Mark Wax MD, Arie Kaufman PhD,

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Advancing Virtual Colonoscopy to Practice

• Mark Wax MD, Arie Kaufman PhD,
• Jerome Liang PhD, and Kevin Kreeger MS

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Advancing Virtual Colonoscopy to Practice

• Introduction
• Cited Limitations
• Approach to Overcoming Obstacles
• Conclusions

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Colorectal Cancer Screening Guidelines(Gastroente
rology, 1997)

• Screening Modality
• Safe
• Acceptable
• Available
• Cost Effective

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3D Virtual Colonoscopy

• An alternative endoscopic procedure for
  examining the inner surface of the human
  colon
• Overcoming disadvantages of existing
  procedures

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Virtual Colonoscopy Procedure

• 40 sec CT scan of patients abdomen
• Reconstruction of 3D colon model
• Pre-processing of colon model
• Interactive navigation inside colon

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Advancing Virtual Colonoscopy to Practice

• Introduction
• Cited Limitations
• Approach to Overcoming Obstacles
• Conclusions

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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

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Cited Limitations

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

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Cited Limitations

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

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Cited Limitations

• Cost
• Expensive scanning hardware
• Needs to be less than optical colonoscopy

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Advancing Virtual Colonoscopy to Practice

• Introduction
• Cited Limitations
• Approach to Overcoming Obstacles
• Conclusions

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Bowel Cleansing

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

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Inner View of the Colon
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Technique

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

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Image Interpretation

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

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User Interface
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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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Sensitivity/Specificity

• Stool/Fluid tagging
• Electronic Cleansing
• Electronic Biopsy

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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

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Advancing Virtual Colonoscopy to Practice

• Introduction
• Cited Limitations
• Approach to Overcoming Obstacles
• Conclusions

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Virtual Colonoscopy System

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