University of Twente Student Theses
Development of a Myocardial Perfusion Tube Phantom: Analysis of Tissue perfusion by contrast kinetics
Saravanan, i Adharshna (2020) Development of a Myocardial Perfusion Tube Phantom: Analysis of Tissue perfusion by contrast kinetics.
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Abstract: | Background - Cardiovascular Disease is the most common cause of death worldwide. An important subclass is Coronary Artery Disease (CAD) which causes angina and myocardial infarction. Myocardial Perfusion Imaging (MPI) plays a major role in diagnosing CAD. Although MPI is of crucial importance, validation and standardization of the available methods is still limited. Our previous study has developed myocardial perfusion phantom to evaluate the multimodal quantitative MPI. Though their analysis results of Arterial Input function were good yet, the retention time of the tracer was shorter in phantom on comparison with the retention time of the tracer. Aim - The main purpose of this study is to resemble the physiological tissue perfusions by contrast kinetics. Thus, our project aims to prolong the residence time of the contrast agent (CA) in the systems (Myocardial Perfusion Tube Phantom and Pharmacokinetic (PK) Compartment models). Methods - Based on a novel 3D printed myocardial perfusion phantom (prototype 1) that was developed earlier, we investigated three concepts which we name them as “Myocardial Perfusion Tube phantoms”, to prolong the residence time of the CA. These are incorporated later into the arc shaped myocardial segments of the latest version of the 3D printed myocardial perfusion phantom (prototype 2) and include the following designs: (1) Basic tube phantom (BTP); (2) Membrane module filled tube phantom (20 Twisted type with 20 membrane modules or fibres (20TMMTP) and 10 Normal type with 10 fibres (10NMMTP) ); (3) Mixed tube phantoms (MTP).This report comprises three different types of studies. Prior to these Studies, various types of designs of the tube phantoms were proposed and designed using the Solid Works Software. Study 1 describes the development and the testing of the myocardial perfusion tube phantoms. To determine the residence time of the CA in different types of tube phantoms, Iodine-based CA was injected into the flow setup by varying several parameters like the flow rate and the dosages of the CA. The distribution of the CA inside the different types of tube phantoms were observed by taking an average of the pixel values in the region of interest (along y-axis) and plotting it over time (along x-axis). This plotted curve is known as Time Intensity Curves (TICs). Study 2 involves the simulation of the pharmacokinetic (PK) compartmental models and the goal is to identify the suitable model which could imitate the drug kinetics in myocardial segments. This was done by varying the dosages of the drug (CA) inside the different types of compartmental models. The concentration of the drug (along y-axis) is plotted over time (along x-axis) and this graph is named as Time Concentration Curves (TCCs). The TCCs, which was obtained through this study helped us to visualize the drug distribution within the compartments. The comparison of both the experimental results (TICs) and the simulation results (TCCs) that was obtained by varying the dosages (3ml, 5ml, 7ml) was investigated in Study 3. The final obtained results from study 3 are compared with the results of the previous study (Prototype 1). Results - In Study 1, 20TMMTP showed longer residence time of CA compared to all the other types of tube phantoms. Reproducibility experiments which was conducted for the BTP and MTP showed good reproducibility. Study 2 simulation results showed that the two-compartment PK model have longer residence time of the drug (CA) on compared to the one-compartment model. The Time Concentration curves (TCCs) which were obtained using two-compartment model through this study helped us to conclude that, The higher the concentration of the drug in the tissue, greater the residence time of the drug. Study 3 results supported Study 1 results (Experimental results by Varying the dosages of the drug (CA)), by comparing them with the Study 2 interpretations (Simulation results). At last, these results were compared with the previous study (prototype 1) and it was observed that the 20TMMTP, MTP and Two-compartment PK model showed longer residence time of CA/drug and closely resembles the patient Time Activity Curves (TACs). Conclusion - We have designed and developed different types of myocardial perfusion tube phantoms that allows reproducible and efficient simulations of the myocardial perfusion. Overall, we have successfully resembled the physiological tissue perfusions by contrast kinetics to a greater extent. |
Item Type: | Essay (Master) |
Faculty: | EEMCS: Electrical Engineering, Mathematics and Computer Science |
Subject: | 30 exact sciences in general |
Programme: | Biomedical Engineering MSc (66226) |
Link to this item: | https://purl.utwente.nl/essays/82821 |
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