BALTIMORE, April 30, 2007 -- In an advance that can potentially assist cancer diagnosis, a new optical technique provides high-resolution, three-dimensional images of blood vessels by taking advantage of the natural multiple-photon-absorbing properties of hemoglobin, the red-blood-cell molecule that carries oxygen throughout the bloodstream. The research will be presented in Baltimore at CLEO/QELS, May 6 May 11.
The new laser-based method, developed at Duke University, should provide 3-D images of blood vessels in relatively deep tissue (up to 1 mm, much better than conventional microscopes) with a resolution at the micron scale (at the level of blood cells, which is better than MRI resolution) and does not require any contrast agents or fluorescent markers (unlike most other high-resolution vessel-imaging techniques).
Clinically, the imaging technique can potentially be used to detect the spread of cancer, since angiogenesisthe growth of new blood vessels from existing onesoften signals the proliferation of tumors. This may make the technique convenient and powerful for helping to diagnose diseases such as melanoma, the deadliest form of skin cancer. The technique can image blood vessels up to a millimeter below the surface. Looking at blood vessels just below skin growths would be very useful for distinguishing between malignant and benign skin tumors, and would remove the critical need for skin biopsies, which is especially helpful if there are multiple suspicious areas that need to be investigated.
Since hemoglobin is highly concentrated in red blood cells, imaging the locations where this molecule occurs can map out the distribution of red blood cells and reveal the vessels themselves. If the imaging is fast enough, researchers can capture snapshots of blood flow in individual vessels. Moving beyond mere imaging, the technique can detect the difference between oxygen-carrying hemoglobin (oxyhemoglobin) and oxygen-lacking hemo
Contact: Colleen Morrison
Optical Society of America