Infrared imaging devices are provided which are configured to implement side-scan infrared imaging for, e.g., medical applications. For example, an imaging device includes a ring-shaped detector element comprising a circular array of infrared detectors configured to detect thermal infrared radiation, and a focusing element configured to focus incident infrared radiation towards the circular array of infrared detectors. The imaging device can be an ingestible imaging device (e.g., swallowable camera) or the imaging device can be implemented as part of an endoscope device, for example.
