All-optical ultrasound catheter for rapid B-mode oesophageal imaging

All-optical ultrasound (OpUS) is an imaging paradigm that uses light to both generate and receive ultrasound, and has progressed from benchtop to in vivo studies in recent years, demonstrating promise for minimally invasive surgical applications. In this work, we present a rapid pullback imaging catheter for side-viewing B-mode ultrasound imaging within the upper gastrointestinal tract. The device comprised an ultrasound transmitter configured to generate ultrasound laterally from the catheter and a plano-concave microresonator for ultrasound reception. This imaging probe was capable of generating ultrasound pressures in excess of 1 MPa with corresponding -6 dB bandwidths > 20 MHz. This enabled imaging resolutions as low as 45 & mu;m and 120 & mu;m in the axial and lateral extent respectively, with a corresponding signal-to-noise ratio (SNR) of 42 dB. To demonstrate the potential of the device for clinical imaging, an ex vivo swine oesophagus was imaged using the working channel of a mock endoscope for device delivery. The full thickness of the oesophagus was resolved and several tissue layers were present in the resulting ultrasound images. This work demonstrates the promise for OpUS to provide rapid diagnostics and guidance alongside conventional endoscopy.

Automated summary

All-optical ultrasound (OpUS) is a promising imaging technique that utilizes light to generate and receive ultrasound waves. In this study, a rapid pullback imaging catheter was developed for side-viewing B-mode ultrasound imaging in the upper gastrointestinal tract. The imaging probe achieved high-resolution imaging with ultrasound pressures exceeding 1 MPa and a signal-to-noise ratio (SNR) of 42 dB. Imaging of an ex vivo swine oesophagus demonstrated the potential of OpUS for rapid diagnostics and guidance in clinical settings alongside conventional endoscopy.