Optically-excited simultaneous photoacoustic and ultrasound imaging based on a flexible gold-PDMS film

Abstract

We constructed a flexible gold-polydimethylsiloxane (gold-PDMS) nanocomposites film with controllable thickness and light transmittance, to realize optically-excited simultaneous photoacoustic (PA) and ultrasound (US) imaging under a single laser pulse irradiation. Benefiting from the excellent thermoelastic properties, the gold-PDMS film absorbs part of the incident laser energy and produces a high-intensity US, which is used to realize US imaging. Meanwhile, the partly transmitted light is used to excite samples for PA imaging. By controlling the thickness of the gold-PDMS, we can control the center frequency in the US imaging. We experimentally analyzed the frequency of the produced US signal by the gold-PDMS film and compared it with the finite element analysis (FEA) method, where the experiments agree with the FEA results. This method is demonstrated by the experiments on phantoms and a mouse model. Our work provides a cost-effective methodology for simultaneous PA and US imaging.

PDMS Composites with Photostable NIR Dyes for B-Mode Ultrasound Imaging

“…Composite coatings comprising elastomeric and absorbing components have emerged as efficient optical transducers. A wide variety of absorbers have been studied, including metallic nanostructures [1,7], graphene [8], candle soot [9,10] and carbon nanotubes [11][12][13]. Typically, polydimethlysiloxane (PDMS) is used as an elastomeric host component due to its large thermal expansion coefficient, which provides efficient photoacoustic conversion [1,8,10,14].…”

“…Here, the ultrasound can be generated at one wavelength via optical absorption within the coating, whilst at other wavelengths light can be transmitted through the coating and be used for a complementary modality such as photoacoustic imaging [7,18] or ablation [14].…”

PDMS composites with photostable NIR dyes for multi-modal ultrasound imaging

“…All-optical ultrasound imaging has emerged as an imaging paradigm well-suited for minimally invasive surgical procedures [1][2][3]. With this modality, ultrasound is generated when pulsed or modulated light is absorbed within a composite coating material [4][5][6][7][8]. Using optical fibres to deliver light for ultrasound generation and reception allows complementary therapeutic and imaging modalities to be integrated to create highly miniaturised devices [1,4,9,10].…”

“…With this modality, ultrasound is generated when pulsed or modulated light is absorbed within a composite coating material [4][5][6][7][8]. Using optical fibres to deliver light for ultrasound generation and reception allows complementary therapeutic and imaging modalities to be integrated to create highly miniaturised devices [1,4,9,10]. One area of interest for these devices is combined imaging and optical ablation, to provide real-time monitoring of ablation lesion depth.…”

“…One area of interest for these devices is combined imaging and optical ablation, to provide real-time monitoring of ablation lesion depth. However, combining modalities requires carefully engineered composite materials with wavelength-selective absorption [ 1 , 4 , 9 , 10 ]. Previous research has demonstrated the use of crystal violet dye or gold nanoparticles embedded in a polydimethylsiloxane (PDMS) host for co-registered ultrasound and photoacoustic imaging [ 1 ].…”