Summary: | 碩士 === 高雄醫學大學 === 醫學影像暨放射科學系碩士班 === 105 === Magnetic resonance imaging (MRI) is better than other clinical diagnosis in several characteristics, like non-invasiveness, non-ionizing radiation, and great contrast of soft tissues. T2 relaxation time is one of the characteristics of tissues. Different tissues have different T2 relaxation time. It is an important indicator for evaluation of tissue lesions. This study set up an animal model using immunodeficient nude mice implanted with human''s liver hepatocellular carcinoma cells (HEPG2). The mice were scanned using a 1.5 T clinical MRI scanner with a high-resolution wrist coil to obtain T2 and T2* relaxation times of liver, kidney, muscle and tumor. The tumor had higher signals in T2-weighted MR images. The contrast between the tumor and muscle increased with echo time. The T2 relaxation times of the liver, left renal cortex, right renal cortex, left renal medulla, right renal medulla, leg muscle, and the tumor were 30.8 ± 3.3 ms, 54.3 ± 4.7 ms, 57.4 ± 7.2 ms, 119.4 ± 20.3 ms, 123.6 ± 29.8 ms, 32.3 ± 0.9 ms and 57.1 ± 7.4 ms respectively. The T2* relaxation times of the liver, left renal cortex, right renal cortex, left renal medulla, right renal medulla, leg muscle, and the tumor were 20.8 ± 5.7 ms, 46.5 ± 9.7 ms, 59.4 ± 16.3 ms, 143.1 ± 49.5 ms, 137.7 ± 83.7 ms, 13.4 ± 3.7 ms and 13.5 ± 3.6 ms respectively. T2 and T2* can be used for quantitative analysis of tissue changes and play an important role in the early diagnosis, lesion progress prediction, and treatment following.
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