MEASUREMENT OF T1 AND T2 IN MR SPECTROSCOPIC EVALUATION OF FATTY LIVER
Bydder G, Middleton M, Bydder M, Schwimmer J, Sirlin C
Accurate MR Spectroscopic (MRS) liver fat quantification requires correction for relaxation effects. Average literature-based relaxation values may be used, but given patient variability, direct measurement may be preferable. Alternatively, sequences may be used that avoid these dependencies. We compared different MRS methods to measure T1 and T2 of liver fat and water. We measured T2 consistently and reliably with breath-hold spectroscopy at multiple values of TE. However, T1 could not be measured reliably using variable TR or variable flip-angle techniques. This suggests that fat fraction may best be determined with sequences that avoid T1 dependence, using patient-specific measured T2 correction.