A new method for visualizing pulmonary artery microvasculature using synchrotron radiation pulmonary microangiography: the measurement of pulmonary arterial blood flow velocity in the high pulmonary blood flow rat model

Abstract

These novel results demonstrate that SRPA was useful in both visualizing the dynamic flow distribution within the microvasculature and calculating PBF velocity. This newly developed, non-invasive technology may become a powerful tool in clarifying the mechanism of vascular remodeling associated with high PBF-induced shear stress.

Large-view x-ray imaging for medical applications using the world’s only vertically polarized synchrotron radiation beam and a single asymmetric Si crystal

“…This technique is also performed at various other synchrotron radiation facilities. The use of detectors capable of high-speed imaging enables the observation of living organisms by angiography (Matsushita et al 2008, Konishi et al 2011, Umetani et al 2011, Fuji et al 2016, Miya et al 2017, and Torii et al 2017, Tokunaga et al 2018. Methods to reduce motion artifacts and carry out dynamic observations by improving computational algorithms have also been investigated (Wang et al 2020 andYu et al 2022).…”

“…Measurements with high temporal resolution have a field of view of only several millimeters, which is insufficient for viewing both sides of an organism (Umetani et al 2011, Torii et al 2017. In previous experiments, lapped Si crystals were applied to the double crystal monochromator instead of mechanochemical crystals to obtain sufficient x-ray intensity while maintaining a wide field of view for research purposes, and temporal resolution of tens of microseconds was obtained (Fuji et al 2016, Miya et al 2017and Tokunaga et al 2018. However, a lapped crystal is known to increase scattered x-rays and angular broadening of diffracted x-rays (Shiwaku et al 1991), which also degrade the spatial resolution of the image.…”

Sensitive imaging of intact microvessels in vivo with synchrotron radiation

“…Early stages of diseases, including stroke, hypertension, angiogenesis of tumours, spinal cord injuries, etc., are closely associated with the lesions of microvasculature (Ayala-Domínguez & Brandan, 2018;Cao et al, 2019;Gu et al, 2019;Guan et al, 2012;Kidoguchi et al, 2006;Kiessling et al, 2004;Li et al, 2019;Lin et al, 2015;Liu et al, 2010;Tokunaga et al, 2018;Umetani et al, 2007;Wang et al, 2017Wang et al, , 2019. Rodent models of human vascular diseases are extensively used for the preclinical investigation of the disease evolution and therapy.…”

“…A hybrid bismuth/carbon-nanotube contrast agent was successfully used to locate the labelled stem cells with X-ray imaging but in vivo studies with animal models are still required to evaluate the efficacy of this material (Herná ndez-Rivera et al, 2019). Furthermore, in vivo imaging of the rodent spinal cord microvasculature is a challenging task at present because of the significant movement artefacts from the adjacent lungs and heart (Cao et al, 2019;Tokunaga et al, 2018). A long circulating blood-pool contrast agent has been adopted for the in vivo microtomography of mouse cerebrovasculature and small vessels have been successfully delineated.…”