MRI Liver Phantom for Transarterial Chemoembolization Simulation Final Design Report December 12th 2008 Team Members: Benjamin Engel – Team Leader Eric Printz – Communicator Ryan Carroll – BWIG Justin Schmidt – BSAC Client Dr. Wally Block, PhD Departments of Medical Physics and Biomedical Engineering Advisor Dr. William Murphy, PhD Department of Biomedical Engineering Abstract Liver cancer in various forms is a major cause of mortality and current treatment methods are highly ineffective. Transarterial chemoembolization (TACE) is a chemotherapy delivery technique which improves the localization of treatment. Currently, TACE is guided through X-ray imaging but would benefit from utilizing real time 3D MRI. The purpose of this project was to create an MRI phantom of the liver and abdomen which would allow interventionalists to practice TACE catheterizations. The phantom that was created accurately depicts the eight Couinaud segments of the liver as well as key abdominal arteries. Initial tests indicate that the vasculature can withstand the maximum flow of the pump (3 L/min). Additionally, both the phantom vasculature and enclosure are water tight. Finally, the phantom produced minimal artifact allowing for accurate MR imaging. In the future, tube diameter adjustments along with the addition of pulsatile flow will enhance the flow characteristics of the phantom. Additional testing with interventional radiologists will be performed.2 Table of Contents Problem Statement…………………………………………………………………………. 2 Background information………………………………………………………………........ 2 Liver Cancer/Current Treatment…………………………………………………... 2 TACE (Transarterial Chemoembolization)……………………………………....... 5 X-ray DSA/MRI Techniques………………………………………………………... 6 Current Phantom…………………………………………………………………... 7 Design Requirements………………………………………………………………………. 8 Vascular Network Design Research/Methods……………………………………………... 11 Materials/Construction Methods…………………………………………………………… 13 Final Design………………………………………………………………………………... 14 Testing………………………………………………………………………………………18 Integrity Testing……………………………………………………………………. 18 MR Imaging Studies………………………………………………………………... 20 Future Work………………………………………………………………………………... 22 Conclusion…………………………………………………………………………………. 24 References………………………………………………………………………………….. 25 Appendix A: Cost Analysis………………………………………………………………... 26 Appendix B: Product Design Specifications……………………………………………….. 28Problem Statement The goal of this project is to develop and construct an MRI compatible liver phantom which represents the arterial vasculature of both the human liver and abdomen. This phantom will be utilized by interventional radiologists to simulate cancer treatments and practice catheterization procedures under the guidance of magnetic resonance imaging. The dual imaging suite at the University of Wisconsin Hospital is an excellent location for interventionalists to conduct MRI guided procedures due to the proximity of the X-ray machine, which they are familiar with. Training radiologists on the use of MRI as an effective imaging modality has the potential to increase the localization and effectiveness of transarterial chemoembolization procedures. Background Information Liver Cancer/Current Treatment Figure 1 – Liver metastases found in liver segment VII (above) and III (below) using MR imaging [4] Primary liver cancer and hepatic metastases of the liver represent a significant medical problem throughout the world. The liver is the most common site of metastatic tumor deposits in the body and hepatic metastases represent a major cause of mortality in patients with other malignant tumors [1]. Specifically, hepatic metastases are common in the case of both colorectal and breast cancer. In 20-30% of colorectal cancer cases, the liver is the only site of 3 4 metastases. Hepatic involvement in almost all forms of cancer is often indicative of a life threatening illness [2]. Depending on the primary site of cancer, 30-70% of patients who die from cancer have liver metastases present in their autopsy [3]. In addition to metastases, primary liver tumors in the form of hepatocellular carcinoma continue to be a major cause of death, especially in Asia [5]. For this reason, effective identification and treatment methods are necessary to improve a patient’s chance of survival when diagnosed with either primary liver cancer or hepatic metastases. Unfortunately, current treatment methods for liver cancer in its various forms are highly ineffective. The most promising hope for a cure is surgical resection. Five years after surgical resection of colorectal metastases, 40% of patients are alive, and 30% are disease free. However, in the case of colorectal liver metastases only 20% of all lesions are surgically operable leaving an enormous portion of patients to rely on systemic chemotherapy and radiation treatments [6]. While promising breakthroughs have been made in the localization of these treatments, systemic treatments continue to be extremely ineffective. For example, the response rate to the most commonly used chemotherapy agent (5-fluorouracil) in the treatment of hepatic metastases worldwide is only 20%. Survival rates for patients with unresected cancer vary based on the origin of the study; however, the following figures give a good indication of the ineffectiveness of systemic treatment: “1-year survival for solitary or limited liver metastases varies from 38 to 83%, whereas 3-year survival for solitary or limited metastases extends from 0 to 33%, and the figures for
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