Florie Jasper, van Gelder Rogier E, Schutter Michiel P, van Randen Adrienne, Venema Henk W, de Jager Steven, van der Hulst Victor P M, Prent Anna, Bipat Shandra, Bossuyt Patrick M M, Baak Lubbertus C, Stoker Jaap
Department of Radiology, Academic Medical Center, G1-230, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands.
Eur Radiol. 2007 Dec;17(12):3112-22. doi: 10.1007/s00330-007-0668-0. Epub 2007 Jun 5.
The purpose was to evaluate low-dose CT colonography without cathartic cleansing in terms of image quality, polyp visualization and patient acceptance. Sixty-one patients scheduled for colonoscopy started a low-fiber diet, lactulose and amidotrizoic-acid for fecal tagging 2 days prior to the CT scan (standard dose, 5.8-8.2 mSv). The original raw data of 51 patients were modified and reconstructed at simulated 2.3 and 0.7 mSv levels. Two observers evaluated the standard dose scan regarding image quality and polyps. A third evaluated the presence of polyps at all three mSv levels in a blinded prospective way. All observers were blinded to the reference standard: colonoscopy. At three times patients were given questionnaires relating to their experiences and preference. Image quality was sufficient in all patients, but significantly lower in the cecum, sigmoid and rectum. The two observers correctly identified respectively 10/15 (67%) and 9/15 (60%) polyps > or =10 mm, with 5 and 8 false-positive lesions (standard dose scan). Dose reduction down to 0.7 mSv was not associated with significant changes in diagnostic value (polyps > or =10 mm). Eighty percent of patients preferred CT colonography and 13% preferred colonoscopy (P<0.001). CT colonography without cleansing is preferred to colonoscopy and shows sufficient image quality and moderate sensitivity, without impaired diagnostic value at dose-levels as low as 0.7 mSv.
目的是从图像质量、息肉可视化及患者接受度方面评估无需进行肠道清洁的低剂量CT结肠成像。61例计划接受结肠镜检查的患者在CT扫描前2天开始低纤维饮食，服用乳果糖和泛影酸进行粪便标记（标准剂量，5.8 - 8.2 mSv）。对51例患者的原始原始数据在模拟的2.3 mSv和0.7 mSv水平进行修改和重建。两名观察者评估标准剂量扫描的图像质量和息肉情况。第三名观察者以盲法前瞻性方式评估所有三个mSv水平下息肉的存在情况。所有观察者均不知晓参考标准：结肠镜检查。三次让患者填写关于其体验和偏好的问卷。所有患者的图像质量均足够，但盲肠、乙状结肠和直肠的图像质量显著较低。两名观察者分别正确识别出10/15（67%）和9/15（60%）个≥10 mm的息肉，标准剂量扫描时有5个和8个假阳性病变。剂量降至0.7 mSv与诊断价值（≥10 mm的息肉）的显著变化无关。80%的患者更喜欢CT结肠成像，13%的患者更喜欢结肠镜检查（P<0.001）。无需肠道清洁的CT结肠成像比结肠镜检查更受青睐，显示出足够的图像质量和中等灵敏度，在低至0.7 mSv的剂量水平下诊断价值不受损害。
