Intermediate
Technical
IVT
field inhomogeneity
Spatial variation in the magnetic field strength across the MRI scanner bore that causes signal loss and geometric distortion.
Full Definition
Field inhomogeneity refers to unwanted spatial variations in the main magnetic field (B0) or radiofrequency field (B1) within the MRI scanner. These variations can arise from hardware imperfections, patient-specific factors like tissue interfaces, or external magnetic sources. Field inhomogeneity causes signal dropout, geometric distortion, and intensity variations that can compromise image quality and quantitative measurements, particularly in functional and diffusion MRI studies.
Usage
Usage note: Distinguish between B0 and B1 inhomogeneity when precision is required; often simply called 'field inhomogeneity'.
In Context
- "Field inhomogeneity near the frontal sinuses caused significant signal dropout in the orbitofrontal cortex." — fMRI data quality assessment
- "Shimming procedures were performed to minimize field inhomogeneity before data acquisition." — Scanning protocol
Also known as
B0 inhomogeneity
field variation
magnetic field distortion
Contrasted with
field homogeneity
uniform field
Don't confuse with
susceptibility artifact
chemical shift