Imaging of water and fat fractions in high-field MRI with multiple slice chemical shift-selective inversion recovery.
Fat and water fractions were quantified at high field using a chemical shift-selective inversion recovery (CSS-IR) sequence to address the major difficulties encountered at high field by phase-sensitive techniques used for fat/water discrimination. Water- and fat-suppressed images were perfectly registered, which is a prerequisite for quantification. Immunity of the inversion pulse to B(1) field modulations and off-resonance effects was tested for two adiabatic inversion pulses, with hyperbolic secant and asymmetric hyper-pulse waveforms. Taking into account adiabaticity, immunity to off-resonance, radiofrequency power requirements, and specific absorption rate, the former was chosen. A close correlation was found between fat content measured by CSS-IR at 4.7 T (R(2)= 0.97, P < 0.001) and 9.4 T (R(2)= 0.99, P < 0.05) and that measured by Soxhlet extraction. Different sources of bias (low signal-to-noise ratio, magnetization transfer effect) are discussed. J. Magn. Reson. Imaging 2000;12:488-496.
Laurent
W M
WM
Structures Tissulaires et Interactions Moléculaires, INRA-Theix, 63122 Saint-Genès-Champanelle, France.
Bonny
J M
JM
Renou
J P
JP
D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D002417:Cattle; D008055:Lipids / Q000032:analysis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D008962:Models, Theoretical; D018482:Muscle, Skeletal / Q000737:chemistry; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014867:Water / Q000032:analysis*
D008055:Lipids; D014867:Water