Abstract
Abstract The physiological noise in the resting brain, which arises from fluctuations in metabolic‐linked brain physiology and subtle brain pulsations, was investigated in six healthy volunteers using oxygenation‐sensitive dual‐echo spiral MRI at 3.0 T. In contrast to the system and thermal noise, the physiological noise demonstrates a signal strength dependency and, unique to the metabolic‐linked noise, an echo‐time dependency. Variations of the MR signal strength by changing the flip angle and echo time allowed separation of the different noise components and revealed that the physiological noise at 3.0 T (1) exceeds other noise sources and (2) is significantly greater in cortical gray matter than in white matter regions. The SNR in oxygenation‐sensitive MRI is predicted to saturate at higher fields, suggesting that noise measurements of the resting brain at 3.0 T and higher may provide a sensitive probe of functional information. Magn Reson Med 46:631–637, 2001. © 2001 Wiley‐Liss, Inc.
Keywords
Affiliated Institutions
Related Publications
Functional connectivity in the motor cortex of resting human brain using echo‐planar mri
Abstract An MRI time course of 512 echo‐planar images (EPI) in resting human brain obtained every 250 ms reveals fluctuations in signal intensity in each pixel that have a physi...
Spontaneous Low-Frequency Fluctuations in the BOLD Signal in Schizophrenic Patients: Anomalies in the Default Network
Spontaneous low-frequency fluctuations in the blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (MRI) signal have been shown to reflect neural synchrony ...
Positron emission tomography and magnetic resonance imaging in the diagnosis and prediction of dementia
Abstract Background The diagnosis of dementia, along with the prediction of who will develop dementia, has been assisted by the development of the brain imaging techniques of ma...
Conceptual Processing during the Conscious Resting State: A Functional MRI Study
Abstract Localized, task-induced decreases in cerebral blood flow are a frequent finding in functional brain imaging research but remain poorly understood. One account of these ...
Enhanced Detection of Focal Brain Responses Using Intersubject Averaging and Change-Distribution Analysis of Subtracted PET Images
Intersubject averaging and change-distribution analysis of subtracted positron emission tomographic (PET) images were developed and tested. The purpose of these techniques is to...
Publication Info
- Year
- 2001
- Type
- article
- Volume
- 46
- Issue
- 4
- Pages
- 631-637
- Citations
- 635
- Access
- Closed
External Links
Social Impact
Social media, news, blog, policy document mentions
Citation Metrics
Cite This
Identifiers
- DOI
- 10.1002/mrm.1240