A diagnostic imaging catheter is disclosed, which is capable of preventing a solution from an internal space of a hub from flowing into a portion communicating with the internal space of the hub and to which the signal lines such as the optical fiber and the electric signal cable are electrically or optically connected. The optical diagnostic catheter includes a rotatable drive shaft, an elongated sheath configured to be inserted into a biological lumen, a hub that includes a port connected to the sheath for supplying the solution, a connector portion that includes an optical connector accommodated in an internal space of the hub and optically connected to an external optical connector, a first seal portion that prevents the solution from the port from flowing into a first connection portion, and a second seal portion that prevents the solution from the port from flowing into a second connection portion.
