Imaging devices, systems, and methods are provided. Some embodiments of the present disclosure are particularly directed to imaging a region of interest in tissue with photoacoustic and ultrasound modalities. In some embodiments, a medical sensing system includes one or more external optical emitters and a measurement apparatus configured to be placed within a vascular pathway. The one or more optical emitters and the measurement apparatus may be moved together synchronously. The measurement apparatus may be configured to receive sound waves created by the interaction between emitted optical pulses and tissue, and transmit and receive ultrasound signals. The medical sensing system may also include a processing engine operable to produce images of the region of interest and a display configured to visually display the image of the region of interest.