Analysis of Intra-Aneurysmal Flow for Cerebral Aneurysms with Cerebral Angiography

Jou, Liang Der; Mawad, Michel E.

doi:10.3174/ajnr.a3057

Cited by 16 publications

(26 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A previous study shows that the contrast concentration is the highest at the diastole when the arterial flow rate is the lowest (14). At higher injection rates, the systolic flow with a low contrast concentration enters the aneurysm that has been enhanced by the contrast agent from previous periods so the systolic flow jet is hardly noticeable; on the other hand, the diastolic flow carrying a higher contrast concentration is easier to identify on subtracted images.…”

Section: Discussionmentioning

confidence: 99%

“…Our results also demonstrate the possibility of visualizing systolic and diastolic flow patterns by controlling the contrast injection rate. Based on our findings, the high injection rates used previously in other studies (1.5-2 mL/s) explored only the diastolic flow for the ICA aneurysms (11,14). The systolic flow jet that contributes to elevation of wall shear stress (19) and is responsible for flow impingement has been ignored in the DSA.…”

Section: Discussionmentioning

confidence: 99%

“…The timing of intra-aneurysmal flow jet into the aneurysm was identified on the subtracted images and the frame associated with a surge of the contrast at the aneurysm was recorded. At each run, more than one contrast jet could be observed on the subtracted images (11,14), and the second jet was used for analysis because the first jet was often truncated and incomplete. These frames marked the instant of contrast bolus arrival and the specific time of a cycle when flow impingement occurred.…”

Section: Methodsmentioning

confidence: 99%

“…The hyper-intense signal on the DSA is associated with the diastole flow during which the contrast agent is less diluted by blood (14). The contrast agent is diluted considerably during the systole and produces a lower signal.…”

Section: Introductionmentioning

confidence: 99%

“…Several other variables, such as diffusion and convection relaxation times, have also been used for quantification of flow diversion (12). These DSA-based techniques provide a convenient way to assess the effect of flow diversion during an endovascular procedure, and most of them require a bolus of contrast injection (13), with an extended period of imaging (12) and/or at higher DSA frame rate (11,13,14).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

In vitro investigation of contrast flow jet timing in patient-specific intracranial aneurysms

Jou

Desai

Britz

2016

Quant. Imaging Med. Surg.

View full text Add to dashboard Cite

Background: The direction and magnitude of intra-aneurysmal flow jet are significant risk factors of subarachnoid hemorrhage, and the change of flow jet during an endovascular procedure has been used for prediction of aneurysm occlusion or whether an additional flow diverter (FD) is warranted. However, evaluation of flow jets is often unreliable due to a large variation of flow jet on the digital subtraction angiograms, and this flow pattern variation may result in incorrect clinical diagnosis Therefore, factors contributing to the variation in flow jet are examined at an in vitro setting, and the findings can help us to understand the nature of flow jet and devise a better plan to quantify the aneurysmal hemodynamics accurately.Methods: Intra-aneurysmal flows in three patient-specific aneurysms between 11 and 25 mm were investigated in vitro, and a FD was deployed in each aneurysm model. X-ray imaging of these models were performed at injection rates between 0.2 and 2 mL/s. Pulsatile blood pump and aneurysm model were imaged together to determine the timing of flow jet. Results:The contrast bolus arrives at the aneurysm early at high contrast injection rates. The flow patterns with slow injection rates exhibit strong inertia that is associated with the systole flow. Flow jets arrive at the aneurysms at the peak systole when the bolus is injected at 0.2 mL/s. The contrast-to-signal ratio is the highest at the injection rate of 0.5 mL/s. Effect of flow diversion can only be assessed at an injection rate greater than 0.5 mL/s.Conclusions: Intra-aneurysmal flow jet is highly dependent on the injection rate of the contrast agent.For the internal carotid artery (ICA) aneurysms, the systolic flows can be visualized at slow injection rates (<0.5 mL/s), while the diastolic flow jets are visible at higher injection rates (>1 mL/s). Dependence of flow jet on the contrast injection rate has serious clinical implications and needs to be considered during diagnostic procedures; a protocol with a consistent injection rate is highly recommended.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

In vitro investigation of contrast flow jet timing in patient-specific intracranial aneurysms

Jou

Desai

Britz

2016

Quant. Imaging Med. Surg.

View full text Add to dashboard Cite

show abstract

Digital Subtraction Angiography (DSA): Basic Principles

Castillo

2013

Vascular Imaging of the Central Nervous System

View full text Add to dashboard Cite

From2Dto4DPhase‐ContrastMRIin the Neurovascular System: Will It Be a Quantum Jump or a Fancy Decoration?

Youn

Lee

2020

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Considering the crosstalk between the flow and vessel wall, hemodynamic assessment of the neurovascular system may offer a well-integrated solution for both diagnosis and management by adding prognostic significance to the standard CT/MR angiography. 4D flow MRI or time-resolved 3D velocity-encoded phase-contrast MRI has long been promising for the hemodynamic evaluation of the great vessels, but challenged in clinical studies for assessing intracranial vessels with small diameter due to long scan times and low spatiotemporal resolution. Current accelerated MRI techniques, including parallel imaging with compressed sensing and radial k-space undersampling acquisitions, have decreased scan times dramatically while preserving spatial resolution. 4D flow MRI visualized and measured 3D complex flow of neurovascular diseases such as aneurysm, arteriovenous shunts, and atherosclerotic stenosis using parameters including flow volume, velocity vector, pressure gradients, and wall shear stress. In addition to the noninvasiveness of the phase contrast technique and retrospective flow measurement through the wanted windows of the analysis plane, 4D flow MRI has shown several advantages over Doppler ultrasound or computational fluid dynamics. The evaluation of the flow status and vessel wall can be performed simultaneously in the same imaging modality. This article is an overview of the recent advances in neurovascular 4D flow MRI techniques and their potential clinical applications in neurovascular disease. Level of Evidence: 5 Technical Efficacy Stage: 3

show abstract

Analysis of Intra-Aneurysmal Flow for Cerebral Aneurysms with Cerebral Angiography

Cited by 16 publications

References 19 publications

In vitro investigation of contrast flow jet timing in patient-specific intracranial aneurysms

In vitro investigation of contrast flow jet timing in patient-specific intracranial aneurysms

Digital Subtraction Angiography (DSA): Basic Principles

From2Dto4DPhase‐ContrastMRIin the Neurovascular System: Will It Be a Quantum Jump or a Fancy Decoration?

Contact Info

Product

Resources

About