多层CT辐射剂量与防护研究进展

多层CT(MDCT)可进行快速扫描和大范围容积扫描。与单层CT(SDCT)相比,MDCT特有的参数可能增加或减少受检者剂量。早期研究表明MDCT所致受检者剂量高于SDCT,但目前越来越多的研究表明两者剂量相似甚至MDCT的剂量较低。多层CT主要依靠CT的合理使用来降低辐射剂量。CT检查正当化判断是临床医生与放射医师共同的责任。扫描参数应根据扫描指征、受检者体形、年龄及扫描范围设置,并使用自动曝光控制等降低辐射剂量的技术。对临床医生和CT工作人员进行CT辐射防护培训有助于CT检查正当化及扫描方案与辐射剂量的最优化。

Study on Patient Dose and Radiation Protection in MDCT

Multi-detector row computed tomography(MDCT)scanners allow rapid scanning and wider scan coverage.There are a number of new influencing parameters specific to MDCT which systematically increase or decrease patient dose compared to single-detector row CT scanners(SDCT).Initial reports after the introduction of MDCT indicated increased patient doses relative to SDCT;more recent reports show comparable or decreased patient doses.In MDCT,the actual dose reduction depends upon how the CT system is used to be appropriate to the diagnostic task.Justification of CT study is a shared respon- sibility between requesting clinicians and radiologists.Scanning parameters should be based on study in- dication,patient size,patient age and body region being scanned so that radiation dose can be adapted based on these parameters.MDCT offers a number of technical measures for dose reduction,the most important of which is Automated Exposure Control(AEC).Training of requesting physician and CT staff about CT radiation protection can help in justification of CT study for a given indication and optimization of protocols and radiation dose.