Dispersive Transport of Angiographic Contrast During Antegrade Arterial Injection

Hao, Qing; Lieber, Baruch B.

doi:10.1007/s13239-012-0090-x

Cited by 3 publications

(5 citation statements)

References 14 publications

(16 reference statements)

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“…We use a constant diffusion coefficient D Diff CA;Blood ¼ 5 Â 10 À9 m 2 =s for binary molecular diffusion of CA in blood. 21 CA-transport through the microvasculature was not considered, since strong dispersion in the capillary bed arising from the wide variety of path lengths, results in effectively vanishing fluoroscopic venous CA-signals.…”

Section: Patient-specific Vascular Network Modelmentioning

confidence: 99%

“…The time of CA-arrival CA ToA (s) is the elapsed time between injection start and the instant when 10% of the local peak concentration value CA max (-) is reached. The slope CA s (s 21 ) is defined as the maximum time derivative of c(x,t) (-) upon CA-arrival. To eliminate the effect of CA dilution at converging branching points, we also compute the ''dilution-free'' slope CA s;disp ¼ CA s =CA max (s 21 ).…”

Section: Data Analysis and Diagnostic Parametersmentioning

confidence: 99%

“…The slope CA s (s 21 ) is defined as the maximum time derivative of c(x,t) (-) upon CA-arrival. To eliminate the effect of CA dilution at converging branching points, we also compute the ''dilution-free'' slope CA s;disp ¼ CA s =CA max (s 21 ). These values are determined at the nodes of computational models and on a pixel-by-pixel basis in DSA images.…”

Section: Data Analysis and Diagnostic Parametersmentioning

confidence: 99%

See 2 more Smart Citations

Hemodynamic Characterization of Peripheral Arterio-venous Malformations

et al. 2017

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Peripheral arterio-venous malformations (pAVMs) are congenital vascular anomalies that require treatment, due to their severe clinical consequences. The complexity of lesions often leads to misdiagnosis and ill-planned treatments. To improve disease management, we developed a computational model to quantify the hemodynamic effects of key angioarchitectural features of pAVMs. Hemodynamic results were used to predict the transport of contrast agent (CA), which allowed us to compare our findings to digital subtraction angiography (DSA) recordings of patients. The model is based on typical pAVM morphologies and a generic vessel network that represents realistic vascular feeding and draining components related to lesions. A lumped-parameter description of the vessel network was employed to compute blood pressure and flow rates. CA-transport was determined by coupling the model to a 1D advection-diffusion equation. Results show that the extent of hemodynamic effects of pAVMs, such as arterial steal and venous hypertension, strongly depends on the lesion type and its vascular architecture. Dimensions of shunting vessels strongly influence hemodynamic parameters. Our results underline the importance of the dynamics of CA-transport in diagnostic DSA images. In this context, we identified a set of temporal CA-transport parameters, which are indicative of the presence and specific morphology of pAVMs.

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Section: Patient-specific Vascular Network Modelmentioning

confidence: 99%

Section: Data Analysis and Diagnostic Parametersmentioning

confidence: 99%

Section: Data Analysis and Diagnostic Parametersmentioning

confidence: 99%

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Hemodynamic Characterization of Peripheral Arterio-venous Malformations

et al. 2017

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“…Scholars have established many in vitro models and conducted animal experiments to investigate the mixing of contrast agent and blood in vivo to improve X-ray photography quality 6 – 8 . Numerical simulations have also been adopted here 9 .…”

Section: Introductionmentioning

confidence: 99%

“…In silico experiments can offer doctors invaluable data that can hardly be obtained through in vivo operations. Researchers have carried out relevant investigations on intravascular injection relying on numerical simulation, such as contrast agent injection 9 , 22 , normal saline injection 23 – 25 and intravascular administration 26 . However, the existing numerical efforts focus only on modelling fluid flow and mixing, which is just one part of the OCT operation.…”

Section: Introductionmentioning

confidence: 99%

In silico intravascular optical coherence tomography (IVOCT) for quality assured imaging with reduced intervention

Zhuo,

Huang,

Xiao

2024

Sci Rep

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In the clinical application of intravascular optical coherence tomography (IVOCT), it is necessary to flush opaque blood during image acquisition. However, there are no specific standards for how to perform low-dose but effective flushing. In this study, computational fluid dynamics (CFD) and optical models were integrated to numerically simulate the complete process of IVOCT, which includes blood flushing with normal saline followed by image acquisition. Moreover, an intermittent injection scheme was proposed, and its advantages over the conventionally adopted scheme of continuous injection were verified. The results show that intermittent injection can significantly reduce the dosage of normal saline (reduced by 44.4%) with only a slight sacrifice of image quality (reduced by 8.7%, but still acceptable). The developed model and key findings in this work can help surgeons practice optimized IVOCT operations and potentially lead to improved designs of the IVOCT equipment.

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Pressure and Flow Rate Changes During Contrast Injections in Cerebral Angiography: Correlation to Reflux Length

Kovarovic

Woo

Fiorella

et al. 2018

Cardiovasc Eng Tech

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Cerebral angiography involves the antegrade injection of contrast media through a catheter into the vasculature to visualize the region of interest under X-ray imaging. Depending on the injection and blood flow parameters, the bolus of contrast can propagate in the upstream direction and proximal to the catheter tip, at which point contrast is said to have refluxed. In this in vitro study, we investigate the relationship of fundamental hemodynamic variables to this phenomenon. Contrast injections were carried out under steady and pulsatile flow using various vessel diameters, catheter sizes, working fluid flow rates, and injection rates. The distance from the catheter tip to the proximal edge of the contrast bolus, called reflux length, was measured on the angiograms; the relation of this reflux length to different hemodynamic parameters was evaluated. Results show that contrast reflux occurs when the pressure distal to the catheter tip increases to be greater than the pressure proximal to the catheter tip. The ratio of this pressure difference to the baseline flow rate, called reflux resistance here, was linearly correlated to the normalized reflux length (reflux length/vessel diameter). Further, the ratio of blood flow to contrast fluid momentums, called the Craya-Curtet number, was correlated to the normalized reflux length via a sigmoid function. A sigmoid function was also found to be representative of the relationship between the ratio of the Reynolds numbers of blood flow to contrast and the normalized reflux length. As described by previous reports, catheter based contrast injections cause substantial increases in local flow and pressure. Contrast reflux should generally be avoided during standard antegrade angiography. Our study shows two specific correlations between contrast reflux length and baseline and intra-injection parameters that have not been published previously. Further studies need to be conducted to fully characterize the phenomena and to extract reliable indicators of clinical utility. Parameters relevant to cerebral angiography are studied here, but the essential principles are applicable to all angiographic procedures involving antegrade catheter injections.

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Dispersive Transport of Angiographic Contrast During Antegrade Arterial Injection

Cited by 3 publications

References 14 publications

Hemodynamic Characterization of Peripheral Arterio-venous Malformations

Hemodynamic Characterization of Peripheral Arterio-venous Malformations

In silico intravascular optical coherence tomography (IVOCT) for quality assured imaging with reduced intervention

Pressure and Flow Rate Changes During Contrast Injections in Cerebral Angiography: Correlation to Reflux Length

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