X-Ray for Agricultural Applications

X-Ray for X-Ray for Agricultural Agricultural ApplicationsApplications

Dave UtrataDave UtrataIowa State UniversityCenter for NDEIPRT Company Assistance – NDE Group

Alexandra Black, Brett BarnesAlexandra Black, Brett BarnesIowa State UniversityThree Rivers Technical ConferenceThree Rivers Technical Conference

Elk River, MNElk River, MNAugust 3-4, 2010August 3-4, 2010

Presentation OutlinePresentation OutlineBackground of Company

Assistance program◦Current efforts, interests

Review of progress in three areas◦Detection of frost damage in maize

seeds◦Distinguishing between haploid/hybrid

condition in corn seeds◦Imaging of root development

Summary◦Applications, potential, challenges

Three Rivers Tech Conf - 3-4 Aug 2010

IPRT Company Assistance

Technology Commercialization - accelerate commercialization of ISU and company-developed technology through research and development assistance.

Technical Assistance - provide short-term, no-cost technical assistance to Iowa companies in materials and nondestructive evaluationnondestructive evaluation.

Iowa State University – Institute for Physical Research and Testing


Operational Guide – NDE Operational Guide – NDE GroupGroup Explain & demonstrate the principles of

various inspection methods

Perform feasibility studies to determine which NDE method will work best for your application

Develop inspection protocol for new designs or evaluate current inspection procedures

Provide information on sources of equipment, testing laboratories

Help manufacturers become educated consumers of NDE


Beyond the usual suspects of fabricated metal, joining operations, current NDT practitioners…

“Round up the usual suspects”


Nontraditional applications of Nontraditional applications of NDENDEDetection of frost damage in maize

(corn) seed – Seed Science Institute, ISU

Distinguishing between haploid v. hybrid conditions in corn – Agronomy Dept. ISU

Visualizing root growth – North Central Regional Plant Introduction Station


Detection of frost damage in seed


Brief background of some work Brief background of some work in fieldin fieldX-ray used to look into potential for

characterizing seeds◦ Often adapted from medical systems, very

often restricted to film◦ “Soft” x-rays

Feasibility of digital high speed evaluation demonstrated using industrial system with pattern recognition for sorting


Detection of frost damage in Detection of frost damage in corn seedcorn seedCan x-ray methodologies provide

useful assessment of seed structure, viability?◦ Use modern industrial equipment:

microfocus X-ray tube, all digital imaging◦ Differentiate between control group (no

frost damage) and damaged maize seeds (artificial frost cycle)

B37 inbred line, male parent IRF311, hybrid 3 Moisture content at harvest 50%

◦ Provide more rapid alternative to current sectioning & staining (tetrazolium) test


ResultsResults

Using Flat Panel◦Seven samples from both

control and frost damaged groups were examined


Control seedsControl seeds


Frost damaged seedsFrost damaged seeds


Qualitative difference Qualitative difference apparent between groups – apparent between groups – loss of internal structureloss of internal structure

Next: quantitative analysis of Next: quantitative analysis of images to remove subjective images to remove subjective evaluationevaluation Three Rivers Tech Conf - 3-4 Aug

2010

X-ray Luminance Profiles of X-ray Luminance Profiles of Maize Seeds MethodMaize Seeds Method

Line profile used to see if there is a numerical difference in the luminance profiles between a control corn seed and a frost damaged seed


TrendsTrends

In general, the luminance profile of a good seed with no frost damage is more erratic then the smoother bad seed’s profile

This trend presumably reveals frost damage to internal seed structure

FrostDamage

Control


Further analyses ofFurther analyses ofmaize seed X-raysmaize seed X-raysThe luminance profiles were

exported to spreadsheetsTwo methods were used to

numerically separate the control from the frost damaged seeds

◦Large Difference◦Large Slope


Analysis : Large Analysis : Large DifferenceDifference

In the profile shown here, there are 4 differences in the “valid” region (internal seed features) that are larger then the threshold.

Total Range

Large Difference Threshold = (Scale Factor)*(Total Range)

Large Difference Threshold

1 2

3

4

Valid Region


Analysis : Large SlopeAnalysis : Large Slope For example,

the profile of this seed has 5 Large Slopes in the valid region.

Valid Region

1

2

5

34 6


Results : Large DifferenceResults : Large Difference

There are typically more “large differences” within radiographs of control seeds than for frost damaged seeds.

Large Difference Data

Sample ControlFrost

Damage1 10 12 12 33 12 04 7 05 4 16 0 47 11 2

Avg 8 1.5Scale Factor = 0.055

FrostDamage

Control


Results : Large SlopeResults : Large Slope

There are more “large slopes” on average within radiographs of control seeds than for frost damaged seeds

Large Slope Data

Sample ControlFrost

Damage

1 40 20

2 27 18

3 43 10

4 21 18

5 13 9

6 19 40

7 42 27

Avg 29.2 20.3

Slope Threshold = 10

FrostDamage

Control


ConclusionsConclusionsThe internal structure of maize

seeds may be revealed using standard industrial radiographic equipment

The adverse effects of frost damage were observable in this small study, independent of seed knowledge or significant manipulation of test conditions


Problems with analysisProblems with analysisThe threshold multiplier has to be

adjusted to maximize the divergence in counts/core counts between averaged results for good and bad learning sets◦ .055 used initially, .038 probably better

Similarly, the large derivative threshold is chosen to maximize this difference◦ 10 used initially, 12 probably better

The “valid” region of interest was subjectively chosen


Positive modification Positive modification (attempts)(attempts)Change source to detector distance

◦Magnified image Structural variation seen in more detail over

greater pixel count◦Work at lower voltage (40 kV 25 kV)

Strive for contrast variation afforded by lower energies

More automated line profile placement◦Remove subjective analysis


New Seed RadiographsNew Seed Radiographs

Control Frost


Frost – SaturdayFrost – Saturday

Radiograph with Equator, Automatic & Manual Profiles Highlighted Line Profiles

Auto 1 Auto 2 Auto 3 Man.

