A Transparent Ultrasound Array for Real-Time Optical, Ultrasound, and Photoacoustic Imaging

Abstract

Objective and Impact Statement. Simultaneous imaging of ultrasound and optical contrasts can help map structural, functional, and molecular biomarkers inside living subjects with high spatial resolution. There is a need to develop a platform to facilitate this multimodal imaging capability to improve diagnostic sensitivity and specificity. Introduction. Currently, combining ultrasound, photoacoustic, and optical imaging modalities is challenging because conventional ultrasound transducer arrays are optically opaque. As a result, complex geometries are used to coalign both optical and ultrasound waves in the same field of view. Methods. One elegant solution is to make the ultrasound transducer transparent to light. Here, we demonstrate a novel transparent ultrasound transducer (TUT) linear array fabricated using a transparent lithium niobate piezoelectric material for real-time multimodal imaging. Results. The TUT-array consists of 64 elements and centered at ~6 MHz frequency. We demonstrate a quad-mode ultrasound, Doppler ultrasound, photoacoustic, and fluorescence imaging in real-time using the TUT-array directly coupled to the tissue mimicking phantoms. Conclusion. The TUT-array successfully showed a multimodal imaging capability and has potential applications in diagnosing cancer, neurological, and vascular diseases, including image-guided endoscopy and wearable imaging.

Dissecting Multiparametric Cerebral Hemodynamics using Integrated Ultrafast Ultrasound and Multispectral Photoacoustic Imaging

“…While B-mode US frame shows mechanical impedance contrast based anatomical information of the tissue, B-mode PA frame displays optical absorption contrast based molecular information of the tissue. Since both B-mode US and PA frames are acquired using the same UST probe, a co-registered US+PA (USPA) frame with overlaid anatomical and optical contrasts is helpful to understand the origin of PA signals [17, 65]. After acquiring each USPA frame data, the Vantage was set to idle to wait for the laser trigger pulse (Fig.…”

“…S4a) were dyed with India ink, and then positioned ∼ 5 mm and 4 mm apart from each other on the axial and lateral planes, respectively. Then a solution mixture of agar, intralipid, and silica beads with a respective weight ratio of 1.5%, 1%, and 1% was poured into the tank to provide the ultrasound background speckles as well as the optical scattering [65]. While ultrasound imaging contrast of the phantom was based on the acoustic impedance differences between the wire and the background, the photoacoustic imaging contrast was based on the light absorption of metal wire targets dyed with India ink.…”

An Emerging Era: Conformable Ultrasound Electronics

“…This enables multimodal imaging, which can help clinicians make more accurate diagnoses and guide interventions. [317] Recently, several flexible arrays with photoacoustic functions were proposed, including an A-line photoacoustic signal from the flexible transducer array, [318] a flexible array transducer for photoacoustic-guided interventions, [319] a PVDF-based transparent flexible transducer for a photoacoustic imaging system, [320] and a flexible array transducer for photoacoustic-guided surgery. [321] For example, Jiang et al proposed a hybrid-induced energy transfer strategy using photoacoustic and piezo-ultrasound technology in a 3D twining wireless implant for stable powering and high-resolution signal communication.…”

Photoacoustic imaging for microcirculation

“…Reprinted with permission 148 versatility and cost effectiveness. [170][171][172][173][174][175][176] For example, Chen et al thinned-skull window. 179,180 The TUT cranial window allowed us to use three different modalities OR-PAM, TPM, and IOSI to image awake mouse brain vasculature using a head restraint setup.…”