Exact quantum-mechanical, Pad´e-based recovery of spectral parameters - Signal Processing in MRS with Biomedical Applications - page 112

RESIDUAL or ERROR SPECTRA in FPT (+) (Left) and FPT (−) (Right) ; FID LENGTH: N P = 180, 220, 260

Subtraction of 2 Spectra; FID Length: 1024, 180 Subtraction of 2 Spectra; FID Length: 1024, 180

12 12

8 8

N P = 180 B 0 =1.5T N P = 180 B 0 =1.5T

4 4

0 0

−4 −4

FPT (+) (1024) − FPT (+) (180) FPT (−) (1024) − FPT (−) (180) −8 −8

−12 −12

5 4 3 2 1 5 4 3 2 1

(i) Chemical shift (ppm) (iv) Chemical shift (ppm)

Subtraction of 2 Spectra; FID Length: 1024, 220 Subtraction of 2 Spectra; FID Length: 1024, 220

12 12

8 8

N P = 220 B 0 =1.5T N P = 220 B 0 =1.5T

4 4

0 0

−4 −4

FPT (+) (1024) − FPT (+) (220) FPT (−) (1024) − FPT (−) (220) −8 −8

−12 −12

5 4 3 2 1 5 4 3 2 1

(ii) Chemical shift (ppm) (v) Chemical shift (ppm)

Subtraction of 2 Spectra; FID Length: 1024, 260 Subtraction of 2 Spectra; FID Length: 1024, 260

12 12

8 8

N P = 260 B 0 =1.5T N P = 260 B 0 =1.5T

4 4

0 0

−4 −4

FPT (+) (1024) − FPT (+) (260) FPT (−) (1024) − FPT (−) (260) −8 −8

−12 −12

5 4 3 2 1 5 4 3 2 1

(iii) Chemical shift (ppm) (vi) Chemical shift (ppm)

FIGURE 3.7
Residual spectra or error spectra for absorption total shape spectra in the
FPT (+)

(left) and FPT (−)

(right) near full convergence for signal lengths

N P = 180, 220, 260.