Processing Micro CT Bone Processing Micro CT Bone Density ImagesDensity Images

NASA SHARP Student: Paul NelsonNASA SHARP Student: Paul Nelson NASA Mentor: John DaPonte Ph. D.NASA Mentor: John DaPonte Ph. D.

Team Members: Michael Clark, Elizabeth Wood, Thomas Sadowski, Paul ThomasTeam Members: Michael Clark, Elizabeth Wood, Thomas Sadowski, Paul Thomas

Southern Connecticut State University (SCSU), Computer Science DepartmentSouthern Connecticut State University (SCSU), Computer Science DepartmentSuny Stonybook University Suny Stonybook University NASA SHARP Program NASA SHARP Program

Project OverviewProject Overview

6 sets of high resolution (10.5µm), 8 sets of low resolution (17.5µm) image stacks of approximately 86 micro CT mouse images of trabeculae before and after exposure to weightlessness

Iterative deconvolution, no pre-processing and Gaussian blur.

Iterative deconvolution was qualitatively better then Gaussian blur and no pre-processing

Provide quantitative verification of the qualitative findings through numerical evaluation of data obtained from a variety of programs

Original Image After a few programs including deconvolution

Current WorkCurrent Work

Areas of focus for this bone density study include the fractal dimension, entropy enhancement (EME), bone area, bone thickness, SMI , and BV/TV

A majority of these parameters have already been collected for high/low resolution images

Calculations BackgroundCalculations Background

Bone Volume/Tissue Volume (BV/TV)= Total Bone Volume Total Tissue Volume Structure Model Index (SMI)= 6x(S’xV/S2)

S’=Change in Surface Area Caused by Dilation, S=Object Surface Area Before Dilation, V=Initial Volume

Bone Area Pixel Ratio (BAPR)= #of Bone Pixels In Threshold Image Total # of Pixels

Trabecular Thickness Pixel Ratio (TTPR)= # of Bone Pixels In Threshold Image # of Bone Pixels In Skelonized

Image

High/Low Res. Comparison DataHigh/Low Res. Comparison Data

5868(BL1)6125(AL1)

5870(BL2)6128(AL2)

5864(BM1)6119(AM1)

5866(BM2)6124(AM2)

Deconv

No Prep

Gauss0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

AVG Bone Area Ratio

Case(Before/After,More/Less,Pair#)

Low Res AVG Bone Area

5868(BL1)6125(AL1)

5870(BL2)6128(AL2)

5864(BM1)6119(AM1)

5866(BM2)6124(AM2)

Deconv

No Prep

Gauss0

2

4

6

8

10

12

AVG Bone

Thickness Ratio

Case(Before/After,More/Less,Pair#)

Low Res AVG Bone Thickness

2779(B1)2916(A1)

2964(B2)3106(A2)

2969(B3)3115(A3)

Deconv

No Prep

Gauss0

1

2

3

4

5

6

7

8

9

10

AVG Bone

Thickness Ratio

Case(Before/After,Pair#)

High Res AVG Bone Thickness

2779(B1)2916(A1)

2964(B2)3106(A2)

2969(B3)3115(A3)

Deconv

No Prep

Gauss0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

AVG Bone Area Ratio

Case(Before/After,Pair#)

High Res AVG Bone Area

High/Low Res. ConclusionsHigh/Low Res. Conclusions The average bone thickness for the low resolution

images showed a slight thinning for deconvolution and greater thickening by the Gaussian

The deconvolved data was closer to the data with no pre-processing

For the high resolution images this feature is further shown because the Gaussian was thickened greatly and the deconvolved averages to about the same as the no pre-processing

The average bone area for the low resolution image showed trends similar to average bone thickness

This difference is not as large for the Gaussian as in the large for deconvolution in the high resolution images.

BV/TV Graphs and ConclusionsBV/TV Graphs and Conclusions

5864(BL1)6119(AL1)

5866(BL2)6124(AL2)

5868(BM1)6125(AM1)

5870(BM2)6128(AM2)

Deconv

Not Deconv

0.00

0.50

1.00

1.50

2.00

2.50

3.00

SM

I #

Case(Before/After,More/Less,Pair#)

SMI # Pre Processing Method Comparison

5864(BL1)6119(AL1)

5866(BL2)6124(AL2)

5868(BM1)6125(AM1)

5870(BM2)6128(AM2)

Deconv

Not Deconv

0.000

5.000

10.000

15.000

20.000

25.000

30.000

35.000

BV

/TV

(%

)

Case(Before/After,More/Less,Pair#)

BV/TV % Pre Processing Method Comparison

For BV/TV the bone loss is lower for those mice that experienced more bone loss and higher for those that experienced less bone loss

After suspension occurs, BV/TV always decreases The SMI appears inversely related to the BV/TV

according to these graphs

Future WorkFuture Work

To date, the fractal dimension values have yet to be compiled. Theses parameters will continue to be analyzed to identify any trends that might allow for the separation of more from less bone loss and before and after experiencing weightlessness.

A planned future parameter of study is connectivity analysis.

The EndThe End