多排螺旋CT血管造影评估静脉血栓栓塞的扫描技术及影像学特点

Scanning technique and imaging characteristics of multi-slice spiral CT angiography in assessing venous thromboembolism

学术背景:影像学检查在静脉血栓栓塞诊断中起了重要作用,以往应用动脉血管造影、核素扫描及磁共振扫描等方法,但均存在一定缺陷。目的:评价多排螺旋血管造影对静脉血栓栓塞早期诊断的价值,并介绍多排螺旋CT的扫描技术及影像学特点等方面的最新进展。检索策略:由第一、二作者应用计算机检索Medline1998-01/2007-10与静脉血栓栓塞诊断相关的文章,检索词"venous thromboembolism,(pulmonary thromboembolisis,CT angiography",限定语言种类为"English"。同时通过手工和计算机对万方数据库2000-01/2007-10的相关文章进行检索,检索词"静脉血栓栓塞,CT血管造影,诊断",限定语言种类为中文。纳入标准:内容与静脉血栓栓塞和肺血栓栓塞的诊断有关。排除标准:较陈旧的文献和重复研究。文献评价:初检得到228篇相关文献,其中机检172篇,手检56篇;包括中文74篇,英文154篇。阅读标题和进行初选,排除因研究目的与本文无关的144篇,内容重复者38篇,保留56篇中英文文献进一步查找全文,纳入24篇完全符合要求的文献进行综述,其中6篇是综述和述评类文献,其余18篇是关于静脉血栓栓塞临床、影像和病理诊断方面的研究。资料综合:多排螺旋CT利用多排采集技术,结合高质量的三维重建图像,能清晰地显示肺动脉远端分支,使肺栓塞的诊断进一步达到了亚段水平。薄层螺旋CT诊断肺栓塞的敏感性与肺动脉血管造影相比没有显著差异,其敏感性和特异性都高于肺通气/灌注核素扫描,且在排除急性肺栓塞时,螺旋CT有可能替代核素扫描成为检查的首选。总的来讲CT灌注扫描已成为肺栓塞影像诊断研究的新方向。结论:螺旋CT扫描速度快,图像清晰,不遗漏小病灶。螺旋CT血管造影是静脉血栓栓塞安全、迅速、无创伤的有效诊断方法。

BACKGROUND： Imaging examination plays an important role in the diagnosis of venous thromboembolism. However, there are some limitations in arterial angiography, radioisotope scanning and magnetic resonance imaging. OBJECTIVE： To assess the significance of multi-slice spiral CT angiography in the early diagnosis of venous thromboembolism, and introduce the latest progresses in the multi-slice spiral CT scanning and imaging characters. RETRIEVAL STRATEGY： A computer-based online search of Medline was undertaken for the English articles published from January 1998 to October 2007 with the keywords of ＂venous thromboembolism （pulmonary thromboembolism）, CT angiography＂. Meanwhile, we searched Wanfang database manually and by computer for the Chinese articles dated from January 2000 to October 2007 with the keywords of ＂venous thromboembolism, CT angiography, diagnosis＂ in Chinese. Articles about the diagnosis of venous thromboembolism and pulmonary thromboembolism were selected, and outdated articles and repetitive studies were excluded. LITERATURE EVALUATION： 228 articles were collected including 172 from internet and 56 from manual search. There were 74 Chinese articles, and 154 English. After the first trial on the titles and abstracts, 144 with unrelated study object and 38 repetitive studies were eliminated. Fifty-six Chinese and English articles were included for further search of full-texts. Finally, 24 articles accorded with the inclusive criteria were selected and reviewed including 6 review and comment articles, and 18 studies on the clinical, imaging and pathological diagnosis of venous thromboembolism. DATA SYNTHESIS： With multi-slice collection technique, spiral CT can clearly display pulmonary arterial distal branch in combination with high-quality three-dimensional reconstruction imaging, and improve the diagnosis of pulmonary thromboembolism to sub-segmental level. Thin layer spiral CT shows no significant differences in the sensitivity in the diagnosis of pulmonary thromboembolism compared with pulmonary angiography. Its sensitivity and specificity are higher than lung ventilation/perfusion radioisotope scanning. Moreover, spiral CT is the first option for examination when eliminating acute pulmonary embolism. Generally speaking, CT perfusion scanning has become a trend for the diagnosis of pulmonary thromboembolism. CONCLUSION： Spiral CT presents fast scanning with clear images and avoids omitting small focus. CT angiography is a safe, rapid, atraumatic, and effective diagnosis for venous thromboembolism.