T2 distribution mapping profiles with phase-encode MRI

Two 1-D phase-encode sequences for T 2 mapping, namely CPMG-prepared SPRITE and spin-echo SPI, are presented and compared in terms of image quality, accuracy of T 2 measurements and the measurement time. The sequences implement two different approaches to acquiring T 2 -weighted images: in the CPMG-prepared SPRITE, the T 2 -weighting of magnetization precedes the spatial encoding, while in the spin-echo SPI, the T 2 -weighting follows the spatial encoding. The sequences are intended primarily for T 2 mapping of fluids in porous solids, where using frequency encode techniques may be problematic either due to local gradient distortions or too short T 2 . Their possible applications include monitoring fluid-flow processes in rocks, cement paste hydration, curing of rubber, filtering paramagnetic impurities and other processes accomplished by changing site-specific T 2 .