| Summary: | 碩士 === 高雄醫學大學 === 醫學影像暨放射科學系碩士班 === 104 === The liver is the largest internal organin the abdomen.The liver can decompose and store many nutrients via intestinal absorption to maintain human body’s function properly as well as filter and decompose toxic waste in the blood.One could not survive without the liver. Liver cancer has high blood flow and is one of the world''s top five causes of death.The composition and vascularity of liver cancer is quite inhomogeneous. Angiogenesis occurs when tumors grow. Hence, tumor growth can be evaluated by inspectingthe angiogenesis oftumors. Currently, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted imaging (DWI) and T2 fast spin echo (T2FSE) techniques are commonly used in assessing tumor growth. DCE-MRI is the most commonly used technique in clinical MRI for diagnosing tumors. Thesignal intensity (SI) changes over time after the injection of contrast agents can be usedto evaluate the tumorangiogenesis. DWI is afunctional MRI (fMRI) to observe the extent of water molecules’ diffusion caused by the thermal motion of water molecules. DWI can reflect the pathologic changes of living tissues by quantitating apparent diffusion coefficients (ADC). T2FSE MRI produces small motion and susceptibility artifacts so that high quality MR images can be achieved. Enhancement ratios (ER), ADC values and T2FSE SI of the normal liver, VX2 liver tumor and the normal muscle of New Zealand rabbits were evaluated longitudinally in this study. The results showed that a large amount of angiogenesis occurred in the surroundings of the VX2 tumors and tumor growth and cell necrosis led to changes in the water contentand ADC values of local tumor tissues. The ER, ADC and T2FSE SI of the VX2 tumor increased continuously at the 7th, 14th, 21th and 28th days after tumor implantation in the liver of New Zealand rabbits. There were significant differences in ER, ADC and T2FSE signal intensity among the 7th, 14th, 21th and 28th days (p< 0.05).
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