Debrey Sarah M, Yu Hua, Lynch John K, Lövblad Karl-Olof, Wright Violet L, Janket Sok-Ja D, Baird Alison E
Stroke Neuroscience Unit, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, MD, USA.
Stroke. 2008 Aug;39(8):2237-48. doi: 10.1161/STROKEAHA.107.509877. Epub 2008 Jun 12.
Accurate diagnosis of the degree of internal carotid artery (ICA) stenosis is needed for decisions regarding optimal stroke prevention. Noninvasive magnetic resonance angiography (MRA) is being proposed and used as a replacement for the gold standard, intra-arterial angiography. Our purpose was to perform a systematic review and diagnostic meta-analysis to determine the sensitivity and specificity of time-of-flight (TOF) MRA and contrast-enhanced (CE) MRA for the detection of (1) high-grade (> or = 70% to 99%) ICA stenoses; (2) ICA occlusions; (3) moderately severe (50% to 69%) ICA stenoses; and (4) compare the overall accuracy of the 2 MRA techniques.
The medical literature on MRA and the diagnosis of ICA steno-occlusive disease was reviewed through the PubMed, EMBASE, and SCOPUS databases. All publication years were included through to November 2006. Studies were eligible for inclusion if they compared the accuracy of TOF or CE MRA for the detection of ICA disease against intra-arterial angiography and reported sufficient data.
The overall sensitivity of TOF MRA for the detection of > or = 70% to 99% ICA stenoses was 91.2% (95% CI: 88.9% to 93.1%) with a specificity of 88.3% (86.7% to 89.7%), whereas the sensitivity of CE MRA was 94.6% (92.4% to 96.4%) with a specificity of 91.9% (90.3% to 93.4%). For the detection of ICA occlusions, the sensitivity of TOF MRA was 94.5% (91.2% to 96.8%) and the specificity was 99.3% (98.9% to 99.6%), whereas the sensitivity and specificity values for CE MRA were 99.4% (96.8% to 100%) and 99.6% (99.2% to 99.9%), respectively. For moderately severe (50% to 69%) stenoses, TOF MRA had a sensitivity of only 37.9% (29.3% to 47.1%) and a specificity of 92.1% (89.6% to 94.1%); for CE MRA, the pooled sensitivity value was somewhat better at 65.9% (57.0% to 74.0%), whereas the specificity was 93.5% (91.3% to 95.3%).
TOF MRA and CE MRA showed high accuracy for the detection of high-grade ICA stenoses and occlusions with CE MRA having the edge over TOF MRA, but had only poor (TOF MRA) to fair (CE MRA) sensitivity for the detection of moderately severe stenoses.
准确诊断颈内动脉（ICA）狭窄程度对于做出最佳的卒中预防决策至关重要。无创性磁共振血管造影（MRA）正被提议并用作金标准——动脉内血管造影的替代方法。我们的目的是进行一项系统评价和诊断性荟萃分析，以确定时间飞跃（TOF）MRA和对比增强（CE）MRA检测（1）重度（≥70%至99%）ICA狭窄；（2）ICA闭塞；（3）中度严重（50%至69%）ICA狭窄；（4）并比较这两种MRA技术的总体准确性的敏感性和特异性。
通过PubMed、EMBASE和SCOPUS数据库检索有关MRA及ICA狭窄闭塞性疾病诊断的医学文献。纳入截至2006年11月的所有发表年份的研究。如果研究比较了TOF或CE MRA检测ICA疾病相对于动脉内血管造影的准确性并报告了足够的数据，则符合纳入标准。
TOF MRA检测≥70%至99% ICA狭窄的总体敏感性为91.2%（95%CI：88.9%至93.1%），特异性为88.3%（86.7%至89.7%），而CE MRA的敏感性为94.6%（92.4%至96.4%），特异性为91.9%（90.3%至93.4%）。对于检测ICA闭塞，TOF MRA的敏感性为94.5%（91.2%至96.8%），特异性为99.3%（98.9%至99.6%），而CE MRA的敏感性和特异性值分别为99.4%（96.8%至100%）和99.6%（99.2%至99.9%）。对于中度严重（50%至69%）狭窄，TOF MRA的敏感性仅为37.9%（29.3%至47.1%），特异性为92.1%（89.6%至94.1%）；对于CE MRA，合并敏感性值稍好，为65.9%（57.0%至74.0%），而特异性为93.5%（91.3%至95.3%）。
TOF MRA和CE MRA在检测重度ICA狭窄和闭塞方面显示出高准确性，CE MRA优于TOF MRA，但在检测中度严重狭窄方面，TOF MRA敏感性差（TOF MRA）至中等（CE MRA）。
