利用氟-18-去氧葡萄糖正子斷層掃描偵測腎臟細胞為原發或轉移之病灶，其敏感性及特異性仍有爭議。我們報告一個使用雙相氟-18-去氧葡萄糖正子斷層造影來確診腎臟細胞為肝臟轉移之病例。一位69歲的男性病患2年前因為左側腎臟細胞為接受腎臟切除術，最近以核磁共振造影追蹤時發現肝臟有多處新增病灶，因此被轉介進行全身氟-18-去氧葡萄糖正子斷層造影，結果顯示在延遲相影像中其病灶與背景之對比較例行中目明顯增強。因此，我們建議在使用氟-18-去氧葡萄糖正子斷層造影偵測腎臟細胞為肝臟轉移時，使用雙相掃描計算出病灶的滯留係數(retention index)可以作為判讀的重要指標。

Using 18F-FOG PET (FOG-PET) to detect primary or metastatic lesions of renal cell carcinoma is still controversial. We report a dual-phase FOG-PET scan of liver metastases from renal cell carcinoma. A 69-year-old male patient suffered from left renal cell carcinoma and received nephrectomy 2 years ago. He was referred for FOG-PET study because multiple new hepatic lesions were noted on his recent MRI images. The dual-phase FOG-PET images showed a significant increase in the tumor-to-background contrast in the delayed phase. It suggests that retention index (RI) may be a determinant in diagnosing metastatic hepatic lesions from renal cell carcinoma.