ColonCa – Medical ColonCa – Medical BackgroundBackground

ColonCa – Medical ColonCa – Medical BackgroundBackground 3. Most common Ca3. Most common Ca

2. Common Ca leading to death2. Common Ca leading to death 11% of all new cancers/year11% of all new cancers/year Sequence Adenoma – Carcinoma Sequence Adenoma – Carcinoma

acceptedaccepted Colonoskopy = gold standard – Colonoskopy = gold standard –

BUT:BUT:

3D Visualization of the 3D Visualization of the Colon:Colon:

3D Visualization of the 3D Visualization of the Colon:Colon:

CT Pneumocolon „Interactive Slicing“ „Fly through“ (CT-

colonoscopy)) Virt. DissectionVirt. Dissection

„„CT Pneumocolon“CT Pneumocolon“„„CT Pneumocolon“CT Pneumocolon“

„„Interactive Interactive Slicing“Slicing“

„„Interactive Interactive Slicing“Slicing“

„„Fly Through“Fly Through“„„Fly Through“Fly Through“

Problems - Problems - General:General:

Problems - Problems - General:General:

Post processing of cross Post processing of cross sectional data:sectional data:- time consumingtime consuming- hardware intensiv (expensive!)hardware intensiv (expensive!)- specialized staff necessaryspecialized staff necessary

Problems - CT Problems - CT colonoscopycolonoscopy

Problems - CT Problems - CT colonoscopycolonoscopy

Path planning for automated Path planning for automated „fly through“ complicated and „fly through“ complicated and even operator dependenteven operator dependent

Endoscopic view display just a Endoscopic view display just a small proportion of the colonic small proportion of the colonic surface -> Ante and - surface -> Ante and - retrograde views necessaryretrograde views necessary

What do you wanna have What do you wanna have for CT - colonoscopy?for CT - colonoscopy?

What do you wanna have What do you wanna have for CT - colonoscopy?for CT - colonoscopy? Inspection of total colonic Inspection of total colonic

surface surface Fast toolFast tool Minimal interactionMinimal interaction No operator influenceNo operator influence Easy and quick to reportEasy and quick to report (Hardware independent)(Hardware independent)

„„Virtual Virtual dissection“dissection“

„„Virtual Virtual dissection“dissection“

Stretch the colon and cut it Stretch the colon and cut it along it‘s longitudinal axis along it‘s longitudinal axis similiar to the pathologist‘s similiar to the pathologist‘s tabletable

„„Virtual Virtual dissection“dissection“

„„Virtual Virtual dissection“dissection“

„„Virtual dissection“ Virtual dissection“ - How to do?- How to do?

„„Virtual dissection“ Virtual dissection“ - How to do?- How to do?

Data aquisitionData aquisition Segmentation - Fuzzy Segmentation - Fuzzy

connectedconnected Extraction of the centerline Extraction of the centerline

(Skeletonisation - Thining)(Skeletonisation - Thining) Calculation of the cross Calculation of the cross

sectionssections „ „Remapping“ to 2DRemapping“ to 2D

Virt.Diss. - Data AquisitionVirt.Diss. - Data AquisitionVirt.Diss. - Data AquisitionVirt.Diss. - Data Aquisition

MRDCTMRDCT- Slice thickness 2.5mmSlice thickness 2.5mm- Reconstruction: 1.25mm Reconstruction: 1.25mm

slice thickness, increment slice thickness, increment 0.5 - 1.0mm (~600-700 0.5 - 1.0mm (~600-700 images)images)

Virt.Diss. - Cross Virt.Diss. - Cross sectionssections

Virt.Diss. - Cross Virt.Diss. - Cross sectionssections

Virt.Diss. - Remapping Virt.Diss. - Remapping Virt.Diss. - Remapping Virt.Diss. - Remapping Constant Angle Constant Angle

SamplingSampling- No distortion in the y No distortion in the y

direction but adds area direction but adds area distortion.distortion.

