Transcranial Doppler and Transcranial Color Duplex in Defining Collateral Cerebral Blood Flow

Saqqur, Maher; Khan, Khurshid; Derksen, Carol; Alexandrov, Andrei V.; Shuaib, Ashfaq

doi:10.1111/jon.12535

Cited by 23 publications

(20 citation statements)

References 134 publications

(301 reference statements)

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“…While the velocity contours intuitively show the abrupt changes in the velocities of the ipsilateral cerebral arteries, the iso-volumetric contours illustrated the representative changes in the visibility of the arteries. The correlation of the absent functionality of A1 to severe CS has been demonstrated by Hoksbergen et al (2003), but our results showed that A1 became functional again with the redirected flow from the contralateral hemisphere at 95% severity, which is coherent with the findings made using US data (Saqqur et al, 2018). The PCoAs also became functional at the ipsilateral side in response to ipsilateral CS progression while the contralateral side remained inactive (Figure 7A).…”

Section: Transitional Stages Of Cow During Cs Progressionsupporting

confidence: 89%

Effects of progressive carotid stenosis on cerebral haemodynamics: aortic-cerebral 3D patient-specific simulation

Kang

Mukherjee

Kim

et al. 2021

Engineering Applications of Computational Fluid Mechanics

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We investigated the effects of atherosclerosis in the carotid region on cerebral haemodynamics. A total of 15 stenosis cases following NASCET criteria were modelled using patient-specific medical image data and an open-source package, SimVascular. The formulation adopted the stabilised Petrov-Galerkin scheme with Newtonian and incompressible assumptions. The boundary conditions employed pulsatile inflow and three-element lumped Windkessel outlet conditions with a rigid wall assumption. We present transitions in the represented CoW during stenosis progression using three-dimensional aortic-cerebral vasculature for the first time. This was driven by the conserved total cerebral blood flow to 50% carotid stenosis (CS) (P-value, P > 0.05), which deteriorated during subsequent stages of CS (P < 0.01), and the effective collateral capability of the communicating arteries (CoAs) activated from a degree of 75% and above (P < 0.0001). The prevalence of 'complete' CoW peaked at 50% CS and then declined. Despite the collateral flow, the ipsilateral hemispheric perfusion was moderately reduced (P < 0.01), and the contralateral perfusion was conserved (P > 0.05), revealing the ineffectiveness of collateral capability of CoW at the extreme stages of CS. We identified bulk cerebral auto-regulation effects of the conventional Windkessel model, demonstrating accurate flow reduction in the stenosed artery.

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Section: Transitional Stages Of Cow During Cs Progressionsupporting

confidence: 89%

Effects of progressive carotid stenosis on cerebral haemodynamics: aortic-cerebral 3D patient-specific simulation

Kang

Mukherjee

Kim

et al. 2021

Engineering Applications of Computational Fluid Mechanics

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“…Color Doppler ultrasound is an ultrasound diagnostic technology that uses color images to display the direction and relative velocity of blood flow in real time on the basis of two-dimensional gray-scale ultrasound images. It is the most accurate and most widely used ultrasound examination method, and its judgment and sensitivity of the nature of the disease is much higher than that of ordinary examination [ 19 ]. However, due to imaging equipment and other reasons, unnecessary interference information such as noise often appears in color Doppler ultrasound images, which affects the image quality and makes the readers unable to make accurate judgments of the disease, causing troubles in clinical work.…”

Section: Discussionmentioning

confidence: 99%

Doppler Ultrasound under Image Denoising Algorithm in the Diagnosis and Treatment of Fetal Growth Restriction Using Aspirin Combined with Low-Molecular-Weight Heparin

