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.

scholarly journals Regional cerebral blood flow in late-life depression: arterial spin labelling magnetic resonance study

2012 ◽  
Vol 200 (2) ◽  
pp. 150-155 ◽  
Author(s):  
Sean J. Colloby ◽  
Michael J. Firbank ◽  
Jiabao He ◽  
Alan J. Thomas ◽  
Akshya Vasudev ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Magnetic Resonance ◽  
Rating Scale ◽  
Late Life ◽  
Arterial Spin Labelling ◽  
Control Group ◽  
Late Life Depression ◽  
Spin Labelling

BackgroundA limited number of studies have demonstrated changes in cerebral blood flow (CBF) in older individuals with depression, but there are considerable inconsistencies between studies.AimsTo investigate changes in CBF using arterial spin labelling (ASL) magnetic resonance imaging (MRI) in people with late-life depression and in a similarly aged healthy control group.MethodSixty-eight participants (30 healthy individuals, 38 with depression) underwent ASL and T1-weighted MRI scanning. For each individual, regional estimates of separate grey and white matter CBF were obtained. Group differences in CBF and their associations with clinical features were examined.ResultsSignificant increases were observed in white matter CBF in patients with depression relative to the control group (F1,65 = 9.7, P = 0.003). Grey matter CBF in lateral frontal, medial frontal, cingulate, central and parietal regions did not significantly differ between groups (F1,65≤2.1, P≥0.2). A significant correlation was found between white matter CBF and Montgomery–Åsberg Depression Rating Scale (MADRS) scores in depression (r’ =–0.42, P = 0.03). Further analyses revealed that compared with controls, significant elevation of white matter CBF was apparent in participants whose depression was in remission (n = 21, MADRS≤10, P = 0.001) but not in those with current depression (n = 17, MADRS≥11, P = 0.80).ConclusionsFindings suggest a compensatory response to white matter pathological change or a response to (or a predictor of) successful antidepressant treatment, perhaps by facilitating neurotransmission in specific circuits and so reducing depressive symptoms.

scholarly journals Cerebral perfusion changes in presymptomatic genetic frontotemporal dementia: a GENFI study

Brain ◽  
2019 ◽  
Vol 142 (4) ◽  
pp. 1108-1120 ◽  
Author(s):  
Henri J M M Mutsaerts ◽  
Saira S Mirza ◽  
Jan Petr ◽  
David L Thomas ◽  
David M Cash ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Frontotemporal Dementia ◽  
Symptom Onset ◽  
Arterial Spin Labelling ◽  
Anterior Cingulate ◽  
Middle Temporal Gyrus ◽  
Inverse Association ◽  
Mutation Carriers ◽  
Spin Labelling

Abstract Genetic forms of frontotemporal dementia are most commonly due to mutations in three genes, C9orf72, GRN or MAPT, with presymptomatic carriers from families representing those at risk. While cerebral blood flow shows differences between frontotemporal dementia and other forms of dementia, there is limited evidence of its utility in presymptomatic stages of frontotemporal dementia. This study aimed to delineate the cerebral blood flow signature of presymptomatic, genetic frontotemporal dementia using a voxel-based approach. In the multicentre GENetic Frontotemporal dementia Initiative (GENFI) study, we investigated cross-sectional differences in arterial spin labelling MRI-based cerebral blood flow between presymptomatic C9orf72, GRN or MAPT mutation carriers (n = 107) and non-carriers (n = 113), using general linear mixed-effects models and voxel-based analyses. Cerebral blood flow within regions of interest derived from this model was then explored to identify differences between individual gene carrier groups and to estimate a timeframe for the expression of these differences. The voxel-based analysis revealed a significant inverse association between cerebral blood flow and the expected age of symptom onset in carriers, but not non-carriers. Regions included the bilateral insulae/orbitofrontal cortices, anterior cingulate/paracingulate gyri, and inferior parietal cortices, as well as the left middle temporal gyrus. For all bilateral regions, associations were greater on the right side. After correction for partial volume effects in a region of interest analysis, the results were found to be largely driven by the C9orf72 genetic subgroup. These cerebral blood flow differences first appeared approximately 12.5 years before the expected symptom onset determined on an individual basis. Cerebral blood flow was lower in presymptomatic mutation carriers closer to and beyond their expected age of symptom onset in key frontotemporal dementia signature regions. These results suggest that arterial spin labelling MRI may be a promising non-invasive imaging biomarker for the presymptomatic stages of genetic frontotemporal dementia.

scholarly journals Measuring the Effects of Remifentanil on Cerebral Blood Flow and Arterial Arrival Time Using 3D Grase MRI with Pulsed Arterial Spin Labelling

2008 ◽  
Vol 28 (8) ◽  
pp. 1514-1522 ◽  
Author(s):  
Bradley J Macintosh ◽  
Kyle TS Pattinson ◽  
Daniel Gallichan ◽  
Imran Ahmad ◽  
Karla L Miller ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arrival Time ◽  
Spin Echo ◽  
Three Dimensional ◽  
Brain Perfusion ◽  
Arterial Spin Labelling ◽  
Permutation Testing ◽  
Significant Difference ◽  
Spin Labelling

Arterial spin labelling (ASL) has proved to be a promising magnetic resonance imaging (MRI) technique to measure brain perfusion. In this study, volumetric three-dimensional (3D) gradient and spin echo (GRASE) ASL was used to produce cerebral blood flow (CBF) and arterial arrival time (AAT) maps during rest and during an infusion of remifentanil. Gradient and spin echo ASL perfusion-weighted images were collected at multiple inflow times (500 to 2,500 ms in increments of 250 ms) to accurately fit an ASL perfusion model. Fit estimates were assessed using z-statistics, allowing voxels with a poor fit to be excluded from subsequent analyses. Nonparametric permutation testing showed voxels with a significant difference in CBF and AAT between conditions across a group of healthy participants ( N = 10). Administration of remifentanil produced an increase in end-tidal CO2, an increase in CBF from 57 ± 12.0 to 77 ± 18.4 mL/100 g tissue per min and a reduction in AAT from 0.73 ± 0.073 to 0.64 ± 0.076 secs. Within grey matter, remifentanil produced a cerebrovascular response of 5.7 ± 1.60 %CBF per mm Hg. Significant differences between physiologic conditions were observed in both CBF and AAT maps, indicating that 3D GRASE-ASL has the sensitivity to study changes in physiology at a voxel level.

scholarly journals Robust estimation of the cerebral blood flow in arterial spin labelling

2014 ◽  
Vol 32 (5) ◽  
pp. 497-504 ◽  
Author(s):  
Camille Maumet ◽  
Pierre Maurel ◽  
Jean-Christophe Ferré ◽  
Christian Barillot
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Robust Estimation ◽  
Arterial Spin Labelling ◽  
Spin Labelling
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