New Advance in Instrumentation for Optical Mammography
Researchers from Italy replace photomultiplier tubes with silicon and see a thousandfold rise in sensitivity
Optical mammography uses near-infrared light instead of X-rays to probe breast tissue and is being developed as an alternative to traditional mammography. The novel technique has certain advantages, such as a lack of harmful ionizing radiation and the application of only gentle pressure on the breast rather than strong compression.
However, the major drawback of optical mammography to date has been its poor spatial resolution. In a newly presented study, researchers from the Polytechnic University of Milan have achieved an advance in instrument development that increases the sensitivity of optical mammography by up to a thousandfold. The results were presented April 4 at the OSA Biophotonics Congress meeting held in Hollywood, Florida.
Optical mammography devices consist of multiple laser sources and detectors that gather information about the optical properties of breast tissue. The technique measures blood volume and oxygenation, as well as lipid, water and collagen content.
The novel instrument replaces two photomultiplier tubes with a detection chain based on newer solid-state technology. The probe is made up of eight silicon photomultipliers -- a matrix of hundreds to thousands of cells that each hold a single-photon counting detector -- mounted in a square pattern that sits near the compression plate. The resulting device has increased sensitivity, provides more robust data, and is cheaper to manufacture.
The researchers performed preliminary experiments with 32 solid phantoms that covered a wide range of absorption and scattering properties, finding that the new detection chain increases the optical sensitivity up to a factor of 1,000. The encouraging results have prompted them to plan human studies to test the instrument's performance in real clinical conditions.