JulienJulien Noel Noel –– North Star Imaging, Inc.North Star Imaging, Inc.

Computed TomographyComputed TomographyApplicationsApplications & New DevelopmentsNew Developments

Basics of Computed Basics of Computed TomographyTomography

Definition (Wikipedia)

“Computed Tomography (CT) […] is a medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an objectfrom a large series of two-dimensional X-ray images taken around a single axis of rotation.

The word "tomography" is derived from the Greek tomos (slice) and graphein (to write)”

1967 : The idea of a CT scanner is conceived by Godfrey Newbold Hounsfield.

1972 : The first commercially viable CT scanner was invented by Hounsfield in Hayes, England.

1979 : Nobel Prize in medicine for Hounsfield and Cormack.

33 mswide fan electron beam1284 detectorselectron beamFifth

10 ms / 3DCone-BeamMatrix 2DRotateSixth

1 secwide fan600~4800Rotate-fixedFourth

0.5 secwide fan256~1000Rotate-rotateThird

10 secnarrow fan3~52translate-rotateSecond

2.5 minpencil thin1~2translate-rotateFirst

min scan timebeamdetectorsconfigurationGeneration

Brief history

PRINCIPLE OF CT PRINCIPLE OF CT

2d Radiograph 2d CT Slice 3d CT Volume Rendering

3d CT Surface Rendering

CT systems

Main components of CT system

X-ray tube : minifocus (0.4 mm 4 mm) CT

microfocus (<1µm 10 µm) microCT

X-ray detector : Linear detector

Image Intensifier + CCD camera

Flat panel

Manipulator with 1 rotation axis

CT Software

Calibration

ReconstructionFiltered Back-Projection Algorithm (Feldkamp)

2D & 3D Visualisation

Measurements

Surface Extraction – Point cloud data set

ApplicationsApplications

Medical

Research Labs

Industry

Others e.g. museums

Aerospace, Aviation : E.g. turbine, carbon fiber, connectors, tailpipe

Automotive : E.g. cylinder head, piston, spark plug, injector

Electronics : Small electronic components. E.g. BGA solder joint.

Microdevices : E.g. spray nozzle

Medical Devices : E.g. Devices for asthmatics, Pacemaker, implants …

Food and seeds : E.g. piece of chocolate cake, broken glass in beverage

Diamonds : E.g. detecting defects in a diamond and finding the best way to cut it.

Nuclear : E.g inspect radioactive waste

Others : E.g. cigarettes

Polymers, plastics : E.g. plastic foam

Composite materials and metallic foams : E.g. composite material with glass fibers 10 to 12 micrometres in diameter

Wood and paper : E.g. piece of wood to visualize year periodicity and cell structure

Building materials : E.g. concrete after loading.

Geology : E.g. sandstone

Biomedical : E.g. Both dead and alive (in-vivo) rat and mouse scanning, Human skin samples, small tumors, mice bone for osteoporosis research.

Medical Industry

Research Labs

INDUSTRIAL USE OF CTINDUSTRIAL USE OF CTINDUSTRIAL USE OF CT

Research (material structure, new material analysis, density analysis …) – R&D / Research

Inspection / NDT (inclusions, cracks, porosities, displacement …) – Quality control

Reverse engineering / rapid prototyping (surface rendering, CAD) – Drawing/Design

Measurements – Metrology

Application #1Application #1

ResearchResearch

Plaster foam – size 10 x 4 mm

Wood samples

Application #2Application #2

InspectionInspection

Plastic Part

CT Application – Flaw Detection

Aluminum Casting Rendering

CT Application – Flaw Detection

Slice with Measured Porosity

CT Application – Flaw Detection

Surface Rendering Transparent

CT Application – Flaw Detection

Internal Surface Rendering with Porosity

CT Application – Flaw Detection

Surface Rendering with Lines

Aluminum Casting

BGA electronic component

Crimp – size 2,5mm

150 mm composite part

150 mm composite part

DemoDemo

Application #3Application #3

Reverse EngineeringReverse Engineering

• Map 3D volume creating a point cloud data set.

• Useful for model comparison, rapid prototyping, reverse engineering, flaw visualization and report production.

CT Software – Surface Mapping

CT Application – Rapid Prototyping

CT Application – Reverse Engineering

Export 3D volume file to surface STL, IGES, point clouds for CAD compatibility

50mm automobile brass plug

Spark plug –

Steel + ceramic

automobile industry

Wires – aerospaceindustry

Application #4Application #4

MeasurementsMeasurements

Turbine blade

Injector Nozzle

CT systemsCT systemsnew featuresnew features

Local CTLocal CT

CT Software – Local Tomography

• Reconstruct a portion of the 2D sequence data.

• Automatically follows the area of interest, not geometry.

CT Software – Local Tomography

Applications• Part does not allow for

needed geometric magnification.

• New area of interest is found after initial acquisition.

• Higher resolution reconstruction is required in a specific area of interest.

CT Software – Local Tomography

Result:• Highly magnified

reconstruction.• Relatively small

reconstruction volume.

• High resolution data in area of interest.

400 mm diam.

Composite aerospace sample

MultiMulti--angle CTangle CT

CT Software – Multi-reconstruction

• 360 degree radiographic acquisition is not needed to create a volumetric reconstruction.

• More data = Better results• Single acquisition sets of 120 degrees or less have

produced adequate reconstructions. Application dependent.

• Two or more acquisition sets can be combined for a singe volume.

CT Software – Multi-reconstruction

360 Degree Data 240 Degree Data 120 Degree Data

Ultra fast CTUltra fast CT

The benefit

512x512x512 voxel reconstruction = 16 seconds

(current software version = 7 minutes)

The application

20 x faster reconstruction

In-line CT

In-Line CT control

• Targeted control cycle ~ 30 sec

• Inspection or/and 3d metrology

• Fully automatic process

• Zero defect

Dedicated cabinet

Custom systems

CT upgrade

Service facility

Thanks for your attention !Thanks for your attention !Any question ?Any question ?

Computed TomographyComputed TomographyApplicationsApplications – new developmentsnew developments