Ng C S, Doyle T C, Pinto E M, Courtney H M, Miller R, Bull R K, Freeman A H, Dixon A K
Department of Radiology, Addenbrooke's NHS Trust and the University of Cambridge, Cambridge, UK.
Clin Radiol. 2002 May;57(5):359-64. doi: 10.1053/crad.2001.0841.
Frail, elderly and immobile patients frequently have difficulty in tolerating formal colonic investigations. Caecal tumours may account for up to 35% of colonic tumours. Barium enema and colonoscopy have limitations in assessing this region. The aims of this study were to evaluate the accuracy of a minimal preparation CT technique (merely with prolonged oral contrast medium) in identifying caecal carcinomas and to determine helpful radiological signs.
The CT technique involved helical acquisition following 2 days of preparation with oral contrast medium. The outcome of 4 years' experience (1995-1998) was reviewed. The gold-standards were pathological and cancer registration records, together with colonoscopy and barium enema where available, with a minimum of 15 months' follow-up.
CT correctly identified 27 of 30 caecal carcinomas, and missed three, in a total of 1077 CT studies in 1031 patients (median age 80 years). There were also 21 false-positive cases in which CT incorrectly raised the possibility of a caecal tumour. The sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were 90%, 98%, 99% and 56%, respectively. Serosal margin blurring, tumour length, presence of abnormal peri-colic fat and terminal ileal wall thickening were identified as useful radiological signs.
Minimal preparation CT is able to identify caecal carcinomas with fair accuracy. Such evaluation may become important given the increasing population age and evidence of a 'proximal shift' in the site of colonic tumours in the elderly.
体弱、年迈及行动不便的患者常常难以耐受常规的结肠检查。盲肠肿瘤可能占结肠肿瘤的35%。钡剂灌肠和结肠镜检查在评估该区域时存在局限性。本研究的目的是评估一种简易准备的CT技术（仅延长口服对比剂时间）在识别盲肠癌方面的准确性，并确定有用的放射学征象。
CT技术包括在口服对比剂准备2天后进行螺旋扫描。回顾了4年（1995 - 1998年）的经验结果。金标准为病理及癌症登记记录，以及可获得的结肠镜检查和钡剂灌肠结果，并至少随访15个月。
在对1031例患者（中位年龄80岁）进行的1077次CT检查中，CT正确识别出30例盲肠癌中的27例，漏诊3例。还有21例假阳性病例，CT错误地提示存在盲肠肿瘤的可能性。敏感性、特异性、阴性预测值（NPV）和阳性预测值（PPV）分别为90%、98%、99%和56%。浆膜边缘模糊、肿瘤长度、结肠周围脂肪异常及回肠末端肠壁增厚被确定为有用的放射学征象。
简易准备的CT能够较为准确地识别盲肠癌。鉴于人口老龄化加剧以及老年患者结肠肿瘤部位出现“近端转移”的证据，这样的评估可能会变得很重要。
