What is the measure for TR in MRI typically expressed as?

The measure for TR, or repetition time, in MRI is typically expressed in milliseconds. TR refers to the time between successive pulse sequences applied to the same slice of tissue in an MRI examination. Since many MRI sequences take place rapidly, especially in high-resolution imaging or in sequences optimized for speed, milliseconds provide a more granular and practical unit of measurement.

Using milliseconds allows radiologists and technicians to fine-tune imaging protocols more effectively, ensuring that the parameters are optimal for achieving high-quality images. This precision is critical given that variations in TR can affect image contrast and the overall quality of the MRI. While seconds and microseconds are units of time, they are not as commonly used in MRI contexts for TR because the timeframes involved in the imaging process typically dictate the use of milliseconds. Therefore, milliseconds is the standard measure for TR in MRI settings.