Iannaccone Riccardo, Laghi Andrea, Catalano Carlo, Brink James A, Mangiapane Filippo, Trenna Simona, Piacentini Francesca, Passariello Roberto
Department of Radiological Sciences, University of Rome-La Sapienza, Policlinico Umberto I, Viale Regina Elena 324, Rome, Italy 00161.
Radiology. 2003 Dec;229(3):775-81. doi: 10.1148/radiol.2293021399.
To compare the performance of lower-dose multi-detector row helical computed tomographic (CT) colonography with that of conventional colonoscopy in the detection of colorectal lesions.
One hundred fifty-eight patients underwent multi-detector row helical CT colonography (beam collimation, 4 x 2.5 mm; table feed, 17.5 mm/sec; voltage, 140 kV; and effective dose, 10 mAs) followed by conventional colonoscopy. Conventional colonoscopy served as the reference standard. Two radiologists interpreted CT colonographic images to assess the presence of polyps or carcinomas. Sensitivity was calculated on both a per-polyp and a per-patient basis. In the latter, specificity and positive and negative predictive values were also calculated. Weighted CT dose index was calculated on the basis of measurements obtained in a standard body phantom. Effective dose was estimated by using commercially available software.
CT colonography correctly depicted all 22 carcinomas (sensitivity, 100%) and 52 of 74 polyps (sensitivity, 70.3%). Sensitivity for detection was 100% in all 13 polyps 10 mm or larger in diameter, 83.3% in 20 of 24 polyps 6-9 mm, and 51.3% in 19 of 37 lesions 5 mm or smaller. With regard to the per-patient analysis, CT colonography had a sensitivity of 96.0%, a specificity of 96.6%, a positive predictive value of 94.1%, and a negative predictive value of 97.7%. The total weighted CT dose index for combined prone and supine acquisitions was 2.74 mGy. The simulated effective doses for complete CT colonography were 1.8 mSv in men and 2.4 mSv in women.
Lower-dose multi-detector row helical CT colonography ensures substantial dose reduction while maintaining excellent sensitivity for detection of colorectal carcinomas and polyps larger than 6 mm in diameter.
比较低剂量多排螺旋计算机断层扫描（CT）结肠成像与传统结肠镜检查在检测结直肠病变方面的性能。
158例患者先接受多排螺旋CT结肠成像检查（束准直，4×2.5mm；床速，17.5mm/秒；电压，140kV；有效剂量，10mAs），随后进行传统结肠镜检查。传统结肠镜检查作为参考标准。两位放射科医生解读CT结肠成像图像以评估息肉或癌的存在情况。分别基于每个息肉和每位患者计算敏感性。对于后者，还计算特异性、阳性预测值和阴性预测值。根据在标准人体模型中获得的测量值计算加权CT剂量指数。使用商用软件估计有效剂量。
CT结肠成像正确显示了所有22例癌（敏感性，100%）以及74例息肉中的52例（敏感性，70.3%）。直径10mm或更大的所有13例息肉的检测敏感性为100%，24例6 - 9mm息肉中的20例敏感性为83.3%，37例5mm或更小病变中的19例敏感性为51.3%。关于每位患者的分析，CT结肠成像的敏感性为96.0%，特异性为96.6%，阳性预测值为94.1%，阴性预测值为97.7%。俯卧位和仰卧位联合采集的总加权CT剂量指数为2.74mGy。完整CT结肠成像的模拟有效剂量男性为1.8mSv，女性为2.4mSv。
低剂量多排螺旋CT结肠成像在确保大幅降低剂量的同时，对直径大于6mm的结直肠癌和息肉保持出色的检测敏感性。
