title: Miniature probe integrating optical-resolution photoacoustic microscopy, optical coherence tomography, and ultrasound imaging: proof-of-concept.
abstract: In this Letter, we present a novel tri-modal miniature side-view probe, through which optical-resolution photoacoustic microscopy (OR-PAM), optical coherence tomography (OCT), and pulse-echo ultrasound (US) images can be coaxially acquired and displayed simultaneously. The probe consists of a common optical path for OR-PAM (light delivery) and OCT (light delivery/detection), and a 40-MHz unfocused ultrasound transducer for OR-PAM (photoacoustic detection) and US (ultrasound transmission/receiving) with an overall diameter of 2 mm. Combining OR-PAM, OCT, and US would provide complementary information including optical absorption (OR-PAM), optical back-scattering (OCT), and deep tissue structures (US) about biological tissue. Based on an integrated imaging system consisting of OR-PAM, time-domain OCT, and US, phantom images and in vivo images of rat ear were acquired to demonstrate the capabilities of the integrated tri-modality imaging probe. The probe yields a lateral resolution of 13.6 μm for OR-PAM and OCT, and an axial resolution of 43 μm for OR-PAM and US. Currently, for a scanning area of 1 ×1  mm, it took ∼25  min to acquire data for tri-modal volumetric imaging.
authors.forename: Xianjin
authors.initials: X
authors.lastname: Dai
authors.forename: Lei
authors.initials: L
authors.lastname: Xi
authors.forename: Can
authors.initials: C
authors.lastname: Duan
authors.forename: Hao
authors.initials: H
authors.lastname: Yang
authors.forename: Huikai
authors.initials: H
authors.lastname: Xie
authors.forename: Huabei
authors.initials: H
authors.lastname: Jiang
mesh_terms: D000818:Animals; D004423:Ear / Q000000981:diagnostic imaging; D008853:Microscopy / Q000379:methods*; D008904:Miniaturization / Q000379:methods*; D061088:Photoacoustic Techniques / Q000379:methods*; D051381:Rats; D018511:Systems Integration; D041623:Tomography, Optical Coherence / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*