scholarly journals In vivo Assessment of Human Brainstem Cerebrovascular Function: A Multi-Inversion Time Pulsed Arterial Spin Labelling Study

2014 ◽  
Vol 34 (6) ◽  
pp. 956-963 ◽  
Author(s):  
Esther AH Warnert ◽  
Ashley D Harris ◽  
Kevin Murphy ◽  
Neeraj Saxena ◽  
Neeta Tailor ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Vascular Reactivity ◽  
Kinetic Curve ◽  
Tissue Perfusion ◽  
Compartment Model ◽  
Arterial Spin Labelling ◽  
Inversion Time ◽  
Cerebrovascular Function ◽  
Spin Labelling

The brainstem (BS) is involved in critical physiologic processes, including control of cardiovascular and respiratory functions. This study implements a multi-inversion time pulsed arterial spin labelling (MTI PASL) imaging sequence that addresses the challenges of BS imaging and aims to measure normal and elevated BS perfusion in healthy volunteers. An initial experiment was performed to obtain the kinetic curve of the label in the BS and consequently to estimate the label arrival times and tissue perfusion in seven participants. A second experiment estimated the BS cerebral vascular reactivity (CVR) to hypercapnia in 10 participants. Images were acquired with a gradient-echo sequence with two spiral interleaves and short echo time (TE = 2.7 ms). Data were analyzed with a two-compartment model, including a tissue and arterial component. In both experiments, perfusion in the BS was significantly lower than in cortical gray matter (repeated measures analysis of variance (RM-ANOVA), P<0.05), which is as expected since the BS consists of gray and white matter, the latter typically showing lower perfusion. The BS CVR found here is comparable to previous reports obtained with positron emission tomography (PET) imaging. Multi-inversion time pulsed ASL in combination with a two-compartment signal model can be used to assess BS perfusion and CVR.

scholarly journals Assessment of the effects of aerobic fitness on cerebrovascular function in young adults using multiple inversion time arterial spin labelling MRI

2019 ◽  
Author(s):  
Catherine Foster ◽  
Jessica J Steventon ◽  
Daniel Helme ◽  
Valentina Tomassini ◽  
Richard G. Wise
Keyword(s):  
Young Adults ◽  
Aerobic Fitness ◽  
Arterial Spin Labelling ◽  
Cerebrovascular Reactivity ◽  
Inverse Association ◽  
Cross Sectional ◽  
Whole Brain ◽  
Inversion Time ◽  
Cerebrovascular Function ◽  
Spin Labelling

AbstractThe cross-sectional study investigated the effects of aerobic fitness on cerebrovascular function in the healthy brain. We quantified grey matter (GM) cerebral blood flow (CBF) and cerebrovascular reactivity (CVR), in a sample of young adults within a normal fitness range. Based on existing TCD and fMRI evidence, we predicted a positive relationship between fitness and resting GM CBF, and CVR. Exploratory hypotheses that higher peak would be associated with higher GM volume and cognitive performance were also investigated.20 adults underwent a peak test and a battery of cognitive tests. All subjects underwent an MRI scan where multiple inversion time (MTI) pulsed arterial spin labelling (PASL) was used to quantify resting CBF and CVR to 5% CO2.ROI analysis showed a non-significant negative correlation between whole-brain GM CBF and peak; r=-0.4, p=0.08, corrected p (p’) =0.16 and a significant positive correlation between peak and voxelwise whole-brain GM CVR; r=0.62, p=0.003, p’ =0.006. Voxelwise analysis revealed a significant inverse association between peak and resting CBF in the left and right thalamus, brainstem, right lateral occipital cortex, left intracalcarine cortex and cerebellum. The results of this study suggest that aerobic fitness is associated with lower CBF and greater CVR in young adults.

scholarly journals Effects of red blood cells with reduced deformability on cerebral blood flow and vascular water transport: measurements in rats using time-resolved pulsed arterial spin labelling at 9.4 T

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Adnan Bibic ◽  
Tea Sordia ◽  
Erik Henningsson ◽  
Linda Knutsson ◽  
Freddy Ståhlberg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Repeated Measures ◽  
Arterial Spin Labelling ◽  
Control Group ◽  
Study Group ◽  
Percentage Points ◽  
Spin Labelling

