MRI Technologistabout 8 years ago

PSIR

PSIR (or Real IR) stands for Phase Sensitive Inversion Recovery and is typically used to improve the delineation of gray and white matter. In addition, the sequence provides high contrast-to-noise ratio (CNR) between MS lesions and normal tissue. TI value of PSIR sequence is selected at 350-600 ms. PSIR preserves the information about Mz polarity, with more negative values rendered increasingly darker (figure). While using this technique it is important to use the phase sensitive reconstruction (real). Figure shows a coronal T1 PSIR sequence. Scalp fat is the brightest substance and CSF the darkest. Background air is rendered a mid-shade of gray. Phase sensitive reconstruction is also used>