Image Processing Reference
In-Depth Information
1.5
1
0.5
0
9
8
7
6
5
4
3
2
1
chemical shift (ppm)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
98765432
1
0
chemical shift (ppm)
The effect of optimal water suppression (a) with a single pulse and (b)
with the three-pulse combination. The residual contribution of the water signal was sig-
nificantly lower in the measurement using the pulse combination.
FIGURE 11.10
suggested by Ogg et al. (10) for an optimal water suppression if different B1 and
T1 values of the water signal occur in the examined object. A strong saturation
of the water peak is obtained in a larger range of transmitter values in this case,
and the extent of water suppression for the optimal transmitter value is larger with
the three-pulse combination than with the one-pulse saturation (Figure 11.10): The
reason for the incomplete saturation with one pulse is the composite nature of
the water signal. It consists of several compartments with different relaxation
times. The result of the optimal water suppression obtained with one pulse shows
a superposition of these compartments. In Figure 11.10a, a part with a shorter
T2-relaxation time and, therefore, a broader peak shape, shows a residual signal,
whereas a component with a longer T2-relaxation time and a narrower line shape
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