A. Masumoto et al., ANALYSIS OF INTRAMEDULLARY CELL-DENSITY BY MRI USING THE MULTIPLE SPIN-ECHO TECHNIQUE, American journal of hematology, 55(3), 1997, pp. 134-138
Analysis of the intramedullary cell distribution by magnetic resonance
imaging (MRI) using conventional techniques involves subjectively int
erpreting images and estimating the cell distribution on the basis of
signal intensity characteristics. In recent years, attempts have been
made to achieve more precise analysis by new techniques, including che
mical shift imaging. The multiple spin-echo (MSE) technique offers som
e advantages over conventional MRI. Since it allows measurement of the
transverse magnetization decay curve at 32 or more points, it is capa
ble of separating several tissue components with different relaxation
times. In addition, this technique can be used with MRI instruments ha
ving a static magnetic field as low as 1.0 Tesla, In the present study
, the intramedullary cell density was assessed by MRI using the MSE te
chnique in 4 patients with aplastic anemia (AA), 4 patients with myelo
dysplastic syndrome (MDS), and 5 normal subjects. The water component
of the marrow (with a short relaxation time) and the fat component (wi
th a long relaxation time) were separated from each other by analyzing
MR images obtained using the MSE technique, and the signal intensity
ratio of the 2 components was calculated. The ratio was significantly
higher in the AA group than in the other groups (AA vs. MDS, P = 0.020
9, AA vs, normal controls, P = 0.0143). The present technique appears
promising for quantitative assessment of the intramedullary cell densi
ty. (C) 1997 Wiley-Liss, Inc.