scholarly journals Diurnal Variations in Neural Activity of Healthy Human Brain Decoded with Resting-State Blood Oxygen Level Dependent fMRI

2016 ◽  
Vol 10 ◽  
Author(s):  
Chunxiang Jiang ◽  
Li Yi ◽  
Shi Su ◽  
Caiyun Shi ◽  
Xiaojing Long ◽  
...  
Keyword(s):  
Human Brain ◽  
Neural Activity ◽  
Resting State ◽  
Blood Oxygen Level Dependent ◽  
Diurnal Variations ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Healthy Human

scholarly journals Measurement of renal tissue oxygenation with blood oxygen level-dependent MRI and oxygen transit modeling

2014 ◽  
Vol 306 (6) ◽  
pp. F579-F587 ◽  
Author(s):  
Jeff L. Zhang ◽  
Glen Morrell ◽  
Henry Rusinek ◽  
Lizette Warner ◽  
Pierre-Hugues Vivier ◽  
...  
Keyword(s):  
Tissue Oxygenation ◽  
Human Subjects ◽  
Blood Oxygen Level Dependent ◽  
Renal Tissue ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Healthy Human ◽  
Bold Mri ◽  
Before And After

Blood oxygen level-dependent (BOLD) MRI data of kidney, while indicative of tissue oxygenation level (Po2), is in fact influenced by multiple confounding factors, such as R2, perfusion, oxygen permeability, and hematocrit. We aim to explore the feasibility of extracting tissue Po2 from renal BOLD data. A method of two steps was proposed: first, a Monte Carlo simulation to estimate blood oxygen saturation (SHb) from BOLD signals, and second, an oxygen transit model to convert SHb to tissue Po2. The proposed method was calibrated and validated with 20 pigs (12 before and after furosemide injection) in which BOLD-derived tissue Po2 was compared with microprobe-measured values. The method was then applied to nine healthy human subjects (age: 25.7 ± 3.0 yr) in whom BOLD was performed before and after furosemide. For the 12 pigs before furosemide injection, the proposed model estimated renal tissue Po2 with errors of 2.3 ± 5.2 mmHg (5.8 ± 13.4%) in cortex and −0.1 ± 4.5 mmHg (1.7 ± 18.1%) in medulla, compared with microprobe measurements. After injection of furosemide, the estimation errors were 6.9 ± 3.9 mmHg (14.2 ± 8.4%) for cortex and 2.6 ± 4.0 mmHg (7.7 ± 11.5%) for medulla. In the human subjects, BOLD-derived medullary Po2 increased from 16.0 ± 4.9 mmHg (SHb: 31 ± 11%) at baseline to 26.2 ± 3.1 mmHg (SHb: 53 ± 6%) at 5 min after furosemide injection, while cortical Po2 did not change significantly at ∼58 mmHg (SHb: 92 ± 1%). Our proposed method, validated with a porcine model, appears promising for estimating tissue Po2 from renal BOLD MRI data in human subjects.

scholarly journals Differential Modulating Effect of Acupuncture in Patients With Migraine Without Aura: A Resting Functional Magnetic Resonance Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Shanshan Liu ◽  
Shilei Luo ◽  
Tianwei Yan ◽  
Wen Ma ◽  
Xiangyu Wei ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Therapeutic Effect ◽  
Resting State ◽  
Migraine Without Aura ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Functional Magnetic Resonance ◽  
Blood Oxygen Level ◽  
Migraine Group

Introduction: Migraine is a recurrent neurological disorder, the symptoms of which can be significantly relieved by acupuncture. However, the central mechanism via which acupuncture exerts its therapeutic effect in migraine is unclear. The aim of this study was to compare the differences in regional homogeneity (ReHo) between patients with migraine without aura (MwoA) and healthy controls (HCs) and to explore the immediate and cumulative therapeutic effect of acupuncture in patients with MwoA using resting-state functional magnetic resonance imaging (fMRI).Methods: The study subjects were 40 patients with MwoA and 16 matched HCs. The patients with MwoA received acupuncture on 2 days per week for 6 weeks for a total of 12 sessions followed by 24 weeks of follow-up. The primary clinical efficacy outcomes were the number of days with migraine and the average severity of headache. Secondary outcomes were the Migraine-Specific Quality of Life Questionnaire, Self-Rating Anxiety Scale, and Self-Rating Depression Scale scores. In the migraine group, resting-state blood-oxygen-level-dependent fMRI scans were obtained at baseline and after the first and 12th acupuncture sessions to measure the ReHo value. In the HCs, only a baseline resting-state blood-oxygen-level-dependent fMRI scan was obtained.Results: Compared with the control group, the migraine group had a significantly lower ReHo value in the cerebellum, which increased after the first acupuncture session. Long-term acupuncture significantly improved migraine symptoms and mood with a therapeutic effect that lasted for at least 6 months. After 12 acupuncture sessions, there were significant increase of cerebellum and angular gyrus in the migraine group.Conclusion: These findings suggest that migraine is related to cerebellar dysfunction. Acupuncture can relieve the symptoms of migraine, improve dysfunction of cerebellum, and activate brain regions involved in modulation of pain and emotion The cumulative therapeutic effect of acupuncture is more extensive and significant than its immediate effect.

scholarly journals Evaluating Cognitive Relationships with Resting-State and Task-driven Blood Oxygen Level-Dependent Variability

2021 ◽  
Vol 33 (2) ◽  
pp. 279-302
Author(s):  
Peter R. Millar ◽  
Beau M. Ances ◽  
Brian A. Gordon ◽  
Tammie L. S. Benzinger ◽  
John C. Morris ◽  
...  
Keyword(s):  
Task Performance ◽  
Resting State ◽  
Attentional Control ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Bold Signal ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Age Related ◽  
And Task

Recent functional magnetic resonance imaging studies have reported that moment-to-moment variability in the blood oxygen level-dependent (BOLD) signal is positively associated with task performance and, thus, may reflect a behaviorally sensitive signal. However, it is not clear whether estimates of resting-state and task-driven BOLD variability are differentially related to cognition, as they may be driven by distinct sources of variance in the BOLD signal. Moreover, other studies have suggested that age differences in resting-state BOLD variability may be particularly sensitive to individual differences in cardiovascular, rather than neural, factors. In this study, we tested relationships between measures of behavioral task performance and BOLD variability during both resting-state and task-driven runs of a Stroop and an animacy judgment task in a large, well-characterized sample of cognitively normal middle-aged to older adults. Resting-state BOLD variability was related to composite measures of global cognition and attentional control, but these relationships were eliminated after correction for age or cardiovascular estimates. In contrast, task-driven BOLD variability was related to attentional control measured both inside and outside the scanner, and importantly, these relationships persisted after correction for age and cardiovascular measures. Overall, these results suggest that BOLD variability is a behaviorally sensitive signal. However, resting-state and task-driven estimates of BOLD variability may differ in the degree to which they are sensitive to age-related, cardiovascular, and neural mechanisms.

scholarly journals Resting-State Blood Oxygen Level-Dependent Functional MRI: A Paradigm Shift in Preoperative Brain Mapping

2015 ◽  
Vol 93 (6) ◽  
pp. 427-439 ◽  
Author(s):  
Eric C. Leuthardt ◽  
Monica Allen ◽  
Mudassar Kamran ◽  
Ammar H. Hawasli ◽  
Abraham Z. Snyder ◽  
...  
Keyword(s):  
Functional Mri ◽  
Brain Mapping ◽  
Resting State ◽  
Paradigm Shift ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level
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