Abstract: A radial scanner configured to image the interior of a tube includes, in an embodiment, a housing having a transparent window, a photo-sensing array, a mirror located within the housing and oriented to direct an image around a circumference of an interior surface of the tube outside the transparent window to the photo-sensing array, and a light source configured to illuminate the interior surface of the tube, wherein the photo-sensing array is configured to receive the image around the circumference as a circular line scan. In an embodiment, the radial scanner is deployed as an ingestible capsule. In another embodiment, the radial scanner is deployed as a fiber optic catheter.