Pad´e quantification of malignant and benign ovarian MRS data - Signal Processing in MRS with Biomedical Applications - page 291

CONVERGENCE of TOTAL SHAPE SPECTRA (MALIGNANT) ; FFT (Left) , FPT (−) (Right) ; FID LENGTH : N/M, N = 1024, M = 8 − 32

Fourier Absorption Total Shape Spectrum Pade Absorption Total Shape Spectrum

4000

B 0 14.1T

N/32 = 32 (N = 1024)
FFT

≈ B 0 14.1T

N/32 = 32 (N = 1024)
FPT (−)

≈

Malignant Malignant 20

2000 Lac

1000

Gln

15

500

300

Val

Glc

200

10

100

Lys

Ala

50

5

30

20

Crn

Cr

10

0

5

Met

3

−5

2

1

−10 0.5

5 4 3 2 1.5 1 5 4 3 2 1.5 1

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

Fourier Absorption Total Shape Spectrum Pade Absorption Total Shape Spectrum

120

4000

B 0 14.1T

N/16 = 64 (N = 1024)
FFT

≈

B 0 ≈ 14.1T
N/16 = 64 (N = 1024)
FPT (−)

Lac

Malignant

Malignant

2000

100

1000

Gln

500

Ala

Lys

80

300

Converged

Val

Thr

200

Glc

60 100

Crn Iso

Met

50

Cr

30

40

Cho

20

10

20

5

3

2

0

1

−20 0.5

5 4 3 2 1.5 1 5 4 3 2 1.5 1

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

Fourier Absorption Total Shape Spectrum Pade Absorption Total Shape Spectrum

120

4000

B 0 14.1T

N/8 = 128 (N = 1024)
FPT (−)

≈

B 0 14.1T

N/8 = 128 (N = 1024)
FFT

≈

Lac

Malignant

Malignant

2000

100

1000

80

Gln

500

Ala

Lys

Val

300

Converged

60 Glc Thr

200

100

40

Crn Iso

50

Met

Cr

20

2 30

Cho

0

10

5

−20

3

2

−40

1

−60 0.5

5 4 3 2 1.5 1 5 4 3 2 1.5 1

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

FIGURE 9.3
Convergence of absorption total shape spectra for the malignant ovarian case
using input data derived from Ref. [343]. The left panels correspond to the
FFT and the right panels to the FPT. The signal lengths are N/32 = 32 (top
panels (i), (iv)), N/16 = 64 (middle panels (ii), (v)), and N/8 = 128 (bottom
panels (iii), (vi)), where N is the full signal length (N = 1024).