Quantifying the Brain Metabolism Underlying Task-Based BOLD Imaging
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 24
- 试验地点
- 2
- 主要终点
- Brain positron emission tomography (PET) imaging signals
研究概览
简要总结
The investigators will be studying brain glucose and oxygen metabolism using hybrid PET/fMRI imaging to better understand how decoupling between brain glucose and oxygen metabolism relates to the processing of unpredictable sensory signals.
详细描述
The proposed research consists of one experiment, combining positron emission tomography (PET) and magnetic resonance imaging (MRI) techniques to simultaneously estimate the cerebral metabolic rates of glucose (CMRglc) and oxygen (CMRO2), and their ratio (oxygen:glucose index; OGI). These outcome measures will be collected in the context of a behavioral intervention presenting subjects with predictable and unpredictable stimuli, and attended and unattended stimuli. Functional PET uses a slow infusion of 2-[18F]-fluro-deoxyglucose (FDG) to estimate regional CMRglc, measuring relative changes in radiotracer uptake between blocks of task and rest. Dual-calibrated fMRI uses a sequence of hyperoxic (increased O2) and hypercapnic (increased CO2) challenges, along with a specialized sequence of MRI scans (estimating cerebral blood flow and blood-oxygen level-dependent signal) to estimate absolute CMRO2.
All subjects will be scanned, and each will complete the same behavioral intervention. First, the investigators will aim to assess the reliability of this hybrid imaging technique by having subjects complete two identical scan sessions. Second, the investigators will deliver a behavioral intervention to test the relationship between stimuli predictability, CMRglc, CMRO2, and OGI.
This experimental design is capable of producing effects observable in single subjects, and prior studies using fPET and dual-calibrated fMRI have produced effect sizes that our sample size is more than adequate to detect.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 21 Years 至 35 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Adults aged 21-
- •No contraindications to MRI or PET scanning.
- •Right-handed.
- •Fluent to speak, read, and understand English.
排除标准
- •Adults unable to consent
- •Contraindications to fMRI scanning and PET scanning (including the presence of a cardiac pacemaker or pacemaker wires, metallic particles in the body, vascular clips in the head or previous neurosurgery, prosthetic heart valves, claustrophobia)
- •Inability to lie motionless in the scanner
- •Pregnancy, seeking or suspecting pregnancy, or breastfeeding
- •History of major head trauma
- •Intracranial lesion
- •Cardiovascular disorders, including heart disorders or high blood pressure [>155/95]
- •Breathing problems such as severe asthma, emphysema, or pulmonary disease
- •Bleeding disorder, or use of anticoagulants
- •Bladder obstruction, urinary problems, or history of impaired elimination
- •Known kidney or liver problems
- •Past severe COVID-19 infection
- •Intestinal blockage
- •Raynaud syndrome
- •Peripheral nerve injury
- •Current or recent use of medications (neurological or psychiatric) affecting brain function
- •Current or past history of major medical, neurological, or psychiatric condition
- •Current or past history of chronic pain (assessed at the discretion of PI)
- •Current smoker
- •Body mass index above 35
- •Research-related radiation exposure exceeds current Radiology Department guidelines
- •Lack of current health insurance coverage
- •Employed under the direct supervision of the investigators conducting the research
- •Unwilling or unable to cooperate with breathing maneuvers required during the gas challenge
- •Respiratory or cardiac limitations to breathing at 20 L/min
研究组 & 干预措施
Behavioral intervention
Subjects are presented with a simultaneous sequence of faces and spoken words. Face stimuli include a representative sample of realistic faces across a range of ages. Spoken word stimuli are simple nouns spoken by a single female speaker.
干预措施: (Un)predictable and (un)attended stimuli (Behavioral)
结局指标
主要结局
Brain positron emission tomography (PET) imaging signals
时间窗: after PET image analysis and with study completion, an average of 1 year
Changes in glucose metabolism will be quantified from brain PET images
Functional magnetic resonance imaging (fMRI) signals
时间窗: after fMRI image analysis and with study completion, an average of 1 year
Changes in oxygen metabolism will be quantified from dual-calibrated fMRI
Oxygen-glucose index
时间窗: after PET/fMRI image analysis and with study completion, an average of 1 year
Ratio of cerebral metabolic rates of glucose and oxygen from PET and fMRI signals
次要结局
未报告次要终点
研究者
Christin Y. Sander, PhD
Assistant Professor
Massachusetts General Hospital