Abstract Background Our aim was to introduce damaged red blood cells (RBCs) as a tool for haemodynamic provocation in rats, hypothesised to cause decreased cerebral blood flow (CBF) and prolonged water capillary transfer time (CTT), and to investigate whether expected changes in CBF could be observed and if haemodynamic alterations were reflected by the CTT metric. Methods Damaged RBCs exhibiting a mildly reduced deformability were injected to cause aggregation of RBCs. Arterial spin labelling (ASL) magnetic resonance imaging experiments were performed at 9.4 T. Six datasets (baseline plus five datasets after injection) were acquired for each animal in a study group and a control group (13 and 10 female adult Wistar rats, respectively). For each dataset, ASL images at ten different inversion times were acquired. The CTT model was adapted to the use of a measured arterial input function, implying the use of a realistic labelling profile. Repeated measures ANOVA was used (alpha error = 0.05). Results After injection, significant differences between the study group and control group were observed for relative CBF in white matter (up to 20 percentage points) and putamen (up to 18–20 percentage points) and for relative CTT in putamen (up to 35–40 percentage points). Conclusions Haemodynamic changes caused by injection of damaged RBCs were observed by ASL-based CBF and CTT measurements. Damaged RBCs can be used as a tool for test and validation of perfusion imaging modalities. CTT model fitting was challenging to stabilise at experimental signal-to-noise ratio levels, and the number of free parameters was minimised.

P3-422: PROTOCOL HARMONISATION AND IN-VIVO COMPARISON OF ARTERIAL SPIN LABELLING PERFUSION MRI FOR MULTICENTER CLINICAL TRIALS

2006 ◽  
Vol 14 (7S_Part_24) ◽  
pp. P1269-P1271
Author(s):  
Maryam Abaei ◽  
Koen P.A. Baas ◽  
Jan Petr ◽  
Derek L. Hill ◽  
Robin Wolz ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Arterial Spin Labelling ◽  
Perfusion Mri ◽  
Multicenter Clinical Trials ◽  
Spin Labelling

scholarly journals Designing and Comparing Optimised Pseudo-Continuous Arterial Spin Labelling Protocols for Measurement of Cerebral Blood Flow

2020 ◽  
Author(s):  
Joseph G. Woods ◽  
Michael A. Chappell ◽  
Thomas W. Okell
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arterial Spin Labelling ◽  
In Vivo Experiments ◽  
Wide Range ◽  
Arterial Transit Time ◽  
Hybrid Protocols ◽  
Accuracy And Repeatability ◽  
Spin Labelling

1.AbstractArterial Spin Labelling (ASL) is a non-invasive, non-contrast, perfusion imaging technique which is inherently SNR limited. It is, therefore, important to carefully design scan protocols to ensure accurate measurements. Many pseudo-continuous ASL (PCASL) protocol designs have been proposed for measuring cerebral blood flow (CBF), but it has not yet been demonstrated which design offers the most accurate and repeatable CBF measurements. In this work, a wide range of literature PCASL protocols, including single-delay, sequential and time-encoded multi-timepoint protocols, and several novel protocol designs, which are hybrids of time-encoded and sequential multi-timepoint protocols, were first optimised using a Cramér-Rao Lower Bound framework and then compared for CBF accuracy and repeatability using Monte Carlo simulations and in vivo experiments. It was found that several multi-timepoint protocols produced more confident, accurate, and repeatable CBF estimates than the single-delay protocol, while also generating maps of arterial transit time. One of the novel hybrid protocols, HybridT1-adj, was found to produce the most confident, accurate and repeatable CBF estimates of all protocols tested in both simulations and in vivo (24%, 47%, and 28% more confident, accurate, and repeatable than single-PLD in vivo). The HybridT1-adj protocol makes use of the best aspects of both time-encoded and sequential multi-timepoint protocols and should be a useful tool for accurately and efficiently measuring CBF.

Separation of macrovascular signal in multi-inversion time arterial spin labelling MRI

2010 ◽  
Vol 63 (5) ◽  
pp. 1357-1365 ◽  
Author(s):  
Michael A. Chappell ◽  
Bradley J. MacIntosh ◽  
Manus J. Donahue ◽  
Matthias Günther ◽  
Peter Jezzard ◽  
...  
Keyword(s):  
Arterial Spin Labelling ◽  
Inversion Time ◽  
Spin Labelling

CARDIAC ARTERIAL SPIN LABELLING MRI AS A NOVEL APPROACH FOR IN VIVO QUANTIFICATION OF THE AREA-AT-RISK

Heart ◽  
2014 ◽  
Vol 100 (Suppl 4) ◽  
pp. A18.3-A19
Author(s):  
RK Dongworth ◽  
AE Campbell-Washburn ◽  
T Roberts ◽  
DM Yellon ◽  
MF Lythgoe ◽  
...  
Keyword(s):  
At Risk ◽  
Arterial Spin Labelling ◽  
Area At Risk ◽  
Novel Approach ◽  
Spin Labelling
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