Though dermatologists are trained to analyze the surface of the skin, there’s a lot going on just a millimeter below the surface – that can’t be seen by the naked eye. Cancerous lesions feature characteristic anatomies that can be identified for diagnostic purposes, but seeing the 3D structure of tiny blood vessels below the skin has been challenging. Now a team from Medical University Vienna in Austria and the Ludwig-Maximilians University in Munich, Germany have developed an optical coherence tomography (OCT) technique that employs a near-infrared laser to visualize the micro-vessel structure just below the surface.
They were able to describe basic characteristic differences between healthy skin, dermatitis (dilated vessels and increased perfusion) and carcinoma (dense network of unorganized vessels with larger ones close to the surface). The technology may soon be available to dermatologists for in-office diagnostics.
From the announcement by the Optical Society (OSA):
The team’s images of basal cell carcinoma showed a dense network of unorganized blood vessels, with large vessels abnormally close to the skin surface. The larger vessels branch into secondary vessels that supply blood to energy-hungry tumor regions. The images, together with information about blood flow rates and tissue structure, could yield important insights into the metabolic demands of tumors during different growth stages.
The imaging system shows the most promise for clinical application in the diagnosis and treatment of skin cancer, the researchers believe. “We hope that improved in-depth diagnosis of tissue alterations due to disease might help to reduce the number of biopsies by providing better guidance,” says Leitgeb. The system could also be used by doctors to assess how quickly a tumor is likely to grow and spread, as well as to monitor the effectiveness of treatments such as topical chemotherapy. “Treatment monitoring may also be expanded toward inflammatory and auto-immune related dermatological conditions,” Blatter notes.
Going forward, the researchers would like to increase the field of view of the device so that they can image the full lesion along with its border to healthy tissue. They are also working on speeding up the post-processing of the optical signal to enable live vasculature display, and improving the portability of the system, which currently occupies an area about half the size of an office desk.
Study abstract in Biomedical Optics Express: In situ structural and microangiographic assessment of human skin lesions with high-speed OCT