Bimonthly Meeting on Oct. 10, 2008 Metabolic Concentrations and Ratios of Brain Tissue Amarjeet...

Bimonthly Meeting on Oct. 10, 2008

Metabolic Concentrations and Ratios of Brain Tissue

Amarjeet Bhullar

We have compared metabolite ratios, calculated using different methods:

• Directly Generated by Functool [F1]

• Using Metabolites Concentration [F2]

• Gaussian Function Overlapped on metabolite peak with Baseline correction

• Gaussian Function Overlapped on metabolite peak with Baseline+Noise correction

Baseline Correction

Baseline corrects separately each individual spectral point in spectrumBy calculating and subtracting a Spline through each points for smoothing.

If smoothing width is non zero, takes its average value, which is very small =zero

In most of our spectrum baseline exists at zero

Baseline+Noise Correction

Metabolite ppm range Image range

Choline 3.16-3.32 67-77

Creatine 2.94-3.10 80-90

NAA 1.94-2.10 147-158

Lipid and lactate 1.50-0.90 187-221

Noise=Average value of after removing of four peaks

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#20

50 100 150 200 250

0

200

400

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

Voxel # 20, I0.4

50 100 150 200 250

0

200

400

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

Voxel # 20, I0.4

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#19

50 100 150 200 250

0

200

400

Real SpectrumS

ign

al (

MR

Un

its)

Image Number

Voxel # 19, I0.4

50 100 150 200 250

0

200

400

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

Voxel # 19, I0.4

50 100 150 200 2500

300

600

900 Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

Voxel # 16, I0.4

50 100 150 200 2500

300

600

900 Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

Voxel # 16, I0.4

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#16

Chemical Information on Voxel # 16, 19, 20

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#26

50 100 150 200 2500

300

600

900

1200

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

Voxel # 26, I0.4

50 100 150 200 2500

300

600

900

1200

Real SpectrumS

ign

al (

MR

Un

its)

Image Number

Voxel # 26, I0.4

50 100 150 200 2500

300

600

900

1200Voxel # 25, I0.4

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#25

50 100 150 200 2500

300

600

900

1200Voxel # 25, I0.4

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#24

50 100 150 200 250

-600

-400

-200

0

200

Real SpectrumSig

nal

(M

R U

nit

s)

Image Number

Voxel # 24, I0.4

50 100 150 200 250

-600

-400

-200

0

200

Real SpectrumSig

nal

(M

R U

nit

s)

Image Number

Voxel # 24, I0.4

Chemical Information on Voxel # 24, 25, 26

50 100 150 200 250-800

-600

-400

-200

0

Voxel # 31, I0.4

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#31

50 100 150 200 250-800

-600

-400

-200

0

Voxel # 31, I0.4

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#30

50 100 150 200 250

0

300

600

900

1200

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

Voxel # 30, I0.4

50 100 150 200 250

0

300

600

900

1200

Real Spectrum

Sig

nal

(M

R U

nit

s)

Image Number

Voxel # 30, I0.4

0.0

0.6

1.2

1.8

2.4

3.0

Cho/NAA

Met

abol

ite

Rat

ios

F1 F2 Baseline Corection Baseline+Noise Corection

Cho/Cr

V#27

50 100 150 200 250

-200

0

200

400

600

Real Spectrum

Voxel # 27, I0.4

Sig

nal

(M

R U

nit

s)

Image Number50 100 150 200 250

-200

0

200

400

600

Real Spectrum

Voxel # 27, I0.4

Sig

nal

(M

R U

nit

s)

Image Number

Chemical Information on Voxel # 27, 30, 31

Metabolite Ratios Cho/Cre

0.0

0.4

0.8

1.2

1.6

2.0

Voxel #

Cho

/Cre

F1 F2 Our Calculation

I0.4

Conclusion:

There is no significant difference between our calculation and Functool.

Suggestions are welcome