Large Difference Counts

11 226 241 261

Large Slope Counts

1 5 1 1

Auto 1

Equator

ManualAuto 3

Auto 2


Large Difference Results SummaryLarge Difference Results SummaryLarge Difference Count Table

Auto 1 Auto 2 Auto 3 ManualCtrl-Sun 216 228 250 233Ctrl-Mon 12 14 9 214Ctrl-Tues 7 15 28 25 Frost-Thur - 13.5 16 15 176 129Frost-Thur - 11 36 41 48 35Frost-Fri 80 240 276 99Frost-Sat 11 226 241 261

Difference is not as clear as Difference is not as clear as was earlier believed; was earlier believed;

faulty logic due to magnified faulty logic due to magnified image?image?


Large Slope Results SummaryLarge Slope Results SummaryLarge Slope Count Table

Auto 1 Auto 2 Auto 3 ManualCtrl-Sun 1 1 1 1Ctrl-Mon 4 1 1 1Ctrl-Tues 1 1 1 2 Frost-Thur - 13.5 1 1 1 1Frost-Thur - 11 1 1 1 2Frost-Fri 1 1 1 1Frost-Sat 1 5 1 1

Difference is not as clear as Difference is not as clear as was earlier believed; was earlier believed;

faulty logic due to magnified faulty logic due to magnified image?image?


Radiographic detection of frost Radiographic detection of frost damagedamage

Differentiation is certainly possible◦To what degree?

50% moisture at frost is no big challenge

Algorithm/logic needs to be refined◦Slope/difference thresholds need

account for morphology changes over higher pixel countThree Rivers Tech Conf - 3-4 Aug

2010

Haploid & hybrid seedsHaploid & hybrid seeds The inducing of haploid corn from which to generate

more vigorous hybrid lines is desired◦ Currently takes six to eight generations of corn, or 3-4

years, to produce the inbred lines to cross for hybridization

Effective method for inducing haploids would reduce this time to one or two generations◦ Allow for the faster production of hybrid lines◦ Greater freedom to experiment with other seed attributes

Distinguishing between stained and unstained seeds (current method) takes a trained eye and much time

CT scans on seeds were performed◦ Embryos of the haploid seeds were ~7% smaller by

volume than the hybrid seeds


Comparison of Hybrid & Haploid Comparison of Hybrid & Haploid CollectionsCollections

Haploid Hybrid


Data Analysis ProcedureData Analysis Procedure

A section of the radiograph was selected and a histogram of that luminance data was generated

Two sections were analyzed for each sample:◦600 pixel diameter circle (not

adequate)◦Oval with 900 & 600 pixel major and

minor radiiThree Rivers Tech Conf - 3-4 Aug 2010

Haploid – Saturday – Haploid – Saturday – 600 x 900 600 x 900 pixel ovalpixel oval


Luminance profiles of Luminance profiles of Haploid and Hybrid SeedsHaploid and Hybrid Seeds


Do lower luminance values reflect smaller

embryos?

Results not definitiveResults not definitiveScatter in data may prove

analysis to be hopelessly clumsy

Is data showing density/volumetric info of interest?

Placement/size of measurement area still problematic


Interest in observing root Interest in observing root structurestructureCommercial system prohibitively

expensive

What can be done?


Styrofoam HolderStyrofoam HolderConfigured for two plantsConfigured for two plants


30 kV30 kVEnergy: 30 kVCurrent: 250 µASpot Size: SmallFPS: 1Window Average:

10Source to Detector

Distance: 26”Source to Sample

Distance: ~24”





Distance: 20”





Distance: 20”


Images of “Sprout & Grow”Images of “Sprout & Grow”with Bean & Pea plantswith Bean & Pea plants

Energy: 25 kVCurrent: 250 µASpot Size: SmallWindow Average: 10Source to Detector Distance: 24”


Sprout & Grow Holder – Front Sprout & Grow Holder – Front ViewView

A pea and bean seed grown in water and Styrofoam beads in half of the container.


Sprout & Grow Holder – Rear Sprout & Grow Holder – Rear ViewView


Sprout & Grow Holder – Front ViewSprout & Grow Holder – Front View

X-Ray Image

Optical Image


Sprout & Grow Holder – Rear ViewSprout & Grow Holder – Rear View

X-Ray Image

Optical Image


ConclusionsConclusionsX-ray imaging of roots quite

possible◦Use Styrofoam beads, not standard

growing media

Scale of imaging important◦Subtle initial growth or large

developed network


Overall conclusionsOverall conclusionsDigital

radiography is powerful tool for nontraditional applications

Communication of needs, tradeoffs necessary◦ Content revealed

v. inspection rate


Thank youThank you


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X-Ray for Agricultural Applications

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