J. Ma et al., A SINGLE-SCAN IMAGING TECHNIQUE FOR MEASUREMENT OF THE RELATIVE CONCENTRATIONS OF FAT AND WATER PROTONS AND THEIR TRANSVERSE RELAXATION-TIMES, Journal of magnetic resonance [1997], 125(1), 1997, pp. 92-101
Citations number
25
Categorie Soggetti
Physics, Atomic, Molecular & Chemical","Biochemical Research Methods
A two-component chemical-shift-imaging technique is described from whi
ch fat and water images can be obtained in a single scan and in the pr
esence of an inhomogeneous field. In addition, the method provides tra
nsverse relaxation rates R(2) and R(2)' separately for each of the spe
ctral components. The method is a combination and extension of the GES
FIDE [gradient echo sampling of FID and echo, J. Ma and F. W. Wehrli,
J. Magn. Reson. B 111, 61 (1996)] and the multipoint Dixon techniques.
It is based on sampling the descending and ascending portions of a Ha
hn spin echo with a train of gradient echoes which are spaced at one-h
alf of the chemical-shift modulation period. Processing of the complex
echo data, involving an automated phase unwrapping algorithm, affords
relative amplitudes and transverse relaxation rates of the two spectr
al components. An additional benefit of the method is its superior sig
nal-to-noise ratio resulting from echo summation. Applications targete
d and illustrated involve MRI osteodensitometry of trabecular bone in
the presence of varying fractions of hematopoietic and fatty bone marr
ow. (C) 1997 Academic Press.