Table 2.
Effect of Filters on Quality of MR Spectra*
| RMS noisea | Linewidthb | Poor fitc | |
|---|---|---|---|
| No filter | 7.2 ± 1.7 | 5.02 ± 2.19 | 5.57% |
| Apodization | 4.5 ± 1.5 | 5.90 ± 2.20 | 5.82% |
| DSM | 3.4 ± 1.5 | 5.27 ± 2.17 | 3.94% |
*
Results from 44,695 MR spectra from 22 control subjects using no spectral filters, a Gaussian apodization filter of 1.3 Hz width, or DSM.
a
RMS: root mean square.
b
Linewidth in Hz.
c
Percentage of spectra in MRSI that did not meet following criteria: 1) linewidth between 1.9 and 11.1 Hz; 2) fitted resonance difference between MI and Cr between 0.43 and 0.63 ppm; and 3) fitted resonance difference between NAA and Cr between 0.97 and 1.05 ppm.