11. Glossary¶
The Glossary provides short definitions of neuroimaging concepts as well
as brainprep specific vocabulary.
If you wish to add a missing term, please create an issue or open a Pull Request.
- BIDS¶
Brain Imaging Data Structure is a simple and easy to adopt way of organizing neuroimaging and behavioral data.
- BOLD¶
Blood oxygenation level dependent. This is the kind of signal measured by functional Magnetic Resonance Imaging.
- EPI¶
Echo-Planar Imaging. This is the type of sequence used to acquire functional or diffusion MRI data.
- fMRI¶
Functional magnetic resonance imaging is based on the fact that when local neural activity increases, increases in metabolism and blood flow lead to fluctuations of the relative concentrations of oxyhaemoglobin (the red cells in the blood that carry oxygen) and deoxyhaemoglobin (the same red cells after they have delivered the oxygen). Oxyhaemoglobin and deoxyhaemoglobin have different magnetic properties (diamagnetic and paramagnetic, respectively), and they affect the local magnetic field in different ways. The signal picked up by the MRI scanner is sensitive to these modifications of the local magnetic field.
- functional connectivity¶
Functional connectivity is a measure of the similarity of the response patterns in two or more regions.
- MNI¶
MNI stands for “Montreal Neurological Institute”. Usually, this is used to reference the MNI space/template. The current standard MNI template is the ICBM152, which is the average of 152 normal MRI scans that have been matched to the MNI305 using a 9 parameter affine transform.
- QA¶
Quality Assurance aimed at ensuring that acquired data meet predifined quality standards. QA focuses on detecting acquisition problems.
- QC¶
Quality Control defines a set of procedures used to identify, flag, or exclude data that do not meet predefined quality standards. QC focuses on detecting processing problems.
- RBM¶
Region-Based Morphometry is a morphometric method that quantifies tissue properties within predefined anatomical regions of interest (ROIs) instead of performing voxel-wise or surface-based analyses. RBM summarizes structural measures (e.g., gray matter volume, cortical thickness) at the regional level, enabling robust comparisons.
- resting-state¶
Resting state fMRI is a method of functional magnetic resonance imaging that is used in brain mapping to evaluate regional interactions that occur in a resting or task-negative state, when an explicit task is not being performed.
- SBM¶
Surface-Based Morphometry is a structural neuroimaging approach that analyzes cortical properties (such as thickness, surface area, curvature, and folding patterns) on the reconstructed cortical surface rather than in voxel space. SBM provides a detailed characterization of cortical morphology and is well suited for studying subtle anatomical differences across individuals or groups.
- VBM¶
Voxel-Based Morphometry measures differences in local concentrations of brain tissue, through a voxel-wise comparison of multiple brain images.
- vertex¶
A vertex (plural vertices) represents the coordinate of an angle face on a triangular mesh in 3D space.
- voxel¶
A voxel represents a value on a regular grid in 3D space.