MRI Liver Phantom for Transarterial Chemoembolization Simulation

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MRI Liver Phantom for Transarterial
Chemoembolization Simulation
Team Leader Benjamin Engel Communicator Eric
Printz BWIG Ryan Carroll BSAC Justin
Schmidt Client Dr. Wally Block,
Ph.D Departments of Biomedical Engineering
Medical Physics Advisor Dr. Bill Murphy,
Ph.D Department of Biomedical Engineering
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Overview

• Research Motivation
• Background Information
• Project Requirements
• General Design Approach
• Vascular Network Options
• Next Steps

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Research Motivation

• Hepatic metastases are a major cause of mortality
• Colorectal cancer and breast carcinoma
• Primary liver tumors
• Systemic chemotherapy treatment ineffective
• Response rate of 20
• 20 of tumors are surgically operable
• Targeted techniques improve results
• TACE procedures

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X-Ray Guided Technique

• Current procedure involves two step process
• Preoperative CT or MRI scan
• X-ray guided catheterization
• X-ray disadvantages
• Incomplete tumor location
• Not tolerated by patients with compromised kidney
  function
• Ionizing radiation
• 2 dimensional projections

http//content.answers.com/main/content/img/oxford
/Oxford_Body/019852403x.x-rays.3.jpg
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MRI Guided Technique

• High contrast, cross-sectional imaging technique
• Contrast enhancement under sampling techniques
  make real-time, dynamic images possible
• Active catheter tracking

Block, WF. 3D Real-Time MRI Imaging Grant. PHS
398/2590.
Result Improved tumor localization without the
need to deliver high doses of radiation to the
patient
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Liver Anatomy

• Eight Couinaud segments
• Branch from hepatic arteries
• 75 venous circulation
• 25 arterial circulation
• TACE focuses on arterial vasculature

Block, WF. 3D Real-Time MRI Imaging Grant. PHS
398/2590.
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Current Phantom
Left/Right Hepatic Arteries Connect to Liver
Aorta
Right Renal Artery

• Does not model liver
• Surrounded with opaque gel
• Artifacts caused by proximity of phantom edges to
  vasculature
• Connected to constant flow pump

Right Femoral Artery
Block, WF. 3D Real-Time MRI Imaging Grant. PHS
398/2590.
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Project Specifications

• Vasculature
• 8 couinaud segments
• Key abdominal arteries
• Material compatible with MRI
• Minimize image artifacts
• Four inches between enclosure and vasculature
• Port for catheter entrance into vasculature
• Active flow through vasculature
• Maneuverable by one person

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General Approach
Plexiglas Enclosure
Vascular Network
Fluid Manifold
Flow Pump
Catheter insertion port
1 Entrance Point
15 Exit Points

• R/L femoral
• Superior mesenteric
• R/L renal
• Left gastric
• Splenic
• 8 Couinaud segments

• Aorta

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Vascular Network Design Ideas

• Limitless variation
• Tygon tubing using plastic connectors
• Vascular junctions using barbed plastic
  connectors
• Limitation on achievable angles
• Tygon tubing using adhesive
• Silicone based epoxy
• Precise placement of branches
• Silicone wrapped mold
• Wax mold or 3D printed mold
• Apply silicone over mold
• Heat/saturate mold for removal
• Time constraint

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Liver Model
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Our Approach
Create Vasculature
Suspend within enclosure
Mark/construct enclosure
Return lines/ fluid manifold

• Create holes at junctions
• Adhere branches
• Mimic spatial relation

• Temporary attachment of vasculature to enclosure
  walls

• 24 X 18 X 8
• Mark entrance and exit points
• Drill exit and entrance holes
• Attach quick disconnect fittings
• Assemble enclosure walls

• Attach return lines to fittings
• Attach return lines to fluid manifold
• Attach fluid manifold to pump

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Questions?
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References
Block, WF. 3D Real-Time MRI Imaging Grant. PHS
398/2590. Vigen KK, Peters DC, Grist TM, Block
WF, Mistretta CA. Undersampled projection
reconstruction imaging for time-resolved
contrast-enhanced imaging. Magnetic Resonance in
Medicine. 200043170-176. Longmire WP, Tompkins
RK, Manual of Liver Surgery, Springer-Verlag,
1981 Shelley Medical Imaging Technologies. Rigid
Abdominal Aorta Product Details. Product Number
A-R-N-001. X-Ray Angiograph. http//content.answ
ers.com/main/content/img/oxford/Oxford_Body/019852
403x.x-rays.3.jpg Liver Model. Mevis-Distant
Services. http//www.mevis-distant-services.com/in
dex.php?id23
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Project Scope
Semester 1
Semester 2

• Rough/working vascular model
• Develop enclosure
• Single speed using current flow pump
• Safety and reliability testing
• Usability testing with interventional radiologists

• Improvement of 3D vascular network
• Integration of pulsatile flow through current
  flow pump
• Upgrade flow pump
• Development of gel/liquid that mimics T1/T2
  relaxation times
• Continued usability testing