背景:虽然健康大脑温度的波动已经在数周至数月的时间内进行了调查,较短时间段内的动态不太清楚。
目的:确定健康志愿者大脑温度在约1小时时间尺度上的生理波动。
方法:前瞻性。
方法:30名健康志愿者(15名女性;26±4岁)。
UNASSIGNED:3T;T1加权磁化准备的快速梯度回波(MPRAGE)和通过绝热选择性重聚焦(sLASER)单体素光谱进行的半局部化。
方法:从N-乙酰天冬氨酸和水之间的化学位移差来计算脑温度。为了评估脑温度和脑体温度差的扫描内可重复性,128个光谱瞬变被分为两组64个光谱。使用两个时间段评估了扫描间的可重复性,相隔1-1.5小时。
方法:使用分层线性混合模型来计算扫描内和扫描间相关性(Rw和Rb,分别)。在P≤0.05时测定显著性。值报告为平均值±标准偏差。
结果:在扫描之间观察到大脑温度的显着差异(-0.4°C),但体温稳定(P=.59)。除一名受试者外,所有受试者的大脑温度(37.9±0.7°C)均高于体温(36.5±0.5°C)。脑温度(Rw=0.95)和脑-体温差异(Rw=0.96)的扫描内相关性很高。在扫描之间,脑温度(Rb=0.30)和脑-体温差异(Rb=0.41)的变异性都很高.
结论:在~1小时的时间尺度上观察到大脑温度的显著变化。高短期可重复性表明温度变化似乎是由于生理学而不是测量误差。
方法:2技术效果:第一阶段。
While fluctuations in healthy brain temperature have been investigated over time periods of weeks to months, dynamics over shorter time periods are less clear.
To identify physiological fluctuations in brain temperature in healthy volunteers over time scales of approximately 1 hour.
Prospective.
A total of 30 healthy volunteers (15 female; 26 ± 4 years old).
3 T; T1-weighted magnetization-prepared rapid gradient-echo (MPRAGE) and semi-localized by adiabatic selective refocusing (sLASER) single-voxel spectroscopy.
Brain temperature was calculated from the chemical shift difference between N-acetylaspartate and water. To evaluate within-scan repeatability of brain temperature and the brain-body temperature difference, 128 spectral transients were divided into two sets of 64-spectra. Between-scan repeatability was evaluated using two time periods, ~1-1.5 hours apart.
A hierarchical linear mixed model was used to calculate within-scan and between-scan correlations (Rw and Rb , respectively). Significance was determined at P ≤ .05. Values are reported as the mean ± standard deviation.
A significant difference in brain temperature was observed between scans (-0.4 °C) but body temperature was stable (P = .59). Brain temperature (37.9 ± 0.7 °C) was higher than body temperature (36.5 ± 0.5 °C) for all but one subject. Within-scan correlation was high for brain temperature (Rw = 0.95) and brain-body temperature differences (Rw = 0.96). Between scans, variability was high for both brain temperature (Rb = 0.30) and brain-body temperature differences (Rb = 0.41).
Significant changes in brain temperature over time scales of ~1 hour were observed. High short-term repeatability suggests temperature changes appear to be due to physiology rather than measurement error.
2 TECHNICAL EFFICACY: Stage 1.