正子斷層照影是一種特殊而先進的醫療技術，可以讓醫師利用其特性來分辨良性或惡性腫瘤，甚至是擴散性的腫瘤。而其臨床上的限制是由於正子斷層照影使用的放射性藥物是經由泌尿道排出，時常和泌尿道內的惡性腫瘤混淆不清，而造成判讀上的困擾。然而對於尿毒的病人，因為尿量稀少而能突顯出正子斷層照影的特殊造影，因此正子斷層照影用於尿毒的病人身上有其臨床上的特殊意義。我們報告三例（61歲女性，BUN/Cr:24/4.6；58歲女性，BUN/Cr:52/7.7；68歲女性，BUN/Cr:70/8.6）尿毒病例的診斷結果及臨床上的應用。

Positron emission tomography (PET) is a unique procedure that allows a physician to examine organs and tissues. PET imaging is very accurate in differentiating malignancies from benign growths, as well as showing the spread of malignant tumors. However, there are still some limitations when PET is applied to the examination of urological tract tumors because the secreted metabolic material passing through the urinary tract can mimic possible lesions. Three uremic patients without urinary secretions but with hematuria underwent PET examinations and were enrolled to investigate the accuracy of diagnosing urological tract tumors by this procedure in our institution. The pathological lesions of these 3 uremic patients (a 68-year-old female, with BUN/Cr of 24/4.6; a 61-year-old female with BUN/Cr of 52/7.7; and a 58-year-old female with BUN/Cr of 70/8.6) were definitively localized by PET preoperatively. We herein present 3 cases of urinary tract tumors diagnosed by PET examinations.