TR
Pronunciation: tee-are
Also written as: TR — repetition time
Repetition time - the interval between successive radiofrequency pulse sequences in MRI.
Full Definition
TR (repetition time) is a fundamental MRI sequence parameter that defines the time interval between successive applications of the same radiofrequency pulse sequence. Measured in milliseconds, TR directly influences image contrast, acquisition time, and signal-to-noise ratio. Short TR values (typically <500ms) produce T1-weighted images with good anatomical detail, while long TR values (>2000ms) are used for T2-weighted imaging to highlight pathology. The selection of appropriate TR values is crucial for optimizing image contrast for specific clinical indications.
Usage
Usage note: Always capitalize TR when used as an abbreviation; use lowercase for repetition time.
In Context
- "The T1-weighted sequence was acquired with TR = 500ms and TE = 12ms." — Technical parameters documentation
- "Increasing the TR will improve T2 contrast but extend scan time." — Protocol optimization