1. An imaging apparatus including: an elongated body having proximal and distal ends, the elongated body including a plurality of optical fibers extending lengthwise along the elongated body, and a plurality of longitudinally spaced apart imaging portions along at least a portion of the body, an individual one of the imaging portions including: an optical-to-acoustic transducer, configured to generate acoustic energy for imaging a region in response to a first optical signal in the optical fiber; and an acoustic-to-optical transducer, configured to sense acoustic energy from the region and to provide a responsive modulation of a second optical signal in the optical fiber.