Inversion Recovery scan

Inversion Recovery is a Spin Echo pulse sequence with an initial 180° inversion pulse prior to the 90° pulse. Use IR sequences produce T1-weighted or fat-suppressed images, particularly in abdomen or extremities. This sequence is also used for very heavily weighted T1 brain images.

The initial 180° pulse is used to create magnetization in the negative Z axis. The period between the 180° and 90° pulse is the inversion time (TI). The time between the 90° and the echo is TE, similar to a Spin Echo sequence.

• The effectiveness of the IR fat suppression technique varies based on changes in magnetic field homogeneity.
• Do not use IR pulse sequences with contrast agents because enhancing pathology could be suppressed if the shortened T1 effect corresponds to the null point.

Table 1. IR PSD image legend

Number	Description
1	90°
2	180°
3	TE
4	TR
5	TI

The TI is the primary controller of image contrast. The TI value is determined by the time required for a tissue to recover from the negative longitudinal axis to the transverse plane. This time is the null point.

Table 2. Null point curve image legend

Number	Description
1	Null
2	Fat curve
3	Water curve
4	Transverse plane
5	Contrast reversal zone
6	TI

Use IR sequences to produce T1-weighted or fat-suppressed images, particularly in abdomen or extremities.

Table 3. Image legend

Number	Description
1	IR knee image
2	IR brain image

Consider this information when modifying Inversion Recovery scan parameters. For specific scan parameter values, select a protocol from your GE or Site library.

• Scan description: 2D Mode, IR pulse.