Flow-mediated dilatation test using optoacoustic imaging: a proof-of-concept

Abstract

Label-free multispectral optoacoustic tomography (MSOT) has recently shown superior performance in visualizing the morphology of human vasculature, especially of smaller vessels, compared to ultrasonography. Herein, we extend these observations towards MSOT interrogation of macrovascular endothelial function. We employed a real-time handheld MSOT scanner to assess flow-mediated dilatation (FMD), a technique used to characterize endothelial function. A data processing scheme was developed to quantify the dimensions and diameter changes of arteries in humans and determine wall distensibility parameters. By enabling high-resolution delineation of the blood-vessel wall in a crosssectional fashion, the findings suggest MSOT as a capable alternative to ultrasonography for clinical FMD measurements.

Non-invasive Measurement of Brown Fat Metabolism Based on Optoacoustic Imaging of Hemoglobin Gradients

“…Even though hemoglobin has long been recognized as a source of contrast for NIR spectroscopy and diffuse optical tomography (Ntziachristos et al, 2005), the poor resolution of these techniques has limited the accuracy and the range of reliable applications (Ntziachristos, 2010). Hemoglobin is also employed in optoacoustic (photoacoustic) imaging to visualize blood vessels and microvasculature (Karlas et al, 2017;Taruttis and Ntziachristos, 2015). Conversely, by applying macroscopic optoacoustic imaging in the NIR, we resolved not only vasculature but also general tissue features and related, for the first time, highresolution tissue hemoglobin readings in metabolic measurements of brown fat, confirmed by IC.…”

Hand-held optoacoustic imaging: A review

“…For OACT, arrays of piezoelectric ultrasound transducer elements are used, of which there are three geometries: linear, cylindrical, and spherical. Linear and cylindrical piezoelectric ultrasound transducer arrays are typically used for two-dimensional imaging, and spherical piezoelectric ultrasound transducer arrays are used for three-dimensional imaging [ 73 , 77 , 78 ]. The axial resolution of each array type is a function of the frequency response of the array.…”

“…In recent years, much energy has been devoted to researching and developing hand-held OAI platforms across the spectrum of OAI methods [ 14 , 16 , 21 , 33 , 34 , [36] , [37] , [38] , 46 , 62 , [67] , [68] , [69] , [72] , [73] , [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , [87] , [88] , [89] , [90] , [91] , [92] , [93] , [94] , [95] , [96] , [97] , [98] , [99] ]. These efforts are summarized in Table 1 .…”

Photoacoustic assessment of hemodynamic changes in foot vessels

“…It can afford high resolution images in deep tissue based on optical absorption. PAT has shown its ability in breast cancer [21][22][23], thyroid cancer [24,25], vascular examination [4,[26][27][28][29], inflammatory arthritis and osteoarthritis [30][31][32], oral cancer [33][34][35], bone pathology [36] and dermatology [37][38][39] in human studies. PAT of vasculature can be achieved because hemoglobin is concentrated in blood vessels with strong optical absorption.…”