| Summary: | 碩士 === 中山醫學大學 === 生物醫學科學學系碩士班 === 100 === Global cancer statistics for 2011 by world health organization shows the highest liver cancer rates are found in Asia. In Taiwan, the information by department of health, the highest national cause of death at 2010 was cancer, and hepatic cancer was the second cause of death in all cancers. Among primary liver cancers, hepatocellular carcinoma (HCC) is one of the common hepatic cancers. There are several methods to detect HCC. Taking some blood to test the alpha feto protein and observing patient medical image by ultrasound or CT. In clinical, we use CT liver three phase to evaluate liver lesion. A recent development in CT was dual source technology. DSCT can get low energy image, high energy image and dual energy weighted image by use dual energy scanning. In image reconstruction, the current reconstruction method in CT is filtered back projection (FBP), but recently new methods, based on iterative reconstruction (IR) have been introduced. Our study collected HCC patients information and medical images after their underwent dual source CT liver three phase examinations, using single or dual energy scanning at arterial phase. In radiation dose, we multiplied the dose length product by CT conversion factor defined effective dose. In image quality, we reconstructed single and dual energy arterial images by FBP or IR with different kernels. We also reconstructed dual energy weighted image by different weighting factors at dual energy arterial phase. To analyze image quality by objective, we measured organs and tissues CT number by manual ROIs and calculated contrast by liver and lesion, noise, contrast to noise ratio and figure to merit. In subjective image quality, two radiologists recorded image scores by image noise, lesion conspicuity and overall image quality. In addition, we used image quality phantom to undergo single and dual energy arterial phase protocols. Reconstruction by FBP, IR and different weighting factors to analyzed objective image quality for phantom images and compared with patient’s analysis. Our study estimated clinical HCC image quality without increasing radiation dose by different image reconstruction techniques and calculated radiation dose in DSCT liver three phase using single or dual energy at arterial phase.
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