- Can miss objects.Can miss objects.- No sense of “size”.No sense of “size”.- The surface is not sampled The surface is not sampled

uniformallyuniformally

Virt.Diss. - RemappingVirt.Diss. - RemappingVirt.Diss. - RemappingVirt.Diss. - Remapping Perimeter SamplingPerimeter Sampling

- Surface Sampled uniformally.Surface Sampled uniformally.- No missing elements. If No missing elements. If

sample step small enough.sample step small enough.- Area Preservation.Area Preservation.- Deformation in the y direction-Deformation in the y direction-

ShrinkingShrinking- Deformation increasing with Deformation increasing with

distance to the vertical center distance to the vertical center line.line.

Phantoms - TechnicalPhantoms - TechnicalPhantoms - TechnicalPhantoms - Technical

Phantoms - CadavericPhantoms - CadavericPhantoms - CadavericPhantoms - Cadaveric

Phantoms - CadavericPhantoms - CadavericArtific. Polyps (n=13)Artific. Polyps (n=13)Phantoms - CadavericPhantoms - CadavericArtific. Polyps (n=13)Artific. Polyps (n=13)

Filename: image.691 Table Position: -506.09 Size(Trans, Cor, Sag): 12.9 * 15 * 11.4 Protrusion(Trans, Sag, Cor): 13.8 * 13.8 * 11.2

Phantoms - CadavericPhantoms - CadavericArtific. Polyps (n=13)Artific. Polyps (n=13)Phantoms - CadavericPhantoms - CadavericArtific. Polyps (n=13)Artific. Polyps (n=13)

Filename: image.580 Table Position: -450.09 Size(Trans, Cor, Sag): 6.8 * 4.8 * 3.6 Protrusion(Trans, Sag, Cor): 2.6 * 1.6 * 0

Results - Techn. PhantomResults - Techn. PhantomResults - Techn. PhantomResults - Techn. Phantom

Results - Results - Cadaveric Cadaveric PhantomPhantom

Results - Results - Cadaveric Cadaveric PhantomPhantom

Results - Results - Cadaveric Cadaveric PhantomPhantom

Results - Results - Cadaveric Cadaveric PhantomPhantom

Results - Cadaveric Results - Cadaveric PhantomPhantom

Results - Cadaveric Results - Cadaveric PhantomPhantom

Constant Angle Sampling Perimeter Sampling

Results - Cadaveric Results - Cadaveric PhantomPhantom

Results - Cadaveric Results - Cadaveric PhantomPhantom

Polyps appear Polyps appear - as bumpsas bumps- as asymmetric as asymmetric

broadening of foldsbroadening of folds Time:Time:

- Operator 10minOperator 10min- Total time: 2hTotal time: 2h

Results - Results - DiverticulitisDiverticulitis

Results - Results - DiverticulitisDiverticulitis

Results - Medical Results - Medical EvaluationEvaluation

Results - Medical Results - Medical EvaluationEvaluation

2 Observer, 13 Polyps:2 Observer, 13 Polyps:- Sensitivity: 12/13 = 92.3%Sensitivity: 12/13 = 92.3%- Interob. Agreement: 11/13 = 84.6%Interob. Agreement: 11/13 = 84.6%- Pos.pred.Value: 75-80%Pos.pred.Value: 75-80%

Each Observer overlooked 1 Each Observer overlooked 1 Polyp: Polyp: - 3.9 * 5.0mm3.9 * 5.0mm- 3.5 * 2.5mm3.5 * 2.5mm

Conclusion Conclusion VirtDissVirtDiss

Conclusion Conclusion VirtDissVirtDiss Virt. Dissection of the Colon Virt. Dissection of the Colon

seems seems to be to be possible within a reasonablepossible within a reasonable

timeframetimeframe Operator interaction minimalOperator interaction minimal

(<10min), total time about 2h(<10min), total time about 2h Graz enviroment plattform Graz enviroment plattform

independentindependent Easy to report, performance Easy to report, performance

excellentexcellent Clinical experience until now Clinical experience until now

limitedlimited

OutlookOutlookOutlookOutlook Using the depth map enhance the image using image processing.

Contour detection.Curvature detection.

OutlookOutlookOutlookOutlook

„„TroubelshhootinTroubelshhootingg Tool“ Tool“

„ „Fecal Tagging“ Fecal Tagging“ – for easier – for easier patient patient preparationpreparation