A portable, handheld device for fluorescence-based imaging is provided. The device comprises a wireless communication device having a sensor configured to detect optical signals. The device further comprises an assembly configured to receive and secure the wireless communication device therein. The assembly includes a housing, at least one light source coupled to the housing, a power supply, and an optical filter holder coupled to the housing and configured to receive one or more optical filters. An endoscope portion of the device is positioned relative to the sensor to visualize at least a portion of a confined anatomical space and to receive optical signals from a visualized, illuminated portion of a target positioned within the confined anatomical space. A processor of the device includes image analysis software and is configured to produce a composite representation of the illuminated portion of the target positioned within the confined anatomical space.
