Multimodal Contrast Agents for Optoacoustic Brain Imaging in Small Animals

Abstract

Optoacoustic (photoacoustic) imaging has demonstrated versatile applications in biomedical research, visualizing the disease pathophysiology and monitoring the treatment effect in an animal model, as well as toward applications in the clinical setting. Given the complex disease mechanism, multimodal imaging provides important etiological insights with different molecular, structural, and functional readouts in vivo. Various multimodal optoacoustic molecular imaging approaches have been applied in preclinical brain imaging studies, including optoacoustic/fluorescence imaging, optoacoustic imaging/magnetic resonance imaging (MRI), optoacoustic imaging/MRI/Raman, optoacoustic imaging/positron emission tomography, and optoacoustic/computed tomography. There is a rapid development in molecular imaging contrast agents employing a multimodal imaging strategy for pathological targets involved in brain diseases. Many chemical dyes for optoacoustic imaging have fluorescence properties and have been applied in hybrid optoacoustic/fluorescence imaging. Nanoparticles are widely used as hybrid contrast agents for their capability to incorporate different imaging components, tunable spectrum, and photostability. In this review, we summarize contrast agents including chemical dyes and nanoparticles applied in multimodal optoacoustic brain imaging integrated with other modalities in small animals, and provide outlook for further research.

Multimodal optoacoustic imaging: methods and contrast materials

“…235 More recently, the unique advantages of OA imaging are fostering the development of dedicated contrast materials with physical, chemical, and biochemical characteristics tailored to specific applications. 18,232,235,236 Dissemination of OA imaging systems among biomedical researchers helps crystallizing the key advantages and limitations of this modality with respect to alternative imaging methods, thus reinforcing the need for developing multimodal OA imaging approaches.…”

“…235 More recently, the unique advantages of OA imaging are fostering the development of dedicated contrast materials with physical, chemical, and biochemical characteristics tailored to specific applications. 18,232,235,236 Dissemination of OA imaging systems among biomedical researchers helps crystallizing the key advantages and limitations of this modality with respect to alternative imaging methods, thus reinforcing the need for developing multimodal OA imaging approaches. Here we provide a detailed description of the benefits and challenges associated with state-of-the-art multi-modality systems, contrast materials, and respective applications, including the combinations of OA with US, FL, OCT, Raman, MRI, CT, SPECT, and PET imaging.…”

Knowledge domain and dynamic patterns in multimodal molecular imaging from 2012 to 2021: A visual bibliometric analysis

“…Exogenous contrast agents, chemical dyes, and all kinds of nanostructures (carbon nanomaterials, gold nanomaterials, transition metal dichalcogenides, etc) are extensively studied recently. [49][50][51] As shown in Table 4, nanoparticles, contrast agents, and nanocrystals have high occurrence and total link strength.…”

Clinical photoacoustic/ultrasound dual-modal imaging: Current status and future trends

“…In order to enable molecular PAT/US detection, contrast agents can be specifically tailored to molecular targets of relevance to tumor metastasis, including those biomarkers expressed during lymphangiogenesis, as well as those expressed by tumors. Studies on exogenous contrast agents for PAT/US imaging biomedical application have been reported ( Kim et al, 2010a ; Xu et al, 2010 ; Jeon and Kim, 2014 ; Paproski et al, 2016 ; Zhang et al, 2016 ; Bayer et al, 2017 ; Park et al, 2017b ; Chitgupi and Lovell, 2018 ; Shi et al, 2021 ). Angiogenesis, the formation of new blood vessels, is a hallmark of many diseases, including tumor and inflammation.…”