Pad´e quantification of malignant and benign ovarian MRS data - Signal Processing in MRS with Biomedical Applications - page 295

CONVERGENCE of TOTAL SHAPE SPECTRA in FFT ; BENIGN (Left) , MALIGNANT (Right) ; FID LENGTH : N = 8192, 16384, 32768

Fourier Absorption Total Shape Spectrum Fourier Absorption Total Shape Spectrum

4000 4000

B 0 14.1T

N = 8192
FFT

≈ B 0 ≈ 14.1T

N = 8192
FFT

Benign

Malignant

2000 2000

1000 1000

500

500

300 300

200

200

100

100

50

50

30

30

20

20

10

10

5

5

3

3

2

2

1

1

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 Fourier Absorption Total Shape Spectrum

4000

4000

B 0 ≈ 14.1T
N = 16384
FFT

B 0 ≈ 14.1T

N = 16384
FFT

Benign Malignant

2000 2000

1000

1000

500 500

300

300

200

200

100

100

50

50

30

30

20

20

10

10

5

5

3

3

2

2

1

1

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 Fourier Absorption Total Shape Spectrum

4000 4000

B 0 14.1T

N = 32768
FFT

≈ B 0 ≈ 14.1T

N = 32768
FFT

Benign Malignant

2000 2000

1000 1000

500 500

300

Converged

300

Converged

200 200

100 100

50 50

30 30

20 20

10 10

5 5

3 3

2 2

1 1

0.5 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 9.5
Convergence of absorption total shape spectra via the FFT for the benign and
malignant ovarian cases using input data derived from Ref. [343]. The left
and right panels correspond to the benign and malignant case, respectively.
The signal lengths are N = 8192 (top panels), N = 16384 (middle panels)
and N = 32768 (bottom panels).