Measurement of Blood Flow in Arteriovenous Malformations before and after Embolization Using Arterial Spin Labeling

The assessment of shunt reduction after an embolization of an arteriovenous malformation (AVM) or fistula (AVF) from conventional angiography is often difficult and may be subjective. Here we present a completely non-invasive method using magnetic resonance imaging (MRI) to measure shunt reduction. Using pulsed arterial spin labeling (PASL), we determined the relative amount of signal attributed to the shunt over 1.75 s and 6 different slices covering the lesion. This amount of signal from the shunt was related to the total signal from all slices and measured before and after embolization. The method showed a fair agreement between the PASL results and the judgement from conventional angiography. In the case of a total or subtotal shunt occlusion, PASL showed a shunt reduction between 69% and 92%, whereas in minimal shunt reduction as judged by conventional angiography, the ASL result was −6% (indicating slightly increased flow) to 35% in a partially occluded vein of Galen aneurysm. The PASL method proved to be fairly reproducible (up to 2% deviation between three measurements without interventions). On conclusion, PASL is able to reliably measure the amount of shunt reduction achieved by embolization of AVMs and AVFs.

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The Potential Utility of Arterial Spin Labeling in Detecting and Localizing Posterior Circulation Occlusions in Every Day Practice: A Clinical Report of Selected Cases

Journal of Clinical Imaging Science ◽

10.25259/jcis_118_2020 ◽

2020 ◽

Vol 10 ◽

pp. 78

Author(s):

Vivek Yedavalli ◽

Elizabeth Tong

Keyword(s):

Arterial Spin Labeling ◽

Cerebral Perfusion ◽

Spin Labeling ◽

Posterior Circulation ◽

Clinical Report ◽

Stroke Subtype ◽

Everyday Clinical Practice ◽

Anterior Circulation ◽

Non Invasive ◽

Invasive Method

Arterial spin labeling (ASL) is a non-contrast, non-invasive method used for the evaluation of cerebral perfusion, which is now increasingly utilized in everyday clinical practice. As a marker of cerebral blood flow at the capillary level, it has particular utility in stroke assessment. One rarer stroke subtype with non-specific symptomatology that can lead to significant morbidity is the posterior circulation (PC) infarct. As with the more common anterior circulation infarcts, ASL has shown benefit in PC infarcts as well, but has not been extensively explored in the literature nor been directly compared to bolus perfusion techniques. This clinical report of selected cases shows the utility of ASL in localization and detection of PC infarcts both in conjunction with and in the absence of bolus perfusion.

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Introduction to Perfusion Quantification using Arterial Spin Labelling

10.1093/oso/9780198793816.001.0001 ◽

2017 ◽

Cited By ~ 3

Author(s):

Michael Chappell ◽

Bradley MacIntosh ◽

Thomas Okell

Keyword(s):

Arterial Spin Labeling ◽

Real Data ◽

Pharmacological Intervention ◽

Non Invasive ◽

Analysis Process ◽

Invasive Method ◽

The Common ◽

Perfusion Quantification ◽

Magnetic Resonance Imaging Mri ◽

The Brain

Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is unique in being a completely non-invasive method for imaging perfusion in the brain. Relying upon a blood-borne tracer that is created by the MRI scanner itself, ASL is becoming a popular tool to study cerebral perfusion, as well as how this perfusion changes in response to neuronal activity or in disease. This primer provides an introduction to perfusion quantification using ASL MRI, focusing both on the methods needed to extract perfusion-weighted images and on how to quantify perfusion and other hemodynamic parameters. Starting with the simplest implementation of ASL, the primer details all the common acquisition methods, as well as the subsequent analysis steps required to quantify perfusion in an individual, detect changes in perfusion in response to neural activity or pharmacological intervention, and examine perfusion variations across groups of individuals. This is supported with examples from real data illustrating all the major steps in the analysis process, linked to online material where the reader can undertake the same analysis for themselves.

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Measurement of changes in perfusion after carotid endarterectomy by 3D pseudo-continuous arterial spin labeling

10.21203/rs.3.rs-19545/v1 ◽

2020 ◽

Author(s):

Dongsheng Kong ◽

Zhe Xue ◽

Chen Wu ◽

Wenxin Wang ◽

Zhenghui Sun ◽

...

Keyword(s):

Carotid Endarterectomy ◽

Carotid Stenosis ◽

Arterial Spin Labeling ◽

Spin Labeling ◽

Early Postoperative Period ◽

Postoperative Treatment ◽

Non Invasive ◽

Before And After ◽

Flow Changes ◽

Continuous Arterial Spin Labeling

Abstract Background:Carotid endarterectomy (CEA) is an effective method for treating cerebral ischemia caused by carotid stenosis, but there may be a risk of perfusion pressure breakthrough during early perfusion recovery. As a non-invasive and contrast-free magnetic resonance examination method, arterial spin labeling can be used for continuous observation and measurement in the early postoperative period of carotid endarterectomy. Results: Nineteen patients with severe unilateral carotid stenosis were examined using 3D pseudo-continuous arterial spin labeling before and after CEA, and we found that the pattern of dynamic cerebral blood flow changes is not the same in different regions.Conclusions: 3D pseudo-continuous arterial spin labeling might be helpful for the improvement of postoperative treatment and care of severe unilateral carotid stenosis patients.

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Non-invasive assessment of cerebral blood flow using selective MR-Arterial Spin Labeling (ASL): First Experience

Klinische Neurophysiologie ◽

10.1055/s-0030-1250925 ◽

2010 ◽

Vol 41 (01) ◽

Author(s):

R Wiest ◽

K Jann ◽

J Gralla ◽

M Hauf ◽

J Wang ◽

...

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Arterial Spin Labeling ◽

Spin Labeling ◽

Non Invasive

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CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

European Radiology ◽

10.1007/s00330-021-07692-5 ◽

2021 ◽

Author(s):

Patrick Veit-Haibach ◽

Martin W. Huellner ◽

Martin Banyai ◽

Sebastian Mafeld ◽

Johannes Heverhagen ◽

...

Keyword(s):

Peripheral Arterial Disease ◽

Ct Perfusion ◽

Arterial Disease ◽

Lower Leg ◽

Therapy Control ◽

Non Invasive ◽

Before And After ◽

Invasive Method ◽

The Mean ◽

Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

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