Photoacoustic catheter and imaging system using same

A method of obtaining optical data and ultrasonic data within a mammalian luminal organ using a photoacoustic catheter, the photoacoustic catheter including an elongated catheter body and a housing positioned near a distal end of the elongated catheter body,

• a length of multimode fiber extending through the elongated catheter body and terminating in the housing, an ultrasonic transducer positioned at least partially within the housing,
• and a mirror element positioned at least partially within the housing and including a mirror surface, the method including steps of:
• introducing at least a portion of the photoacoustic catheter into the mammalian luminal organ;
• transmitting an optical wave from the multimode fiber and toward the mirror surface of the mirror element;
• transmitting an ultrasonic wave from the ultrasonic transducer and toward a distal end of the multimode fiber;
• redirecting the ultrasonic wave from the distal end of the multimode fiber and toward the mirror surface of the mirror element;
• and
• redirecting the optical wave and the ultrasonic wave from the mirror surface and collinearly from the housing and out of an aperture through the housing to obtain the optical data and the ultrasonic data within the mammalian luminal organ.

An imaging system including a photoacoustic catheter, the photoacoustic catheter including an elongated catheter body and a housing positioned near a distal end of the elongated catheter body, a length of multimode fiber extending through the elongated catheter body and terminating in the housing, an ultrasonic transducer positioned at least partially within the housing, and a mirror element positioned at least partially within the housing and including a mirror surface, the imaging system including:

• an optical excitation source operatively connected to the photoacoustic catheter via the multimode fiber to deliver an optical wave;
• a pulser/receiver operatively connected to the photoacoustic catheter via the ultrasonic transducer to deliver an ultrasonic wave, wherein the ultrasonic wave is delivered from the ultrasonic transducer to a distal end of the multimode fiber, and the ultrasonic wave is redirected from the distal end of the multimode fiber to the mirror surface of the mirror element;
• whereby the photoacoustic catheter delivers the optical wave and the ultrasonic wave collinearly through the housing and the optical wave and the ultrasonic wave are redirected from the mirror surface of the mirror element out of the aperture to obtain optical data and ultrasonic data within a mammalian luminal organ;
• whereby a signal from the optical wave and a signal from the ultrasonic wave are detected by the ultrasonic transducer and received by the pulser/receiver;
• and
• a data acquisition device operatively connected to the photoacoustic catheter via the pulser/receiver to digitize the signals received at the pulser/receiver.