Flow tracing microparticle sensors designed for enhanced X-ray contrast

“…Previous work has demonstrated the ability to perform X-ray velocimetry on whole blood without the addition of tracer particles by utilising phase contrast imaging, 19,21,28 but the relatively small phase difference between RBCs and the surrounding tissue renders this technique impractical for in vivo studies. Other studies have recently developed bio-compatible microcapsules; 22,26 however, there is yet to be published work using these microcapsules for X-ray velocimetry. Alternatively, commercially available ultrasound contrast agent has been used to seed blood for use in the newly developed technique: computer tomographic X-ray velocimetry (CTXV).…”

Section: Introductionmentioning

confidence: 98%

X-ray Velocimetry and Haemodynamic Forces Within a Stenosed Femoral Model at Physiological Flow Rates

et al. 2011

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High resolution in vivo velocity measurements within the cardiovascular system are essential for accurate calculation of vessel wall shear stress, a highly influential factor for the progression of arterial disease. Unfortunately, currently available techniques for in vivo imaging are unable to provide the temporal resolution required for velocity measurement at physiological flow rates. Advances in technology and improvements in imaging systems are allowing a relatively new technique, X-ray velocimetry, to become a viable tool for such measurements. This study investigates the haemodynamics of pulsatile blood flow in an optically opaque in vitro model at physiological flow rates using X-ray velocimetry. The in vitro model, an asymmetric stenosis, is designed as a 3:1 femoral artery with the diameter and flow rate replicating vasculature of a mouse. Velocity measurements are obtained over multiple cycles of the periodic flow at high temporal and spatial resolution (1 ms and 29 μm, respectively) allowing accurate measurement of the velocity gradients and calculation of the wall shear stress. This study clearly illustrates the capability of in vitro X-ray velocimetry, suggesting it as a possible measurement technique for future in vivo vascular wall shear stress measurement.

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“…The amount of encapsulated Iopamidol in each particle was detected by energy dispersive X‐ray spectroscopy (EDS) connected with SEM and the values were averaged with five randomly selected particles. The Iopamidol encapsulation was also determined together with the degree of crosslinking using proton nuclear magnetic resonance ( 1 H NMR; 500 MHz Bruker DRX500 at 30 °C in deuterated dimethyl sulfoxide solvent), where the chemical shifts of the designed particles were compared with those of the empty capsule, uncrosslinked PVA, pure Iopamidol and GA .…”

Section: Methodsmentioning

confidence: 99%

Imaging efficiency of an X‐ray contrast agent‐incorporated polymeric microparticle

Ahn

Jung

Lee

et al. 2011

Contrast Media & Molecular

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Biocompatible polymeric encapsulants have been widely used as a delivery vehicle for a variety of drugs and imaging agents. In this study, X-ray contrast agent (iopamidol) is encapsulated into a polymeric microparticle (polyvinyl alcohol) as a particulate flow tracer in synchrotron X-ray imaging system. The physical properties of the designed microparticles are investigated and correlated with enhancement in the imaging efficiency by experimental observation and theoretical interpretation. The X-ray absorption ability of the designed microparticle is assessed by Beer-Lambert-Bouguer law. Particle size, either in dried state or in solvent, primarily dominates the X-ray absorption ability under the given condition, thus affecting imaging efficiency of the designed X-ray contrast flow tracers.

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Flow tracing microparticle sensors designed for enhanced X-ray contrast

Cited by 22 publications

References 26 publications

X-ray-Computed Tomography Contrast Agents

X-ray-Computed Tomography Contrast Agents

X-ray Velocimetry and Haemodynamic Forces Within a Stenosed Femoral Model at Physiological Flow Rates

Imaging efficiency of an X‐ray contrast agent‐incorporated polymeric microparticle

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