A gigapixel camera that takes high-resolution snapshots of the entire body could be a simple new tool for whole-body skin cancer screening. It is essentially three dozen cameras in one and allows researchers to image the whole body down to a freckle. This research was presented at the Optical Society (OSA) 98th Annual Meeting, Frontiers in Optics, in Tucson, Arizona.
Melanoma is the fifth most common cancer type in the United States, and it is also the deadliest form of skin cancer, causing more than 75% of skin-cancer deaths. If caught early enough though, the disease is almost always curable.
“The camera is designed to find lesions potentially indicating skin cancers on patients at an earlier stage than current skin examination techniques,” said coauthor Daniel Marks, PhD, of Duke University in Durham, North Carolina. “Normally a dermatologist examines either a small region of the skin at high resolution or a large region at low resolution, but a gigapixel image doesn’t require a compromise between the two.”
Although whole-body photography has already been used to identify melanomas and exclude nondangerous stable lesions, the approach is typically limited by the resolution of the cameras used. A commercial camera with a wide-angle lens can easily capture an image of a person’s entire body, but it lacks the resolution needed for a dermatologist to zoom in on one tiny spot. So dermatologists typically examine suspicious lesions with digital dermatoscopy, which is a technique to evaluate the colors and microstructures of suspicious skins not visible to the naked eye. The need for two types of images drives up costs and limits possibilities for telemedicine.
The gigapixel camera developed by the Duke University team solves this problem by essentially combining 34 microcameras into one. With a structure similar to a telescope and its eyepieces, the camera combines a precise but simple objective lens that produces an imperfect image with known irregularities.
The 34 microcameras are arranged in a dome to correct these aberrations and form a continuous image of the scene. The exposure time and focus for each microcamera can be adjusted independently, and a computer can do a preliminary examination of the images to determine if any areas require future attention by the specialists.
Marks pointed out that although the resolution of the gigapixel camera is not as high as the best dermatoscope, it is significantly better than normal photography, allows for a larger imaging area than a dermatoscope, and could be used for telemedicine. This possibility could make the routine screening available to a larger number of people, even in remote locations.
Although the camera’s effectiveness still needs to be proven in clinical trials before becoming routinely available to patients, the researchers have gathered enough preliminary data on a healthy volunteer to demonstrate that it has adequate resolution and field of view needed for skin disease screening. The next step, they say, is to test how well it works in the clinic.