MR appearance and spectral features of injected ethanol in the liver : Implication for Fast MR-guided percutaneous ethanol injection therapy

Our goal was to evaluate several fast MR strategies for monitoring ethanol distributions so that percutaneous ethanol injection might be guided with MRI. Fast RF spoiled GRE sequences (SPGR) and T2-weighted rapid acquisition with relaxation enhancement (RARE) sequences with and without spectroscopic-quality water suppression techniques were assessed for their ability to depict the distribution of injected ethanol in ex vivo pig liver. A line scan Carr-Purcell-Meiboom-Gill spectroscopic imaging sequence was used to validate observations and measure spectral relaxation characteristics of the ethanol signal in liver. Injected deuterated ethanol was also tested as an alternative possibility to depict the distribution of ethanol. The water-suppressed T2-weighted RARE sequence depicted the distribution of ethanol better than other sequences. Deuterated ethanol appeared as a signal void on all sequences. Water-suppressed T2-weighted RARE sequences could be useful to rapidly monitor MR-guided PEI.