The purpose of this experiment is to observe the diffusion coefficient of agarose solution as a function of temperature during the process of gel formation. The focus is on understanding how liquids become semi organized or semi-solid by monitoring dynamically with diffusion quantitative MRI the liquid-to-gel phase transition of pure agarose as a function of gel concentration. Four different concentrations of agarose solutions were allowed to cool down while scanning dynamically with 3 T MRI scanner (Achieva, Philips Medical Systems, Cleveland, OH) with diffusion qMRI, 70 dynamics with 56 seconds dynamic time. The 1%, 2%, 3%, and 4% agarose solutions were prepared by pouring agarose powder in distilled water and heating the solutions until they reached the boiling point ~80°C and completely dissolved. Then, scanning the phantoms dynamically as these cooled down immediately after preparation. A single axial slice diffusion-weighted-imaging turbo-spin-echo (DWI-TSE) pulse sequence was used. The diffusion versus time (temperature) curves of different agarose solutions show a distinct phase transition region characterized by a hump of increased diffusion. The diffusion coefficient as a function of time (temperature) curves of all the four concentrations shows similar behaviors with a phase transition characterized by a hump shaped at about 24 minutes at which time the gelation phase transition begins. These results may be useful for testing theoretical models of the NMR diffusion coefficient properties during liquids transforming to semi organized or semi solid
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/14315 |
| Date | 22 January 2016 |
| Creators | Kaifi, Reham Essam |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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