Department of Nuclear Medicine and PET Center, Shin Kong Wu Ho-Su Memorial Hospital, No. 95 Wenchang Rd, Shilin District, Taipei 111, Taiwan.
Radiology. 2011 May;259(2):525-33. doi: 10.1148/radiol.11101193. Epub 2011 Mar 15.
To compare the diagnostic accuracy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in the detection of colon lesions with that of delayed PET/computed tomography (CT) performed after the administration of a laxative-augmented contrast medium.
All patients gave written informed consent according to the guidelines issued by the institutional review board. In a prospective study performed from November 2005 to December 2006, images obtained in 847 patients were reviewed by two physicians in consensus. Colorectal FDG uptake on initial PET images that exceeded background FDG accumulation was graded as minimal, equivocal, or positive. When the initial PET scan revealed a colorectal region of increased uptake, either oral or anal laxative-augmented contrast medium was administered on the basis of the site of colorectal FDG focus and delayed PET/CT was performed. Initial PET findings were reevaluated and revised when necessary. Comparison was performed on a per-patient basis. Findings at histopathologic analysis and clinical follow-up served as the reference standard. The accuracy of PET was compared with that of PET/CT by using the McNemar test.
Colorectal FDG foci were seen on initial images in 137 patients. Uptake on the initial images was reported as minimal in 14 patients, equivocal in 68, and positive in 55. With use of a laxative-augmented contrast medium and delayed PET/CT, the proportions of equivocal and positive results decreased by 84% (57 of 68 patients) and 58% (18 of 31 patients), respectively. The accuracy of delayed PET/CT in the depiction of colorectal cancer was greater than that of initial PET (93.4% [128 of 137 patients] vs 71.5% [98 of 137 patients], respectively; P < .01).
Delayed PET/CT with laxative-augmented contrast medium is more accurate than initial PET alone in the detection of colorectal cancer. This approach has promise as a tool for guiding decisions about how to treat patients with colorectal FDG foci.
http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101193/-/DC1.
比较氟 18 氟脱氧葡萄糖（FDG）正电子发射断层扫描（PET）探测结肠病变的诊断准确性与在给予泻剂增强对比剂后行延迟 PET/计算机断层扫描（CT）的诊断准确性。
所有患者均根据机构审查委员会发布的指南签署了书面知情同意书。2005 年 11 月至 2006 年 12 月进行的一项前瞻性研究中，由两位医师共同对 847 例患者的图像进行了回顾性分析。初始 PET 图像上结肠摄取 FDG 高于背景 FDG 摄取程度被分为轻度、不确定和阳性。当初始 PET 扫描显示出结直肠摄取增加区域时，根据 FDG 摄取的结直肠部位给予口服或肛门泻剂增强对比剂，然后进行延迟 PET/CT。必要时重新评估初始 PET 结果并进行修订。在患者层面上进行比较。以组织病理学分析和临床随访结果作为参考标准。使用 McNemar 检验比较 PET 和 PET/CT 的准确性。
137 例患者的初始图像上可见结直肠 FDG 摄取灶。14 例患者的初始图像摄取结果为轻度，68 例为不确定，55 例为阳性。使用泻剂增强对比剂和延迟 PET/CT 后，不确定和阳性结果的比例分别降低了 84%（68 例中的 57 例）和 58%（31 例中的 18 例）。延迟 PET/CT 对结直肠癌的显示准确性大于初始 PET（分别为 93.4%[137 例中的 128 例]和 71.5%[137 例中的 98 例]；P<.01）。
与单独使用初始 PET 相比，使用泻剂增强对比剂的延迟 PET/CT 更能准确探测结直肠癌。这种方法有望成为指导治疗结直肠 FDG 摄取灶患者的一种工具。
http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101193/-/DC1.
