally induced pressure jump that launches sound waves that are measured by ultrasound receivers at the surface and reassembled to create what is, in effect, a photograph."
According to the researchers, PAT has the potential to detect cancer earlier, spot lesions that are deeper in the body, and enable physicians to use needle biopsies instead of surgical procedures, according to a recent article in Diagnostic Imaging.
The industry has expressed concern about the radiation risks inherent in certain forms of imaging and has questioned whether the risks outweigh the benefits. PAT may prove to be not only a better imaging technique, it may be a safer one.
"Right now this technology is growing exponentially, so obviously there's still a lot to do," Lihong V. Wang, Ph.D., the study's lead author, told Medscape Medical News. "In my opinion, the priority is to demonstrate and validate this technology in the clinic, which is what we're doing right now, and convert this technology to commercial products so it will get into the hands of radiologists and physicians."