By combining two techniques, magnetic resonance imaging (MRI) and near-infrared optics, researchers at Dartmouth College and Dartmouth Medical School may have devised a new, potentially more accurate method for diagnosing breast cancer.
Their pilot study, demonstrating the feasibility of the concept, is published in the April 15 issue of the journal Optics Letters, published by the Optical Society of America.
The new technique utilizes MRI to produce an image of the breast, yielding information on its structure, including shape and composition. The near-infrared light technique provides information on how the tissue is functioning, for example, whether a region contains a large amount of blood and is rapidly consuming oxygen as early cancers typically do. The researchers are hoping this dual-procedure approach will be a key to learning which tissues are malignant before performing a biopsy.
The pilot study involved a 29-year-old woman with a ductal carcinoma, a very common breast cancer, in her left breast. A contrast MRI procedure was performed, where MRI was done before and after the contrasting agent gadolinium was injected. The area enhanced by the contrasting agent was targeted for the optical technique, known as near-infrared spectroscopy (NIRS). The results showed the area's hemoglobin level was high, oxygen saturation was low and water content was high, all indicators of cancerous tissue.
Recent advancements in medical imaging systems have focused on increasing the detail of anatomical images, but there has also been a growing interest in devices that provide information on tissue function. One of the difficulties with functional imaging has been that most of these devices have low spatial resolution. The structural information from the MR image helps guide the NIRS technique to the regions of interest so that the two can together create high-resolution, functional images of breast cancer.
The American Cancer Society recently recommended MRI screening for patients at high risk of developing breast cancer in their lifetimes. Researchers believe that this new dual-procedure technique may potentially aid in cancer diagnosis.