MR Imaging

TLDR

Inversion recovery (IR) sequences are examined for their properties and clinical applications. IR sequence performance depends on repetition time, inversion time, echo time, encoding, data collection, and image processing, with various options demonstrated in normal and clinical CNS and body imaging. Short TI IR improves body imaging, medium TI aids brain localization and contrast enhancement, long TI assists pediatric imaging and tumour‑oedema separation, and fat or fluid suppression options are beneficial. Index terms include inversion recovery and nuclear magnetic resonance techniques.

Abstract

The properties of the inversion recovery (IR) sequence are considered and its use in clinical practice is illustrated. The effect of changing repetition time, inversion time (TI), and echo time; the method of data encoding; the type of data collection; and the method of image processing are analysed. Normal appearances and clinical examples in the central nervous system and the remainder of the body are used to illustrate the many options available with this sequence. The short TI IR sequence has advantages in magnetic resonance imaging of the body, and medium TI sequences are of value in localisation in the brain and in demonstrating contrast enhancement. Long TI sequences can be used in pediatrics and for separating tumour and oedema. Suppression or partial suppression of fat and fluid signals are two useful options with IR sequences. Index Terms: Inversion recovery–Nuclear magnetic resonance, techniques–Nuclear magnetic resonance.