Liu

Niu

Zeng

2021

Journal of Healthcare Engineering

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Objective. This study explored the clinical application value of image denoising algorithm combined with Doppler ultrasound imaging in evaluation of aspirin combined with low-molecular-weight heparin (LMWH) on fetal growth restriction (FGR). Method. A two-stage image denoising by principal component analysis (PCA) with local pixel grouping (LPG-PCA) denoising algorithm was constructed in this study. Eighty FGR pregnant women were included in the study, and they were rolled into an experimental group (aspirin enteric-coated tablets + LMWH calcium injection) and a control group (LMWH calcium injection) according to the different treatment plans, with 40 cases in each group. All patients were performed with Doppler ultrasound imaging. The blood flow parameters (BFPs) were recorded and compared before and after the treatment in two groups, including power index (PI), resistance index (RI), high systolic blood flow velocity (S), high diastolic blood flow velocity (D), S/D value, and peak systolic velocity (PSV). In addition, the middle cerebral artery (MCA) BFPs, cerebral placental rate (CPR), amniotic fluid index (AFI) and perinatal outcome (PO) of the two groups were compared. Results. The total effective rate of treatment in group A (87.5%) was greatly higher than that in group B (62.5%), showing statistical difference (P < 0.05). The PI (0.72 ± 0.19), RI (0.57 ± 0.17), and S/D values (2.26 ± 0.43) in group A were dramatically lower than those in group B, which were 0.92 ± 0.21, 0.75 ± 0.14, and 2.64 ± 0.45, respectively (P < 0.05), and the AFI was higher (13.71 ± 2.2 cm vs 11.38 ± 2.16 cm) (P < 0.05). The Apgar score (9.17 ± 0.26), weight (3.57 ± 1.08), and gestational age (38.85 ± 2.50) of group A were all higher in contrast to those of group B, which were 7.33 ± 0.25, 2.61 ± 1.13, and 36.18 ± 2.25, respectively (P < 0.05). In addition, the fetal double parietal diameter (2.4 ± 0.9 mm), femur diameter (2.2 ± 0.6 mm), head circumference (1.2 ± 0.4 mm), abdominal circumference (1.3 ± 0.7 mm), and uterine height (0.8 ± 0.3 mm) in group A were obviously superior to those in group B, which were 1.8 ± 0.4 mm, 1.7 ± 0.5 mm, 0.8 ± 0.2 mm, 0.9 ± 0.4 mm, and 0.4 ± 0.6 mm, respectively, showing statistically observable differences (P < 0.05). Conclusion. Doppler ultrasound based on image denoising algorithm can accurately evaluate the effect of aspirin combined with LMWH on the improvement of FGR and showed good application value.

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“…Cerebral blood flow can be measured by transcranial doppler ultrasound. A pseudovenous flow pattern or impaired flow-reserve in the breath holding (or CO 2 inhalation) test indicating a maximal activated autoreserve in the MCA might serve as prognostic tool, yet has not been widely studied in this setting (84)(85)(86). Computed tomography or magnet resonance imaging perfusion imaging is well established to visualize the penumbra in ischemic stroke and has been successfully applied in randomized controlled thrombectomy trials (87,88), yet a clear imaging definition of low-flow situations has yet to be established.…”

Section: Discussionmentioning

confidence: 99%

Management and prognosis of acute extracranial internal carotid artery occlusion

Mayer¹,

Grams²,

Freyschlag³

et al. 2020

Ann Transl Med

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Acute occlusion of the internal carotid artery is the underlying etiology in 4 to 15% of all ischemic strokes. The clinical presentation varies considerably ranging from asymptomatic occlusion to severe ischemic strokes. Substantial differences in the acute management of acute symptomatic internal carotid artery occlusions (ICAO) exists between centers. Thusly, we comprised a narrative review of the natural course of acute ICAO and of available treatment options [i.v. thrombolysis, endovascular thrombectomy and stenting, bypass between the superficial temporal and the middle cerebral arteries (MCA) and carotid endarterectomy (CEA)]. We found that very few randomized treatment trials have been performed in patients acute symptomatic ICAO. Most evidence stems from case series and observational studies. Especially in older studies the intracranial vessel status has rarely been considered. After revision of these studies we concluded that the mainstay of the acute management of acute symptomatic ICAO is i.v. thrombolysis when applied within the label and in combination with mechanical thrombectomy in case of intracranial large vessel occlusion. In cases without intracranial large vessel occlusion mechanical thrombectomy of acute ICAO is associated with a risk of distal embolization. More research on prognostic parameters is needed to better characterize the risk of decompensation of collateral flow and to better define the time-window of intervention. When mechanical thrombectomy fails or is not available, surgical approaches are an alternative in selected patients.

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Transcranial Doppler and Transcranial Color Duplex in Defining Collateral Cerebral Blood Flow

Cited by 23 publications

References 134 publications

Effects of progressive carotid stenosis on cerebral haemodynamics: aortic-cerebral 3D patient-specific simulation

Effects of progressive carotid stenosis on cerebral haemodynamics: aortic-cerebral 3D patient-specific simulation

Doppler Ultrasound under Image Denoising Algorithm in the Diagnosis and Treatment of Fetal Growth Restriction Using Aspirin Combined with Low-Molecular-Weight Heparin

Management and prognosis of acute extracranial internal carotid artery occlusion

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