• Journal of Korea Association of Health Promotion
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• v.4 no.1
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• pp.49-59
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• 2006

"본 논문은 대한영상의학회지 2005년 제52권 제1호에 실렸던 논문으로 대한영상의학회의 승인을 득하고 본 협회지에 게재함. Purpose: We wished to compare CT colonography with conventional colonoscopy for the detection of colorectal poiypoid lesions, and we wanted to evaluate the role of IV contrast-enhanced CT colonography for the differentiation between benign polypoid lesions and malignant polypoid lesions. Materials and Methods: Thirty-four consecutive patients underwent CT colonography prior to conventional colonoscopy, Precontrast prone-position CT images and post contrast supine position CT images were obtained and the virtual colonoscopic images were reconstructed, Axial, sagittal and presence, size and morphologic features of colorectal polypoid lesions, and thor these findings were compared with the colonoscopic findings. The degree of enhancement of colorecralpolypoid lesions was measured by subtracting the attenuation valves obtained with precontrastand postcontrast CT images for the differentiation of benignity and malignancy of the colorectal polypoid lesions. Results. Among 75 colorectal polypoid lesions identified on conventional colonoscopy, 49neoplasms were found on CT coloaographv, and the overall detection rate was 65,3%.Detection rate of lesions smaller than l0mm was 52.1%(24/46), and the detection rate for lesions equal to or larger than 10mm was 86.2%(25/29), Morphologic features of the sessile type lesions on CT colonography were well correlated with those noted on colonoscopy, but the stalks were not identified in 6 of 13 polyps on CT colonography. There was no statistical correlation between benignity and malignancy and the degree of contrast enhancement on CT colonography, Conclusion CT colonography is a useful modality for the detection of colorectal polypoid lesionsequal to or polyps. However, CT colonography cannot differentiate benignity from malignancy.

• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.179-179
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• 2003

• Korean Journal of Radiology
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• v.24 no.2
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• pp.79-82
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• 2023

• Journal of Radiation Protection and Research
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• v.38 no.4
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• pp.214-227
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• 2013

Computed tomographic scan as a screening procedures in asymptomatic individuals has seen a steady increase with the introduction of multiple-raw detector CT scanners. This report provides a brief review of the current controversy surrounding CT cancer screening, with a focus on the radiation induced cancer risks and clinical efficacy. 1. A large study of patients at high risk of lung cancer(the National Lung Screening Trial[NLST]) showed that CT screening reduced cancer deaths by 20%(1.33% in those screened compared with 1.67% in those not screened). The rate of positive screening tests was 24.2% and 96.4% of the positive screening results in the low-dose CT group were false-positive. Radiation induced lung cancer risk was estimated the most important in screening population because ERR of radiation induced lung cancer does not show the decrease with increasing age and synergistic connection between smoking and radiation risk. Therefore, the radiation risk may be on the same order of magnitude as the benefit observed in the NLST. Optimal screening strategy remain uncertain, CT lung cancer screening is not yet ready for implementation. 2. Computed tomographic colonography is as good as colonoscopy for detecting colon cancer and is almost as good as colonoscopy for detecting advanced adenomas, but significantly less sensitive and specific for smaller lesions and disadvantageous for subsequent therapeutic optical colonoscopy if polyps are detected. The average effective dose from CT colonography was estimated 8-10 $mS{\nu}$, which could be a significant dose if administered routinely within the population over many years. CT colonography should a) achieve at least 90% sensitivity and specificity in the size category from 6 and 10 mm, b) offer non-cathartic bowl preparation and c) be optimized and standardized CT parameters if it is to be used for mass screening. 3. There is little evidence that demonstrates, for whole-body scanning, the benefit outweighs the detriment. This test found large portion of patient(86~90.8%) had at least one abnormal finding, whereas only 2% were estimated to have clinically significant disease. Annual scans from ages 45 to 75 years would accrue an estimated lifetime cancer mortality risk of 1.9%. There is no group within the medical community that recommends whole-body CT. No good studies indicate the accuracy of screening CT, at this time. The benefit/risk balance for any of the commonly suggested CT screening techniques has yet to be established. These areas need further research. Therefore wild screening should be avoided.