Professional Technical IVT

EPI sequence

Pronunciation: ee-pee-eye

Also written as: EPI — echo-planar imaging

Echo-planar imaging pulse sequence used for rapid brain image acquisition in functional MRI.

Full Definition

Echo-planar imaging (EPI) is a fast MRI pulse sequence that enables rapid acquisition of brain images, making it the standard technique for functional neuroimaging. EPI sequences can capture entire brain volumes in 1-3 seconds, allowing real-time monitoring of brain activity during tasks or rest. However, EPI is susceptible to artifacts including susceptibility distortion, ghosting, and signal dropout, particularly in regions near air-tissue interfaces such as the orbitofrontal cortex and temporal poles.

Usage

Usage note: Use 'EPI sequence' rather than just 'EPI' for clarity in clinical contexts.

In Context

"The EPI sequence parameters included TR=2000ms and TE=30ms for optimal BOLD contrast." — MRI protocol specification
"Susceptibility artifacts in the EPI data required specialized correction algorithms." — Data quality assessment

Also known as

echo-planar imaging

Contrasted with

spin-echo sequence

Don't confuse with

GRE sequence FLASH sequence

echo planar imaging ← Back to glossary FDG-PET