Advancing Virtual Colonoscopy to Practice

1. Advancing Virtual Colonoscopy to Practice Mark Wax MD, Arie Kaufman PhD, Jerome Liang PhD, and Kevin Kreeger MS

2. Advancing Virtual Colonoscopy to Practice • Introduction • Cited Limitations • Approach to Overcoming Obstacles • Conclusions

3. Colorectal Cancer Screening Guidelines(Gastroenterology, 1997) • Screening Modality • Safe • Acceptable • Available • Cost Effective

4. 3D Virtual Colonoscopy • An alternative endoscopic procedure for examining the inner surface of the human colon • Overcoming disadvantages of existing procedures

5. Virtual Colonoscopy Procedure 40 sec CT scan of patient’s abdomen Reconstruction of 3D colon model Pre-processing of colon model Interactive navigation inside colon

6. Advancing Virtual Colonoscopy to Practice • Introduction • Cited Limitations • Approach to Overcoming Obstacles • Conclusions

7. New England Journal of Medicine(Nov 11, 1999) • “A Comparison of Virtual and Conventional Colonoscopy for the Detection of Colorectal Polyps” H. Fenlon et. al, Boston University • “Virtual Colonoscopy - Promising but Not Ready for Widespread Use” J. Bond, Minneapolis VA

8. Cited Limitations • Patient Preparation • Bowel Cleansing • Technique • Gas distention of colon • Time to process data/images to determine whether optical colonoscopy is required

9. Cited Limitations • Image Interpretation • Time consuming • Steep learning curve • Technically inadequate studies • Retained stool/fluid • Contracted segments • Sensitivity/specificity

10. Cited Limitations • Cost • Expensive scanning hardware • Needs to be less than optical colonoscopy

11. Advancing Virtual Colonoscopy to Practice • Introduction • Cited Limitations • Approach to Overcoming Obstacles • Conclusions

12. Bowel Cleansing • Contrast Agents - Barium Sulfate, Gastrograffin • Low residue diet • Electronic Cleansing

13. Inner View of the Colon

14. Technique • Colon Distention • CO2 instead of room air • Fast reabsorbtion • Increased patient comfort • Collapsed colon segments • Glucagon • Supine and Prone Views

15. Image Interpretation • Steep Learning Curve • Similar to any new technology or procedure • Virtual fly-through interface mimics optical colonoscopy

16. User Interface

17. Time to Process Data and Interpret Images • Volume rendering with SGI and PC platforms • Navigation • Guided using colon centerline • Interactive with the click of a mouse

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19. Sensitivity/Specificity • Stool/Fluid tagging • Electronic Cleansing • Electronic Biopsy

20. Costs • Estimated cost - $200-$300 • Less than Medicare reimbursement for Abdominal and Pelvic CT ($410) • Less than Physician charges for optical colonoscopy ($700) • Only requires 10 minutes of CT scanning time • Increased utilization of CT scanners

21. Advancing Virtual Colonoscopy to Practice • Introduction • Cited Limitations • Approach to Overcoming Obstacles • Conclusions

22. Virtual Colonoscopy System • Technical Advances • Speed • Automation • Comfort • Cost effective • Future • System still evolving, not yet frozen • Large scale clinical trial