5-1 討論
本論文的研究目的係針對目前臨床上最常用的幾種脂肪抑制技術，脂 肪抑制自旋回訊、脂肪抑制快速自旋回訊，反轉回復快速自旋回訊及不對 稱回訊脂肪和水的重複分解與最小平方評估法之脂肪抑制效果進行比較評 估。實驗特別選擇於容易因解剖部位幾何形狀或是組成影響而造成脂肪抑 制不均勻的部位，如頸部與足踝區域。取得掃描影像後進行影像分析，比 較使用各種脂肪抑制技術掃描所得影像之影像品質，並且由放射師交叉判 讀與比對，比較各種脂肪抑制技術的效果及相關性。實驗結果得知，雖然 四種脂肪抑制波序皆無法抑制 100﹪的脂肪訊號。但不對稱回訊脂肪和水的 重複分解與最小平方評估法可獲得良好的水脂分離影像，期望本研究之完 成能在臨床診斷上提供更正確的脂肪抑制磁振造影影像，以利醫生判讀診 斷。
5-2 結論
根據研究結果，頻率選擇預飽和技術不管是應用於傳統自旋回訊或快 速自旋回訊波序，對頸部及足踝部位的造影都相當敏感，也就是脂肪抑制 很不均勻。相對來說，反轉回復自旋回訊則對此二部位之造影比較不敏感，
亦即脂肪抑制較前二者均勻。不對稱回訊脂肪和水的重複分解與最小平方 評估法為本研究探討之脂肪抑制方法中最佳的選擇，即使在磁場強度非常 不均勻處，如頭頸部與足踝，都能獲得良好的水脂分離效果。然而，IDEAL 的缺點則是需要更長的掃描時間和複雜的影像重建運算。
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